Purpose: Silicon carbide grinding wheels are tools used in manufacturing industry to form precision componentsand continue to be used to increase production rates due to their ability to remove high volumes of material athigh speeds. There is a demand to increase the speed of rotation of the grinding wheel in order to achieve highremoval rates. The increase in speed creates a situation where the grinding machine and the operator are subjectedto a possible catastrophic failure of the wheel due to the stresses generated in the coarse brittle structure of thevitrified grinding wheel. The study focused on building and analyzing computer models of grinding wheels withrecessed features spinning at different rotational speeds. By employing a computational approach, it was possibleto determine the maximum principal stresses in the wheel together with the location of the stresses. The geometryof vitrified wheels considered included a plain-sided rotating wheel and a recessed rotating wheel.Design/methodology/approach: The paper shows how stresses and factors of safety are calculated in order topredict the bursting speeds of small recessed SiC grinding wheels. The main methods used include finite elementanalysis and mechanical testing of abrasive materials. The approach of the paper is to integrate the use of numericalanalysis techniques and experimental techniques to predict the safe operating conditions of SiC abrasive products.Findings: Calculations were conducted to determine maximum stress in parallel-sided and recessed cup wheels.Relevant factors of safety and bursting speed were also calculated and compared with experimental data. Thepaper proves the usefulness and applicability of a method developed for taking account of stress concentrationsat the recess of small cup-shaped silicon carbide grinding wheels.Research limitations/implications: The paper is limited to analyzing small recessed SiC grinding wheels.Further work should focus on large recessed wheels and wheels made with different abrasive grains and bondingmaterials. The type of porosity distribution should also be investigated.Practical implications: The paper shows how numerical methods are used to design safe operating conditionsfor brittle grinding wheels. The methods used show that numerical techniques are suitable for calculating themeasures of safety that are an important consideration when designing high speed rotating grinding wheels thatcan be devastating if allowed to fail in service.Originality/value: The originality in the paper is revealed owing to the fact that fracture mechanics principlesare applied to the prediction of failure of rotating grinding wheels. The paper is of practical importance tomechanical designers who are responsible for the safe design of grinding wheels.

Numerical analysis --- Finite element methods --- Grinding wheels --- Silicon carbide --- Fracture

Purpose: The main purpose of the presented paper was the determination of the influence of the phase transformation kinetics, at tempering, on the properties of high-speed steels. In order to achieve this aim investigations of the influence of continuous heating and isothermal tempering from the as-quenched state on the investigated steels hardness were performed. The advancement degree change obtained by changing the heating rate and by pre-tempering was applied in strength properties studies.Design/methodology/approach: Due to a high brittleness of tested steels it was decided to test their strength by means of the static bend test. The tests were carried out on 5 samples using the INSTRON testing machine. The microstructure of investigated steels in the as-quenched state was examined by the light microscope Axiovert 200 MAT and the scanning electron microscope Hitachi 3500 N. The measurements of hardness were performed with the Vickers HPO250 apparatus.Findings: Changing heating rates for tempering one can influence steel properties. Better results are achieved when steels are heated up to the tempering temperature with the higher rate. The heating rate increased from 15°C/min to 300°C/min improved the investigated steels bending strength by 8%.Research limitations/implications: Phase transformations at tempering, being diffusive transformations, are characterised by the determined kinetics depending on a temperature and time of heating. Complexity of processes occurring at tempering, as well as the diversity of influencing factors creates the possibility of searching for prolonging the life-span of tools made of high-speed steels. Regardless that only two, well known high-speed steels HS18-0-1 and HS6-5-2 were tested, the obtained results can be referred to the whole group of high-speed steels.Practical implications: On the basis of the obtained results it is possible to select the tempering parameters in such a way as to achieve the optimal combination of strength and plastic properties needed for the anticipated application of the given high-speed steel.Originality/value: This results should be of interest to engineers concerned with designing the new technologies of high-speed steels tempering

Tool materials --- Tempering --- High-speed steel --- Mechanical properties

Purpose: The purpose of this study was using of transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) in order to reveal the changes in substructure of speed steel made with deep cryogenic treatment (DCT), in comparison with substructure formed by conventional heat treatment for secondary hardness.Design/methodology/approach: The HS6-5-2 high speed steel was heat treated in a conventional mode for secondary hardness or was processed in a mode with use of DCT, with and without next tempering. Transmission electron microscopy and scanning electron microscopy observations were carried out. Studies of thermal stability in range of temperatures from -196 °C to 400 °C were performed using differential scanning calorimetry (DSC).Findings: Observations made with aid of SEM-TEM microscope revealed the presence of high density of globular clusters situated at dislocations, and precipitations of the fine carbide plates, located in twinned crystals of martensite. Thermal analysis (DSC) showed an occurrence of higher exothermic effects in specimens treated with use of DCT, than in specimens heat treated conventionally. In steel samples after quenching and DCT the additional exothermic effect was observed. Electron diffraction in TEM studies of these specimens allowed to observe reflections of which indexing exhibited that the precipitated carbide phase has crystallographic structure of B1 type.Research limitations/implications: Extremely high dispersion of carbide phases and a high state of stress that accompanies the stage of precipitation, make difficult the identification of the lattice structure of precipitations, its crystallographic relationships and the degree of coherence with the matrix. Identification of the type of carbides (ε, η, B1, and others) and their coherence with matrix become time-consuming. This important issue requires detailed studies using high-resolution microscopes. Conditions of the early stage of the precipitation process affect the stability of induced strengthening and service-life of tools.Practical implications: Research of HS6-5-2 high speed steel allowed concluding that DCT, besides refinement of martensite grain size, causes an increase of quantity of sites for nucleation of clusters, in which during tempering the B1 carbides are formed. These fine, coherent with matrix and stable carbides are found to be responsible for enhancement of toughness and wear resistance of HSS tools.Originality/value: The issue of DCT is a niche topic in Poland, there are no detailed studies on the changes taking place during this process.

Tool materials --- High speed steel --- Deep cryogenic treatment --- Carbides

diversity among the diversity of other extraterrestrial carbon phases. The main subject of research shown here are example meteorites consisting diamonds: ureilites DaG 868 and Dho 3013. Results are compared with previous investigations. Diamonds exist in many different meteorites, interplanetary dust particles (IDPs) and in comets dust. Origin of different diamonds is still debated among the scientists, two main possibilities are taken into consideration CVD process or shock metamorphism. Understanding laboratory techniques of manufacturing diamond helps in understanding the processes taking place in the Space. From the other side, the new findings and discoveries give the new insight to material science and laboratory techniques.Design/methodology/approach: The samples were examined with different methods, the most investigations presented here are Raman Mapping and Cathodoluminescence (CL).Findings: Diamonds have been found in different samples with different shock stages. It means that not all diamonds in urelites could have shock origin. Diamonds from examined samples show high diversity, they exist in different sizes, from nanodiamonds to micrometer sizes diamonds and in different polytypes. Shifts of Raman diamond peaks indicates this.Research limitations/implications: Results show the possibilities of creating the new diamond-based materials similar to those found in meteorites. Diamond polytypes are not well characterized yet and could give some surprises for materials science. For future research it would be interesting to apply more methods such as X-ray diffraction or HRTEM.Originality/value: SEM+BSE+EDS+CL results and Raman imaging results of DaG 868 and Dho 1303 ureilites are shown for the first time.

Nanomaterials --- Diamond --- Polytypes --- Meteorite

crack resistance of C-Mn constructional steels with microaddition of boron assigned to be used in production of high strength steel plates.Design/methodology/approach: Metallographic observations, heat treatment, hardness measurements, impact strength examinations, fractographic analyses of fracture surfaces of test pieces have been performed.Findings: Dispersive particles of interstitial phases formed on dislocations during the plastic deformation, limiting grain growth of austenite, create the possibility to obtain metallurgical products with fine-grained microstructure giving them high strength and guaranteed crack resistance, also at low temperature.Research limitations/implications: Further research of microstructure in transmission electron microscope as well as complementary impact resistance tests at the temperature lower than -60°C are foreseen to be performed.Practical implications: Obtained results of examinations, especially detailed fractographic analysis of fracture surfaces of test pieces together with chemical composition analysis of revealed non-metallic inclusions and precipitations of secondary phases will make contribution to better understanding of cracking mechanisms in the group of high-strength steels.Originality/value: Performed research revealed that investigated steels present high crack resistance also at low temperature. It can be achieved through proper selection of chemical composition and adequate conditions of heat treatment and plastic working. The presence of microadditions of transition metals deriving from IVb and Vb group of periodic classification of the elements with high chemical affinity to nitrogen and carbon allows producing rolled products with high exploitation properties.

Metallic alloys --- Heat treatment --- Microalloyed steels --- Heavy plates --- Crack resistance

Purpose: The paper briefly presents results of the new developed high quality cast materials.Design/methodology/approach: The following materials are: hypereutectoid cast steel with various microstructure modular graphite obtained in as-cast condition (raw state), ductile cast iron of bainite-martensitic carbides structure obtained in a raw state, aluminum bronzes and silumins with additives of: chromium, molybdenum, wolfram, vanadium.Findings: These alloys are characterized primarily by significant mechanical properties and high wear resistance. It was also discussed getting of layer products by combination of steel or cast iron using alphinated layer with silumin.Practical implications: The paper discusses the high quality cast alloy, layer products and presents the high quality casting materials in the point of view principles of materials selection.Originality/value: The above problem is shown in the background of “Rules of material selection” as well as a model of production system in company.

Hypereutectoid cast steel with graphite --- Ductile cast iron with carbides --- Bronzes --- Mechanical properties

Purpose: The goal of this paper is to present general overview of research results on Polymeric Gradient Materials (PGMs) performed in Division of Metallic and Polymeric Materials Processing of Silesian University of Technology. Achievements in research on production technologies, compositions and properties are presented.Design/methodology/approach: Two basic technologies that were used for preparing polymeric gradient composites filled with powders are presented (centrifugal and gravity casting). Composites based on epoxy resin and filled with iron, ferrite, graphite, coal powders are characterized. Among other, the following properties were tested: surface resistivity, coefficient of friction, magnetic induction, filler particles distribution in polymeric matrix and others.Findings: Casting methods presented in this article can successfully be used to produce polymer composites characterized by gradual distribution of powder content and by this way by gradual distribution of properties. Results show that it is possible not only to achieve but also in some extend to control gradient of filler concentration. Especially in centrifugal casting is possible to influence gradient of filler concentration and in this way gradient of many properties.Research limitations/implications: The main problem in presented researches was to introduce higher quantities of filler. The side effect of high filler content was high viscosity. Filler particles were added to the epoxy matrix in range from 3vol.% to 50vol.% depending on filler properties, method of casting etc.Practical implications: Elaborated PGMs may be applied in many fields such as medicine, electronics, mining industry, machine building industry and many others.Originality/value: New type of polymeric gradient composites were achieved using centrifugal and gravity casting technique. Influence of casting parameters, concentration and type of filler on composites properties was researched.

Polymers --- Composites --- Polymeric Gradient Materials --- Casting

(TiHA) to develop a novel bone cement. Results of previous studies showed that bioactive potential of titanium modified hydroxyapatite ceramics is higher than that of pure HA. Calcium sulfate hemihydrate is also considered as a safe, biocompatible material, however it has been criticized for its rapid resorption. Combination of these materials may result in new cement type material with surgical handiness and selective resorption.Design/methodology/approach: TiHA was obtained by a wet method. Three compositions with different CSH:TiHA weight ratios, namely 3:2, 2:3 and 1:4 were examined. Pure CSH was used as a reference. Distilled water and Na2HPO4 solutions were applied as liquid phases. The study presents the setting time (Gillmore apparatus), phase composition (XRD), microstructure (SEM), porosity (mercury porosimetry) and compressive strength of the obtained new, cement type, implant material.Findings: Initial (I) and final (F) setting times of the obtained cements differed in the range of 2-16 min (I) and 4-75 min (F). The phase composition of the hardened cement bodies characterized by XRD method revealed the presence of calcium sulfate dihydrate (CSD) and hydroxyapatite. Scanning electron microscopy images show excellent bonding between needle-like CSD crystals and apatitic phase. Porosity of the final samples varied from 49 to 59% with pore size diameter from 5 nm to 3.0 μm. Compressive strength of the samples differed in the range of 3.81-7.58 MPa.Research limitations/implications: The obtained results suggest that CSH-TiHA cements have the potential to be applied in bone substitution and for delivery of drugs. Bioactivity and biodegradation of the studied materials should be checked.Originality/value: According to our knowledge, these are the first studies concerning surgical handiness of bone implant materials based on calcium sufate hemihydrate and titanium doped hydroxyapatite. The cement type composites are biocompatible, shapeable and easy to apply and adapt in bone defects.

Bone substitute --- Titanium modified hydroxyapatite --- Calcium sulfate

Purpose: The purpose of this article was to review some of the modification methods applied to improve mechanical, barrier and/or surface properties of polylactide (PLA).Design/methodology/approach: The presented modification methods were classified into three groups due to the dominant role of compositional, physical or chemical factor effecting the most PLA properties.Findings: It was found that incorporation of small amounts of montmorillonite up to 5% leads to formation of a nanocomposite with enhanced tensile strength and improved barrier properties. Corona treatment of pure PLA and PLA contained MMT nanofiller causes a significant decrease in the water contact angle and does not essentially affect the diiodomethane contact angle. This treatment leads to an increase in surface free energy that is much more significant for pure PLA than for PLA containing MMT nanofiller. It was also found that with increasing number up to 1000 of laser pulses of energies 5 mJ/cm2 an increase in surface free energy was observed, while the next laser pulses caused decrease of this energy. The determination and comparison of the influence of 3 wt.% of trimethylopropane trimethacylate (TMPTA) and 3 wt.% of trially isocyanurate (TAIC) crosslinking agents on the thermomechanical properties of electron beam irradiated PLA was reported.Research limitations/implications: A number of various modification methods are widely reported in literature. In this article a review of only such modification methods is presented, which are in line with the newest trends in polymer industry and science.Practical implications: There are a number of PLA properties, which need to be improved to satisfy specific application conditions. For that reasons researches are leading to find suitable modification methods to improve selected properties of PLA.Originality/value: This article presents some of modification methods, which are in line with the newest trends in polymer industry and science.

Engineering polymers --- Nanocomposite --- Corona discharge --- Laser modification --- Electrons irradiation --- Reactive extrusion

frictional attachments.Design/methodology/approach: The examinations of retention characteristics of traditional attachments, elastic frictional attachments and models of overdentures have been carried out using Zwick testing machine. Retention forces and work essential for separating the attachments have been determined as well. Next the force – displacement characteristics for overdenture model have been registered for two places where the force was applied and for three inclination angles of the line of application of force.Findings: The obtained results of laboratory examinations gave evidence of high effectiveness of elastic frictional attachments.Research limitations/implications: It has not been possible to register mechanical characteristics due to limitations of clinical conditions. Wide analysis of retention characteristics requires examinations carried out in laboratory conditions.Practical implications: Thorough analysis of force - displacement characteristics enables to understand better the mechanisms which are essential for the effectiveness of particular attachments. Applying such knowledge in practice helps to use more effectively the properties of silicone rubbers for making the elastic frictional attachments.Originality/value: The presented method of evaluating the effectiveness of attachments is based on determining retention work of the attachments and it allows to compare quite objectively even relatively different solutions. The so far used criterion of measuring vertical retention force makes it possible to compare only the solutions which are based on similar mechanical principles.

Mechanical properties --- Biomaterials --- Overdenture --- Implant --- Attachment

Purpose: The main goal of research is determination of the influence of frictional pair „endoprosthesis head - acetabular cup” material on frictional resistance and endoprostheses wear, and the stress distribution in the elements of “bone-cement-implant” system.Design/methodology/approach: In the paper new development directions in endoprostheses are discussed with respect to construction of “head-acetabular cup” system and endoprosthesis stem, and proper material selection. The tests were carried out using dedicated simulator of the hip endoprosthesis. A quantitative and qualitative analysis of wear products was carried out. The numerical calculations of stress state in “bone-cement-implant” system were performed using ADINA System. Additionally the impact of incorrect endoprosthesis setting (jaw angle of the stem and cup) on frictional moment was determined experimentally. The stress distribution, in particular parts of “bone-cement-implant” system for selected endoprosthesis stem constructions, was presented.Findings: Both the numerical calculations and tests carried out on the hip endoprosthesis simulator gave us many valuable information on frictional resistance value, wear mechanism and durability of new endoprostheses constructions.Research limitations/implications: Preservation of geometrical, material and tribological similarity to the natural joints is of great significance in design of hip endoprostheses. Despite significant progress in material engineering not all similarity conditions were achieved. The replacement of a specific bone structure and natural joint with polyurethane insert and metal elements (stem, head of endoprosthesis), i.e. materials with much higher modulus of elasticity, cause the significant increase of the “bone-cement-implant” system rigidity. Frictional and wear processes occurring in the moveable system: “head-acetabular cup” and the resulting low endoprosthesis durability pose a serious problem.Practical implications: Future development of endoprostheses alloplasty is determined by the progress in biotribology, especially frictional and wear tests of endoprostheses.Originality/value: The tests were carried out using the hip endoprosthesis simulator, which reflects processes occurring in natural joint.

Hip endoprostheses --- Friction --- Wear --- Wear products --- Biomaterials --- Numerical simulations

Purpose: The analyse of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of 520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitative evaluation of the microstructure. Tests of resistance to abrasive wear were carried out at the Amsler stand.Findings: The obtained test results confirm that these methods can be effectively used in shaping the pearlitic structure and properties of the steel.Practical implications: In physical modelling of tests of resistance to abrasive wear for the steel grade R260 after hot rolling and isothermal annealing it has been proved that this feature is a function of the steel structure and properties in the given operation conditions. The resistance to abrasive wear of steel R260 with a pearlitic structure and different pearlite morphology decreases with the increase of load and slide.Originality/value: An advantageous pearlitic morphology of steel (block sections) with interlamellar distance in the order of 0.12-0.13 μm, ensuring hardness of about 340-350 HB, is facilitated by a hot rolling process combined with isothermal annealing.

Pearlite morphology --- Abrasive wear --- Railroad switches --- Block sections

Purpose: of this paper was the follow up of biologic compatibility and functional use of new type endoprosthesis in a canine model.Design/methodology/approach: Prospective animal study with evaluation of new type ZRM of titanium alloy cementless total hip replacement (THR) in dogs in 2007. We used congruent ceramic head and polyethylene acetabular inlay. That is the gold standard in THR. The methods of X ray imaging evaluation after implantation and overgrowth evaluation were employed. We evaluated loading and use of the leg during walking and running. Total hip joint replacements were implanted in 6 dogs – German Shepards under general anesthesia. The follow up time was 6 months. We compared X ray findings after the operation and after 6 months, wound healing, use of THR during leg loading and biocompatibility of THR in femur and pelvis.Findings: The femoral and acetabular components were anchored using a press-fit technique. We found good biocompatibility in 5 dogs with good loading during walking and running, one complication with femoral fracture and wound abscess. At six months, there was good bony ongrowth of the THR in 5 dogs and small overgrowth on the surface of THR in one dog, deemed as complication. In the same animal, explanation of the THR was performed, due to fracture.Research limitations/implications: This study was not monitored. In the future, we would like to perform a randomized study design with a control group.Practical implications: The new THR developed by authors can restore function in canine model of damaged hip joint. The press fit anchorage of the cup allowed firm adhesion of the cup surface to the pelvic bone and likewise, the femoral component demonstrated firm fixation in the proximal femur.Originality/value: This paper is original by presenting the first results of new THR in canine model. The value of this paper is in laying groundwork for human study in the future.

THR --- Canine model --- Biocompatibility

Purpose: The paper presents the results of studies on the structure and properties of the nickel Ni-P surface layers and composite Ni-P/Si3N4 surface layers deposited on the surfaces of aluminum 1200 (A2) and its 7075 (PA9) alloy by the electroless method.Design/methodology/approach: The aluminum substrate, the sample surfaces were treated by: degreasing, etching and zincking. The composite layers were produced from a disperse Si3N4 ceramic phase with an amorphous structure and nanometric size grains.Findings: The structure of the ceramic disperse phase Si3N4 and the layer materials was determined. The topography and morphology of the layers were examined. The content of the Si3N4 phase in the layer material was determined. The microhardness of the Ni-P and Ni-P/Si3N4 layers and of the substrate material was examined. The adhesion of the nickel phosphorus and composite layers to the aluminum substrate was determined. The results of studies of the corrosion resistance of the layers are presented. The anodic polarization characteristics, corrosion current densities and corrosion potentials were determined. The results of measurements of the impedance characteristics and the counterpart results obtained by modeling with the use of equivalent electrical circuits are presented. Both the nickel Ni-P and composite Ni-P/Si3N4 layers ensure excellent properties of the aluminum products.Practical implications: A good quality of final the nickel Ni-P surface layers and composite Ni-P/Si3N4 surface layers on the surfaces of aluminum are obtained. The surface layers are characterized by high hardness, frictional wear resistance and ensure excellent protection of the aluminum substrate against corrosion.Originality/value: The produced nickel and composite surface layers have show high hardness as well as very good resistances not only to corrosion but also to mechanical wear.

Electroless surface layers --- Nickel layers --- Composite layers --- Layer structures

Purpose: The main aim of research was to elaborate models of construction attributes selection process in ordered construction families.Design/methodology/approach: Based on selection models of quantitative construction attributes in reference to unified characteristic attributes it is possible to generate ordered construction families like: series of types, modular systems.Findings: Selection models of quantitative construction attributes were analyzed. Those methods are based on construction congruence.Research limitations/implications: The neural network model limitations come from the neural network structure. The accuracy of neural network work results vary of neural network quality. The constructional similarity model can be applied only to that states which are described by similarity theory.Practical implications: Presented method was applied in grippers series of types generation process.Originality/value: Described models give simple and quick ways to select construction attributes in ordered construction families.

Constructional design --- Series of types --- Modular systems --- Constructional similarity

Purpose of this paper: In this paper an application of the new method for solving the heat conduction equation in the heterogeneous cast-mould system, with an assumption of the ideal contact at the cast-mould contact point, is introduced. An example illustrating the discussed approach and confirming its usefulness for solving problems of that kind is also presented in the paper.Design/methodology/approach: For solving the discussed problem the homotopy perturbation method is used, which consists in determining the series convergent to the exact solution or enabling to built the approximate solution of the problem.Findings: The paper shows that the homotopy perturbation method, effective in solving many technical problems, is successful also for examining the considered problem.Research limitations/implications: Solution of the problem is provided with the assumption of an ideal contact between the cast and the mould. In further, research of the discussed method shall be employed to solve problems involving the presence of thermal resistance at the cast-mould contactPractical implications: The method allows to determine the solution in form of the continuous function, which is significant for the analysis of the cast cooling in the mould, in order to avoid the defects formation in the cast.Originality/value: Application of the new method for solving the considered problem.

Numerical techniques --- Heat transfer --- Cooling of the cast --- Homotopy perturbation method

of loading state of tissue denture foundation.Design/methodology/approach: During FEM numerical modeling there was made evaluation of loading state of denture foundation tissues pressed by a hard denture and relined by a silicone layer.Findings: Maximum shear is observed under mucous surface at bone on the side of process prominence. Soft tissues injuries and pain discomfort might result from exceeding both tolerances of pressure and shear, which maximum values are located in the opposite areas. Maximum pressure values are present in central areas at tips of edentulous ridges. The layers of relining material results in a decrease and balancing of maximum pressure values. It decreases tendencies of slip and frictional injuries occurrence by means of reducing tangential stresses on the mucous interface. Nevertheless, the transfer of part of loadings on ridges slopes results in increased shear inside of the tissue at the side of the convexity. In bone tissue at the tips of edentulous ridges there is observed decrease of principal stresses and the lack of significant changes of equivalent von Mises stresses.Research limitations/implications: One of the model simplifying assumptions was the assumption of isotropic linear elasticity of materials mechanical characteristics and denture adherence to its foundation.Practical implications: Recommended to relining are injuries occurring in the central area of bone convexities. If, in spite of a proper denture fit, there is still a typical ulceration at the side of the ridges convexity, use of relining increases shear of those area of the tissue, conducing development of a typical deep ulcer located usually from the bone towards the surface of soft tissues.Originality/value: Tangential stresses and loads on mucous surface are not the only one criterion of evaluation and diagnosis of mucous membrane loading state.

Biomaterials --- Mechanical properties --- Denture relining --- Tissue

Purpose: Working conditions of forging tools have become severer with the years. To increase their wear andheat resistance the surface of the tool is coated by CVD/PVD methods. Relatively high friction coefficientof coatings results in high friction losses and low durability of coating films due to high shear stress at tool–workpiece interface. That is why improved self-lubricating system should be developed. Combination of moderncoatings (nanostructured, nanolayers, nanocomposites, etc.) with self-lubricating tool design and application ofsolid lubricant MoS2 and WS2 graphene-like nanoparticles is very promising and effective way to solve existingforging tool problems.Design/methodology/approach: Laser micro-machining technology was applied to fabricate the network ofmicro-channels which serve like reservoirs for encapsulation of solid lubricant nanoparticles into tool body.Wide ranges of tribological tests on T-10 ball-on-disc tester were carried out to define the optimal geometryand network configuration of micro-channels ensuring generation of a lubricious transfer film at the tribologicalcontact.Findings: As a result, increased tool durability and high forging precision could be reached. Analysis of failuremechanisms for different forging tools were carried out. It was found that one of the important reasons of toolwear is a high friction coefficient between treated material and the tool. Graphene-like nanoparticles of MoS2solid lubricant were produced by Rolling Cleavage Technology. Paper consist SEM, TEM and AFM analysis ofapplied coatings and solid lubricant particles.Research limitations/implications: The continuous supply to a sliding area of nanoparticles will be for thefirst time applied to decrease high shear stress at an interface between forging tool and treated material.Thenext research step will be the transfer of the developed methods of self-lubrication from samples to real coldforging tools.Originality/value: Analysis of failure mechanisms for different forging tools were carried out.

Forging tools --- PVD/CVD coatings --- Graphene-like nanoparticles --- Solid lubricants --- Laser micromachining

Purpose: The aim is to review creep age forming theoretical fundaments as well as some of our experimental results.Design/methodology/approach: The approach consists of a brief review from basic theoretical concepts of creep and ageing processesincluding a description of anumeric closed form technique to predicting springback in creep age forming. Finally, a work flow to develop a creep age forming process and its respective experimental implementationare shown.Findings: The analytical model and workflow enabled an excellent result of springback predicted value (less than 1%).Research limitations/implications: The experiments only tested simple parts. An improved model is necessary for more complex parts.Practical implications: This work permits to study the creep age forming viability of a given process planning.Originality/value: This review summarizes the main concepts of the creep age forming process and illustrates them by the application of an analytic and numerical modelling performed as a didactic experiment.

Creep age forming --- Age forming --- Creep forming --- Springback

Purpose: Bimetallic bars which possess higher corrosion resistance and mechanical properties, it is the new kind of bimetallic bars, which are better than standard bars. The bimetallic bars are more often applied in concrete construction.Design/methodology/approach: The simulations of the bar rolling were carried out using the Forge2007® commercial program.Findings: The use of non-corrosive steel on plating layer assures receipt on a high durability and esthetics bimetallic bars.Practical implications: Bimetallic bars are chiefly used in the building industry at production of concrete constructions, and as working elements in bridge building in aggressive environment.Originality/value: Production of bimetallic bars is very difficult. One from many problems during production bimetallic bars is assurance good strength of bimetallic layer bond.

Numerical techniques --- FEM --- Bimetallic bars --- Steel - steel resistant to corrosion --- Plastic working of metals --- Hot rolling --- Numerical modelling --- Reinforcement bar

Purpose: In paper is presented technology of bimetallic layer casting in configuration: working part (layer) from ferritic or austenitic alloy steel and bearing part from grey cast iron.Design/methodology/approach: In applied technology surface layer on the basis of alloy steel at 2 or 5mm thickness was put directly in founding process of cast iron with use of preparation of mould cavity method. Quality of bimetallic layer castings was estimated on the base of ultrasonic non-destructive testing and examination of the structure and selected usable properties i.e. hardness.Findings: The results of studies and their analysis show efficiency of new, innovative technology of heat-resisting layer castings.Research limitations/implications: In further research, authors of this paper are going to application of different type of alloy steels on working part (layer) of bimetallic casting.Practical implications: On the basis of research results was affirmed that application of thinner plates i.e. about thickness 2mm causes their deformation in time of pouring, what disqualify this layer casting for industrial application. Considerably best results was obtained with use thickness of plate 5mm.Originality/value: The value of this paper resides in new effective method of manufacture of heat-resisting castings, mainly for lining of quenching car to coke production.

Casting --- Cast iron --- Austenite --- Ferrite

Purpose: To study the primary oxidation stage of Fe-Cr-C steels in more detail, to correlate the oxidation kinetics with O2 absorption, with CO2 evolution and with the morphology of the scale layers formed during the course of oxidation.Design/methodology/approach: Analysis of oxidation kinetic of Fe-Cr-C alloys containing 13 % Cr and carbon ranging from 0.15 to 1.63% at 1100°C for 3hr was carried out using a SETA¬RAM-1000 thermobalance-chromatograph. Three specimen geometries were used: cylindrical specimens, bar-like samples, wire-like samples. As a results the weight gain relations, measured rates of carbon loss, rates of oxygen absorption and morphology of the oxide scales was analysed.Findings: The oxidation rate increased with increasing carbon content in the alloys. The measured time variation of CO2 evolution showed that, during the first period of oxidation (0-40 min), a compact surface layer of FeO formed, which prohibited the free transfer of CO3 into the streaming oxidation atmosphere. The measurable CO2 evolution started between 40 and 50 min, and the most rapid evolution occurred in the intervalt = 60-90 min of oxidation. This effect corresponds well to scale-layer damage and to the maximum O2 absorption.Research limitations/implications: Results enable to interpret the primary stage of the oxidation of Fe-Cr-C alloys and to discuss the relations between the cation diffusivities in the individual oxide sublayers, i.e., in wustite, magnetite, and hematite.Originality/value: More detailed description of the primary oxidation stage of Fe-Cr-C steels.

Oxidation --- Iron-chromium-carbon --- Decarburization --- Scales morphology --- Cation diffusion

Purpose: To evaluate influence of the high-temperature oxidation, as the preliminary stage previous to coating with zinc on the change of surface layer structure as well as subsurface layer of cast iron with flake, vermicular and nodular graphite.Design/methodology/approach: The experiment was led in the temperature range: 850-1050ºC in ambient air. Samples have been taken out from the furnace separately after: 2-12 hours. After scale layer removal the hot dip zinc coating in industrial conditions has carried out. Received effects were compared to these obtained during cast iron coating without preliminary thermal processing. To observation both optical and scanning microscope was applied. Sample’s surface quality was described additionally by roughness measurements.Findings: As the consequence of conducted high-temperature oxidation in subsurface layer of cast iron pores have been created, that in result of coating in liquid zinc were filled with new phase and in this way the new zone with different properties was obtained. Cast iron layer enriched in zinc is considerably thicker than layers got with application of other methods.Research limitations/implications: It is suggested to verify the corrosion resistance of cast iron coated with zinc according to presented method and compare of got results with classic zinc coating effects.Practical implications: The proposed method consisted on combining of hot dip zinc coating of cast iron with previous high temperature oxidation makes possible creation of sub-surface layer with composite character, composed of “after –graphite” voids filled with zinc and metallic matrix, without necessity of pressure processing.Originality/value: New application of high temperature corrosion as the heat treatment improving effects obtained after cast iron zinc coating.

High temperature oxidation --- Hot dip zinc galvanizing --- Cast iron

Purpose: Friction Stir Welding (FSW) was applied austenitic stainless steels that is difficult to weld using FSW technique. Proper weld can be obtained by using appropriate welding parameter. In this paper, the effect of different tool rotational speeds, traverse speeds, compressive tool forces, and tool angles was investigated.Design/methodology/approach: The dimension of 3 mm x 75 mm x 150 mm two stainless steel plates were used and butt welded by FSW method using 7.5 kW vertical head milling machine. All welded test specimens were prepared perpendicular to the weld line in order to determine the mechanical properties and tested with 12 MPa/sec stress rate under stress control using a servo-hydraulic Instron 8801. Microstructure of the welding zone and macrograph of the heat affected zone was investigated by SEM.Findings: The average grain size in the SZ was between 3 and 7 μm, which is smaller than that in the BM. The average grain size in the HAZ was about 20 μm, which is half of that in the BM.Fine-grained microstructures are present the welded area. The dark bands observed in the weld zone were also detected the microstructure of the transition zone. Dark and narrow bands do not consist of pores or cavities. It was determined that these bands do not process an ultra fine-grained microstructure. They are Cr2O3 oxide layers which over the surface of stainless steels may have been ruptured during friction stir welding and may form bands inside the welding bead due to stirring.Research limitations/implications: The proper cooling system helps to prevent the stirrer tool from the deformation.Practical implications: The strength of the welded zone of AISI 304 stainless steel can be easily found by implementing welding design parameters and high quality joints can be obtained.Originality/value: This study was performed in the frame of the TUBITAK project no 106M504, „Friction Stir Weldability of Stainless Steels and Investigation of the Affected Parameters on the Welding Quality”.

Friction Stir Welding --- AISI 304 --- Stainless steel --- Rotational tool speed --- Traverse speed

Purpose: In paper is presented problem concerning inoculation of pure aluminium primary structure, which is realized mainly by intensification of liquid metal movement in mould by use of electromagnetic field.Design/methodology/approach: In aim of realization of forced movement during the crystallization of liquid metal was used rotate electromagnetic field, which is generated by induction coil fed with frequency of supply current from 25 to 100Hz. Effect of structure refinement obtained by influence of electromagnetic field was compared with refinement obtained by use of traditional inoculation, which consists in introducing of additions in form of titanium and boron to metal bath.Findings: The results of investigations and their analysis show possibility of effective refinement of pure aluminium primary structure, only with use of electromagnetic field.Research limitations/implications: I further research, authors of this paper are going to application of introduced method of Al casting with use of electromagnetic field in continuous casting stand.Practical implications: The work presents refinement of structure method which are particularly important in continuous and semi – continuous casting where products are used for plastic forming.Originality/value: The value of this paper resides in new effective method of inoculation of pure Al, which was realized only by use of electromagnetic field.

Casting --- Aluminium --- Electromagnetic field --- Frequency

Purpose: The paper discusses two new technologies for producing magnetic materials which have been successfully developed in recent years at the Institute of Physics of the Czestochowa University of Technology and discusses properties of the materials obtained with the use of these methods.Design/methodology/approach: In this research the arc-plasma deposition of Nd2Fe14B powders onto a substrate either cooled with water or heated up to a temperature in the range from 773 to1023 K was applied. In the second method the suction of an arc-melted alloy to a water-cooled copper mould (the suction-casting method) was introduced. Moreover, microstructure, magnetic properties and domain structure of the produced samples were determined.Findings: It has been found that thin Nd2Fe14B strips obtained by the plasma method possess magnetic properties. It has also been demonstrated that the suction-casting method makes it possible to obtain both amorphous magnetically soft materials (e.g. Fe-Co-W-Zr-B), as well as magnetically hard nanocomposites (e.g. (Fe-Co)-(Pr-Dy)-B-Zr).Research limitations/implications: The main problem in the suction-casting method is to reduce the critical cooling rate required for the production of amorphous alloys and to increase the geometrical dimensions of amorphous specimens.Practical implications: Thin-layered Nd-Fe-B magnets produced by means of arc-plasma deposition can be applied directly onto the surface of electromagnetic equipment parts. Magnets with isotropic magnetic properties were obtained by applying layers onto the water-cooled copper substrate. Whereas, anisotropic magnets were obtained as a result of the arc-plasma deposition of powders onto the copper substrate heated up to 873 K. The most advantageous properties were achieved for the microcrystalline structure of a grain size close to the single-domain particle size (approx. 0.3 μm). Moreover, it has been demonstrated that the suction-casting method makes it possible to obtain bulk amorphous alloys of considerable sizes, such as rods of magnetically soft Fe-Co-W-Zr-B alloys of a diameter up to 2 mm, as well as Fe-Co-Pr-Zr-B tubes of a diameter up to 3 mm. It is also possible to produce magnetically hard nanocomposite materials of the (Fe-Co)-(Pr,Dy)-B-Zr type by annealing of metallic glasses.Originality/value: Successfully introduced new methods of magnetic materials manufacturing.

Technological devices and equipment --- Arc-plasma spraying --- Suction-casting --- Bulk amorphous alloys

Purpose: of this paper is to introduce the reader to the characteristics of PDCA tool and Six Sigma (DMAIC, DFSS) techniques and EFQM Excellence Model (RADAR matrix), which are possible to use for the continuous quality improvement of products, processes and services in organizations.Design/methodology/approach: We compared the main characteristics of the presented methodologies aiming to show the main prerequisites, differences, strengths and limits in their application.Findings: Depending on the purpose every organization will have to find a proper way and a combination of methodologies in its implementation process. The PDCA cycle is a well known fundamental concept of continuous-improvement processes, RADAR matrix provides a structured approach assessing the organizational performance, DMAIC is a systematic, and fact based approach providing framework of results-oriented project management, DFSS is a systematic approach to new products or processes design focusing on prevent activities.Research limitations/implications: This paper provides general information and observations on four presented methodologies. Further research could be done towards more detailed study of characteristics and positive effects of these methodologies.Practical implications: The paper presents condensed presentation of main characteristics, strengths and limitations of presented methodologies. Our findings could be used as solid information for management decisions about the introduction of various quality programmes.Originality/value: We compared four methodologies and showed their main characteristics and differences. We showed that some methodologies are more simple and therefore easily to understand and introduce (e.g. PDCA cycle). On the contrary Six Sigma and EFQM Excellence model are more complex and demanding methodologies and therefore need more time and resources for their proper implementation.

Quality continuous improvement --- PDCA Cycle --- EFQM Excellence Model --- RADAR Matrix --- Six Sigma