bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribological Wear Behaviour of Electrical Contacts Made from AgNi10 Composite
Authors: Richert M.W. , Boczkal G. , Hotloś A. , Pałka P. , Karpiński M.
Published: December 2017

The effect of tribological wear of contacts made from an AgNi10 alloy on microstructure and electrical properties was investigated. The contacts were tested in duty cycles loaded with alternating current of 10A intensity. With this value of the current, intensive arcing of contacts occurred. The contacts were tested in the range of 125 to 500 thousand cycles. The contacting surfaces were reported to suffer a high degree of wear, but electrical resistance of the contact system remained stable.
Microstructure and Mechanical Characterization of X70 Steel Welded Joints Through Hardness Mapping and Tensile Strength Testing
Authors: Hamdollahzadeh A. , Omidvar H. , Amirnasiri A.
Published: December 2017

In this paper, effects of preheating and type of electrode (E8010 and E8018) on microstructure and mechanical properties of 5L X70 steel welded joints were investigated. The microstructure of joint zone and fracture surface was analyzed by light optical microscope and scanning electron microscope equipped with energy dispersive spectroscopy. Hardness mapping and tensile test were also performed to find the relationship between microstructure and mechanical properties. The results showed a consistency between the hardness variation data and the microstructure of joint zone. Moreover, hardness mapping revealed coarse and fine grain subregions in the heat affected zone which were not detected in the micrographs. The tensile test indicated that the non-preheated sample, welded by cellulosic E8010, had the minimum value in the strength and the ductility of welded steel. The fractography also determined that size and distribution of strengthening phases affected the fracture mode of welded specimens.
Analytical Descriptions of Dynamic Softening Mechanisms for Ti-13Nb-13Zr Biomedical Alloy in Single Phase and Two Phase Regions
Authors: Quan G.-Z. , Wang X. , Li Y.-L. , Zhang L.
Published: December 2017

Dynamic softening behaviors of a promising biomedical Ti-13Nb-13Zr alloy under hot deformation conditions across dual phaseα+βand single phaseβregions were quantitatively characterized by establishing corresponding dynamic recovery (DRV) and dynamic recrystallization (DRX) kinetic models. A series of wide range hot compression tests on a Gleeble-3500 thermo-mechanical physical simulator were implemented under the strain rate range of 0.01-10 s−1and the temperature range of 923-1173 K. The apparent differences of flow stress curves obtained in dual phaseα+βand single phaseβregions were analyzed in term of different dependence of flow stress to temperature and strain rate and different microstructural evolutions. Two typical softening mechanisms about DRV and DRX were identified through the variations of a series of stress-strain curves acquired from these compression tests. DRX is the dominant softening mechanism in dual phaseα+βrange, while DRV is the main softening mechanism in single phaseβrange. The DRV kinetic model for single phaseβregion and the DRX kinetic model for dual phaseα+βregion were established respectively. In addition, the microstructures of the compressed specimens were observed validating the softening mechanisms accordingly.
Microstructure Characterization of Composite from ZrO2 – Ti System
Authors: Łada P. , Miazga A. , Bazarnik P. , Konopka K.
Published: December 2017

In this work the microstructure analysis of composite from ZrO2– Ti system were presented. For the preparation of the composite samples nanometric ZrO2powder stabilized by 3 mol% of Y2O3and micrometric titanium powder were used. The composites with 10 vol.% addition of titanium particles were prepared by slip casting method. The sintering process was conducted at 1450°C with 2 hours’ dwell time, in the inert atmosphere of argon. The microstructure observations were carried out with the use of SEM and STEM microscopes. The quantitative analysis and stereological characterization were performed. The SEM and STEM observations allowed characterizing the microstructure of composite samples. Especially, the interface between titanium particles and zirconia matrix was described. The growth of the zirconia grains around the Ti rich areas was observed. The increase of the zirconia grains size results from the reaction on the interface between titanium particle and zirconia matrix during the sintering process.
Evaluation of Creep Strength of Heterogeneous Welded Joint in HR6W Alloy and Sanicro 25 Steel
Authors: Zieliński A. , Dobrzański J. , Purzyńska H. , Sikora R. , Dziuba-Kałuża M. , Kania Z.
Published: December 2017

This article presents the results of investigations on HR6W alloy and Sanicro 25 steel and the dissimilar welded joint made of them. The characteristic images of microstructure of the investigated materials in the as-received condition and following the creep test, observed with a scanning electron microscope (SEM), are shown. The X-ray analysis of phase composition of the existing precipitates was carried out. The method for evaluation of creep strength based on abridged creep tests carried out at a temperature higher than the design one is presented. The obtained results do not deviate from the values of creep strength determined in long-term creep tests. The maximum difference in creep strength of the investigated materials is ±20%, which is in compliance with the acceptable scatter band. The methodology presented can be used for verification of creep strength (life time) of the material of finished components to be operated under creep conditions.
Determining the Tribological Properties of Diamond-Like Carbon Coatings Lubricated with Biodegradable Cutting Fluids
Authors: Ozimina D. , Madej M. , Kowalczyk J.
Published: December 2017

The aim of the study was to determine the effectiveness of the biodegradable cutting fluid used instead of classical, usually toxic. This paper presents the results of tribological studies of a-C:H coatings formed on HS6-5-2C steel by plasma-assisted chemical vapour deposition. The coating structures were examined using a JSM-7100F SEM. The coating microhardness was measured with a Matsuzawa tester. The surface texture analysis was performed before and after the tribological tests with a Talysurf CCI Lite optical profiler. The tribological properties were investigated using a T-01 M tester and a T-17 tester. The tests were carried out under dry friction conditions and lubricated friction conditions using a lubricant with zinc aspartate. The test results show that the layer formed at the interface prevented the moving surfaces. The investigations discussed in this paper have contributed to the development of non-toxic and environmentally-friendly manufacturing because of the use of biodegradable cutting fluid and thin, hard coatings.
Determination of Strain and Stress Fields in Welded Joints of S960-QC Steel
Authors: Pała T. , Dzioba I.
Published: December 2017

The paper presents the results of two butt welded joints by conventional method. The welding process was performed using a variety of linear welding energy. The studies included experimental and computational part. In experimental studies determined the distribution of hardness and mechanical properties of the individual analyzed sections of welded joints. The data obtained were intended to determine the extent of zones in the welded joints that have certain strength characteristics. Also conducted uniaxial tensile tests of welded joints with the registration of displacement fields on the surface of specimens by means of Aramis video-system what the final result are images of strain fields map on the surface of welded joints. The resulting strain values were compared with the results of numerical computations FEM.
Monitoring of the Production Processing in a Metallurgical Company Using FMEA Method
Authors: Dudek-Burlikowska M.
Published: December 2017

The possibility of use of Failure Mode and Effect Analysis methods is connected with continuous quality improvement of production processes in companies. Interdependence of the quality research methods and production process’s requirements have been taken into account. FMEA method is the analysis aimed at the disclosure and elimination of potential weaknesses of the process, that is the variants that may cause defects during its implementation. The example of implementing Failure Mode and Effect Analysis in polish companies have been presented.
Investigations on Wear Mechanisms of PVD Coatings on Carbides and Sialons
Authors: Staszuk M. , Pakuła D. , Pancielejko M. , Tański T. , Dobrzański L.A.
Published: December 2017

The paper presents the results on the wear resistance of PVD coatings on cutting inserts made from sintered carbide and sialon ceramics. The exploitative properties of coatings in technological cutting trials were defined in the paper, which also examined the adhesion of coatings to the substrate, the thickness of the coating, and the microhardness. As a result, it was found that isomorphic coating with AlN-h phase of covalent interatomic bonds exhibits much better adhesion to the sialon substrate than isomorphic coating with titanium nitride TiN. These coatings assure the high wear resistance of the coated tools, and the high adhesion combined with the high microhardness and fine-grained structure assure an increase in the exploitative life of the coated tools. In the case of coatings on substrate made from sintered carbide, there was a significant influence on the properties of the tools coated with them as concerns the existence of the diffusion zone between the substrate and the coating.
Corrosion Resistance of X5CrNi18-10 Stainless Steel
Authors: Kciuk M. , Lasok S.
Published: December 2017

The paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.
Environmental Degradation of Dissimilar Austenitic 316L and Duplex 2205 Stainless Steels Welded Joints
Authors: Topolska S. , Łabanowski J.
Published: December 2017

The paper describes structure and properties of dissimilar stainless steels welded joints between duplex 2205 and austenitic 316L steels. Investigations were focused on environmentally assisted cracking of welded joints. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement was determined in slow strain rate tests (SSRT) with the strain rate of 2.2 × 10−6s−1. Chloride-inducted SCC was determined in the 35% boiling water solution of MgCl2environment at 125°C. Hydrogen assisted SCC tests were performed in synthetic sea water under cathodic polarization condition. It was shown that place of the lowest resistance to chloride stress corrosion cracking is heat affected zone at duplex steel side of dissimilar joins. That phenomenon was connected with undesirable structure of HAZ comprising of large fractions of ferrite grains with acicular austenite phase. Hydrogen assisted SCC tests showed significant reduction in ductility of duplex 2205 steel while austenitic 316L steel remains almost immune to degradation processes. SSR tests of dissimilar welded joints revealed a fracture in the area of austenitic steel.
Comparison of Vacuum Sintered and Selective Laser Melted Steel AISI 316L
Authors: Brytan Z.
Published: December 2017

The paper presents the results of the basic mechanical properties determined in the static tensile test, impact un-notched Charpy test and hardness of austenitic stainless steel type 316L produced by two techniques: classical pressing and sintering in a vacuum with rapid cooling and selective laser melting (SLM). In this work fracture surface of Charpy test, samples were studied.

The results indicate that application of selective laser melting (SLM) makes it possible to double increase the strength properties of components manufactured from austenitic stainless steel type 316L compared to sintering in a vacuum. Resulted in mechanical properties strongly depend on porosity characteristic and the presence of superficial oxides in the case of sintered steel and the character of observed microstructural defects deriving from non-fully melted powder particles and the formation of voids between subsequently melted pool tracks during the SLM.
Nondestructive Testing of Ceramic Hip Joint Implants with Laser Spot Thermography
Authors: Roemer J. , Pieczonka L. , Juszczyk M. , Uhl T.
Published: December 2017

The paper presents an application of laser spot thermography for damage detection in ceramic samples with surface breaking cracks. The measurement technique is an active thermographic approach based on an external heat delivery to a test sample, by means of a laser pulse, and signal acquisition by an infrared camera. Damage detection is based on the analysis of surface temperature distribution near the exciting laser spot. The technique is nondestructive, non-contact and allows for full-field measurements. Surface breaking cracks are a very common type of damage in ceramic materials that are introduced in the manufacturing process or during the service period. This paper briefly discusses theoretical background of laser spot thermography, describes the experimental test rig and signal processing methods involved. Damage detection results obtained with laser spot thermography are compared with reference measurements obtained with vibrothermography. This is a different modality of active thermography, that has been previously proven effective for this type of damage. We demonstrate that both measurement techniques can be effectively used for damage detection and quality control applications of ceramic materials.
Necessary Thermodynamics Factors to Obtain Simple Solid Solutions in High-Entropy Alloys from the Al-Ti-Co-Ni-Fe System
Authors: Górecki K. , Bała P. , Kozieł T. , Cios G.
Published: December 2017

In this paper findings regarding the design and synthesis of High-Entropy Alloys based on mixing enthalpy, mixing entropy,δparameter, Ω parameter and valence electron concentration are presented. Four alloys were synthesised with different predicted crystalline structures. Results of the microstructure and crystal structure studies are presented. It was shown that predicted structures as well as complex intermetallic phases exist in the material. The validity of valence electron concentration as well as additional parameters such as mixing enthalpy, mixing entropy and others necessary to obtain only the solid solution in High-Entropy Alloys were examined.
The Effect of Heat Treatment on Microstructure and Mechanical Properties of Cast Bainitic Steel Used for Frogs in Railway Crossovers
Authors: Parzych S.
Published: December 2017

This work deals with the effect of heat treatment on a microstructure and mechanical properties of a selected cast steel assigned as a material used for frogs in railway crossovers. Materials used nowadays in the railway industry for frogs e.g. Hadfield cast steel (GX120Mn13) or wrougth pearlitic steel (eg. R260) do not fulfil all exploitation requirements indicated in the UIC (International Union of Railways) Decision No. 1692/96 in terms of train speed that should be reached on railways. One of the possible solution is using a cast steel with bainitic or bainitic-martensitic microstructure that allows to gain high strength properties the ultimate tensile strength (UTS) of 1400 MPa, the tensile yield strength (TYS) of 900 MPa and the hardness of up to 400 BHN. The tested material is considered as an alternative to Hadfield cast steel that is currently used for railway frogs.

Results of an experimental analysis of the effect of conducted heat treatment on a microstructure, the volume fraction of retained austenite and mechanical properties of bainitic steel, are shown in this paper. It was found that, the heat treatment leads to a stabilization of retained austenite in grain boundaries area of the primary austenite. Additionally, the heat treatment according to the variant #3 results with an almost 3-times higher impact toughness to that exhibited by material subjected to the other treatments.
Analysis of the Possibility of Calculating the Charges on the Example of Brasses
Authors: Biernat S. , Bydałek A.W. , Wołczyński W. , Najman K.
Published: December 2017

This paper describes the subject of brasses and the method of their production from the secondary raw materials. It focuses on two very important aspects extremely important for today’s world. The first of them is the theme of rational management of materials, particularly metallic scrap. The second issue is the growing importance of products made of brass, which in recent times get also special recognition in medicine. This article presents a proposal for a methodology for calculating the metal charge for brasses of two or more components. It turns out that by using suitable mathematical calculations one can accurately determine the amount of metal charge to obtain a product having the desired chemical composition and desired mechanical properties. Mathematical calculations are also presented in the graphical form for the visualization of dependency and a better explanation of the accepted approach.
The Effect of Fe-Ti Inoculation on Solidification, Structure and Mechanical Properties of High Chromium Cast Iron
Authors: Kopyciński D. , Siekaniec D. , Szczęsny A. , Guzik E. , Nowak A.
Published: December 2017

The results of studies of the effect of different amounts of the Fe-Ti inoculant on structure and selected mechanical properties of High Chromium Cast Iron (conventionally abbreviated as HCCI) are presented. The main purpose of the inoculation is structure refinement and hence the improvement of casting properties. Generally considered a strong carbide-forming element, titanium is an effective inoculant for the high chromium cast iron. However, there is an optimal amount of titanium addition beyond which the mechanical properties begin to deteriorate. The studies enabled determining the amount of Fe-Ti inoculant optimal for the cast iron of a given chemical composition.
Effect of Pressure on the Crystallisation of AlSi7Mg Alloy
Authors: Pastirčák R. , Ščury J.
Published: December 2017

This paper deals with influencing the crystallisation of Al alloys by a direct squeeze casting method. The effects of changed cooling rates of the casting is evaluated using a heat transfer coefficient at different casting conditions. The experimental results obtained by temperature measurement of the casting and the mould were used to predict the casting and mould surface temperatures using regression curves. The measured temperatures in the sub-surface layers were used to determine the amount of heat transferred from the casting to the mould. The amount of transferred heat increased 20-fold due to the effect of pressure. We also evaluated the effect of the acting pressure on the mechanical properties and microstructure of the alloy used. The process parameters were varied in the experiment.
Effect of Intensive Cooling of Alloy AZ91 with a Chromium Addition on the Microstructure and Mechanical Properties of the Casting
Authors: Rapiejko C. , Pisarek B. , Pacyniak T.
Published: December 2017

The work presents the results of the investigations of the effect of intensive cooling of alloy AZ91 with an addition of chromium on the microstructure and mechanical properties of the obtained casts. The experimental castings were made in ceramic moulds preliminarily heated to 180°C, into which alloy AZ91 with the addition was poured. Within the implementation of the research, a comparison was made of the microstructure and mechanical properties of the castings obtained in ceramic moulds cooled at room temperature and the ones intensively cooled in a cooling liquid. The kinetics and dynamics as well as the thermal effects recorded by the TDA method were compared. Metallographic tests were performed with the use of an optical microscope and the strength properties of the obtained castings were examined: UTS (Rm), elongation (A%), and HB hardness.
Fatigue Properties of Nodular Cast Iron at Low Frequency Cyclic Loading
Authors: Vaško A.
Published: December 2017

Three melts of ferrite-pearlitic nodular cast iron with different charge composition were used for fatigue tests. Wöhler fatigue curves and fatigue strength were obtained, and microstructure and fracture surfaces were investigated. The aim of the paper is to determine the influence of charge composition on microstructure, mechanical and fatigue properties of synthetic nodular cast irons and their micromechanisms of failure. Fatigue tests were realised at low frequency sinusoidal cyclic push-pull loading (stress ratio R = −1) at ambient temperature (T = 20 ±5°C). They were carried out with using the fatigue experimental machine Zwick/Roell Amsler 150HFP 5100 at frequency f ≈ 120 Hz. The results of fatigue tests at low frequency cyclic loading are compared with fatigue properties at high frequency cyclic loading.
Characteristics of Carbide Interfacial Layer Formed During Deposition of DLC Films on 316L Stainless Steel Substrate
Authors: Dudek M.
Published: December 2017

The paper presents the analysis of formation of interfacial layer during deposition of diamond like carbon film (DLC) on the 316L stainless steel by capacitive plasma discharge in the CH4atmosphere. The structure of the interfacial layer of DLC film was strongly affected by the temperature increase during the initial stages of the process. Initially, thin interfacial layer of 5 nm has been formed. As the temperature had reached 210°C, the second phase of the process was marked by the onset of carbon atoms diffusion into the steel and by the interface thickness increase. Finally, the growth of chromium carbide interface, the upward diffusion of chromium and nickel atoms to film, the etching and the decrease of the DLC film thickness were observed at 233°C. These investigations were carried out ex-situ by spectroscopic ellipsometry, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy.
Burden Optimisation of Lump Charge Materials for Foundry Furnaces
Authors: Źiółkowski E.
Published: December 2017

Calculation of economically optimum charge burden for foundry furnaces depends on a solution that can be found in the field of mathematical linear programming. A traditional linear optimisation method means looking for continuous variables that can define portion of every charge component.

Sometimes, it can be observed that a calculated portion of charge material with a defined lump mass is rounded up, which is wrong because the charge burden prepared in such a way may either show a mistaken chemical composition, or it can entail a significant cost. With charge materials characterised by defined mass lumps, it is recommended to use a modified method of integer linear optimisation.

This article contains definitions of a goal function and a system of constraints considering the charge materials as stated above. In addition, a sample calculation has been included hereto to show such optimisation for a selected process of metal melting in a casting furnace.
The Analysis of Force Parameters in Drawing Process of High Carbon Steel Wires in Conventional and Hydrodynamic Dies
Authors: Suliga M.
Published: December 2017

The paper analyzes force parameters in the process of multistage drawing of steel wires in conventional and hydrodynamic dies. The drawing process of the wire rod with a diameter of 5.5 mm for wires with a diameter of 1.70 mm was performed in 12 drafts with the usage of the multistage drawbench Koch KGT with the speed range of 5-25 m/s.

Modern software of multistage drawbenches allows direct reading of many parameters during the drawing process, including drawing power. The force and drawing stress in each drafts were determined relying on experimental measurements. A complement to the research was a theoretical analysis of the drawing process. The results of the theoretical studies were compared to those obtained by experiment.

The significant impact of the drawing speed on the force parameters of the drawing process in conventional and hydrodynamic dies was demonstrated. Depending on the real conditions of the drawing, ie. temperature, friction and lubrication, enhancing the drawing speed can result in both an increase and a decrease in drawing stress.
Effect of Processing Conditions on Forgeability and Properties of Hot and Warm-Forged Steel 300M
Authors: Skubisz P. , Łukaszek-Sołek A.
Published: December 2017

Results of investigation of the effect of processing conditions of medium-carbon alloy steel AISI 300M on forgeability and microstructure-properties are presented here, including as-forged and heat treated condition of the material. The presented results concern two vital aspects of plastic forming of high-duty impression-die forgings, which underlay a selection of technological conditions which enable the accomplishment of the required quality of the forged part. These are: firstly, the microstructure and mechanical properties and their uniformity within a part and secondly, technological realization of forging the required geometry in the given processing conditions.

In order to define a favourable processing window, dynamic behaviour modeling in variable forging conditions was carried out, establishing a coefficient of energy dissipationη% and the metal flow instability areas, which indicated the temperature regime and strain rate range for the forging process. The constructed processing maps were subject to experimental verification in the die-forging tests, carried out on a screw press. Hot and warm forging conditions were applied accordingly to selected areas of the processing maps, representative for unique forging conditions occurring in the industrial practice.
Properties and Structure of X30MnAlSi26-4-3 High Strength Steel Subjected to Dynamic Compression Processes
Authors: Śmiglewicz A. , Jabłońska M. , Moćko W. , Kowalczyk K. , Hadasik E.
Published: December 2017

The paper presents the results of investigation on X30MnAlSi26-4-3 austenitic steel subjected to dynamic compression using the split Hopkinson pressure bar. The strain rate was 3700 s−1. The compression test was also carried out without the use of breaking rings and then true strain was about 0.3. The split Hopkinson pressure bar test take only few milliseconds to complete during which time it is impossible to transfer the excess heat out of the specimen, therefore the test must be carried out in adiabatic conditions and so the increase of the temperature caused by the work of plastic deformation had to be calculated. The stepping load method was used in order to evaluate the effect of adiabatic heating on the properties of steel which allowed to maintain the isothermal deformation conditions. The paper presents the comparison of results obtained during deformation under adiabatic and isothermal conditions in correlation to structure changes occurring in course of dynamic compression.
Experimental Research on the Impact of Thin-Wall Ratio and the Fillet Radius of Forming Roller on the Limiting Spinning Ratio of AMS 5504 Sheets
Authors: Kut S. , Stachowicz F. , Ryzińska G. , Mrugała T.
Published: December 2017

Results of experimental investigations of metal spinning process of AMS 5504 sheets. cylindrical drawpieces with use of discs-shaped sheet with various diameter and thickness were shown in this work. Tests were performed on two roller metal spinning machine of a vertical axis Leifeld SFC 800 V500.

The main objective of the study was to determine the dependence between limiting spinning coefficient, thin wall ratio coefficient and the fillet radius of forming rollers. To realize this aim required the development of an original methodology and experimental research plan. Determined relationship takes into account the occurrence of negative phenomena in the process of spinning such as wrinkling or cracking of material.

Due to the possibility of prediction of these negative phenomena, determined relationship is used in the design of a metal spinning processes. On the basis on determined relationship can be done a practical assessment of the possibility of shaping with certain geometrical parameters by spinning. Obtained results were shown graphically on the diagrams and their analysis was carried.
The Development and Numerical Analysis of the Conical Radiator Extrusion Process
Authors: Michalczyk J.
Published: December 2017

The article presents a newly developed method for single-operation extrusion of conical radiators. This is the author’s radiator manufacturing method being the subject of a patent application. The proposed method enables the manufacture of radiators either with or without an inner opening and with an integral plate. Selected results of numerical computations made within Forge®3D, a finite element method (FEM)-based software program, were presented during the analysis of the process. A comparative analysis of the proposed manufacturing method using the double-sided extrusion method was also made.

The proposed manufacturing method is assumed to produce radiators in a single technological operation with the stock material being standardized 30 mm-diameter aluminium bars. The objective of the developed method is also to reduce the energy-force parameters.
Effect of Metallic Additives to Polymer Matrix on Properties of Composite Adhesives Dedicated for Light Metal Joining
Authors: Mamala A. , Kwaśniewski P. , Nowak A. , Grzebinoga J. , Ściężor W. , Kowal R.
Published: December 2017

The most recent and promising trends in development of renewable sources of energy are Combined Heat and Power (CHP) systems. The newest solutions from this field are hybrid compact solar panels. The correct operation of both systems, i.e. the photovoltaic panel and the heat exchanger requires an effective connection between the two. The adhesives utilized to interconnect above elements should provide a stable and hermetic joint able to withstand mechanical and thermal impacts of the surrounding environment factors. The paper presents the research results over the impact of the type and the amount of reinforcing phase on the physical and mechanical properties of epoxy resin matrix composites reinforced with particles of non-ferrous metals (Ag, Cu, W, Al), dedicated as adhesives for connections between photovoltaic panels and heat exchangers. Based on the experimental findings the usefulness of classical analytic models for valuation of polymer-metal composites properties was validated.
Application of Conjugate Simulation for Determination of Temperature and Stress Distributions During Curing Process of Pre-Impregnated Composite Fibers
Authors: Golewski P. , Sadowski T.
Published: December 2017

The composites made of continuous fibers in the form of unidirectional and fabric prepregs are widely used in many fields of engineering for the production of lightweight and durable parts or whole structures. To achieve this, we not only need to possess knowledge of the composite mechanics, but also have to master the technology. In most cases, particularly for parts with advanced geometric shapes, autoclaving technique is used. The success of the carried out process occurs when the prepreg reaches the proper temperature throughout its volume in the specified time, where there are no overheated or unheated zones as well as when the prepreg is correctly pressed against the mold. In order to ensure adequate stiffness, the mold has much greater thickness than formed composite and the stiffening ribs. The result is that the time required for prepreg heating is greatly extended. To prevent this, the appropriate electric heaters embedded in the silicone grips are used.

The paper presents problems related to the mold structures and application of numerical methods aiming at early verification of the temperature and stress distribution. The coupled analysis of CFD (computational fluid dynamic) and heat transfer structural simulations were performed in Abaqus program. The studies were carried out for the airfoil fragment. A total of 12 simulations were conducted, 6 cases in which heat was supplied only from air flowing through the autoclave and 6 cases which included heaters inside the silicone grips. In the result the inhomogeneity of prepreg heating for each of the mold geometry was compared, and the average temperature was obtained after 60 seconds from the process initiation. Both the pressure inside the silicone grips (before inserting the mold into the autoclave) and the non-uniform temperature distribution result in the formation of stresses whose values were analyzed for molds made of aluminum. For this purpose the temperature dependent elastic – plastic material model was used for aluminum molds.
Development of Structural Steel Containing 3÷5 wt% Al with Microlaminated Microstructure
Authors: Garbarz B. , Adamczyk M. , Niżnik-Harańczyk B.
Published: December 2017

The aim of this work was to develop basic parameters of hot rolling and controlled cooling technology allowing to obtain the microlaminated (lamellar) microstructure in a lean-alloy structural steel containing 3÷5 wt % Al. Thermo-mechanical rolling tests of two experimental steels were carried out in a semi-industrial line comprising a one – stand reversing rolling mill. The final microstructure of the specimens subjected to rolling in theγ+αstability region characterised with the microlaminated morphology composed of lamellae of ferrite with thickness down to 1 μm or less and lamellae or grains of phases developed during transformation of the austenite. Determined parameters of the thermo-mechanical processing allowed to achieve very attractive mechanical properties of the experimental steels: tensile strength over 1.0 GPa and ductility level (total elongation) better than 15%.
Microstructural Changes of the Nanostructured Bainitic Steel Induced by Quasi-Static and Dynamic Deformation
Authors: Marcisz J. , Burian W. , Rozmus R. , Janiszewski J.
Published: December 2017

Changes in the microstructure of nanostructured bainitic steel induced by quasi-static and dynamic deformation have been shown in the article. The method of deformation and strain rate have important impact on the microstructure changes especially due to strain localization. Microstructure of nanostructured steel Fe-0.6%C-1.9Mn-1.8Si-1.3Cr-0.7Mo consists of nanometer size carbide-free bainite laths and 20-30% volume fraction of retained austenite. Quasi-static and dynamic (strain rate up to 2×102s−1) compression tests were realized using Gleeble simulator. Dynamic deformation at the strain rate up to 9×103s−1was realized by the Split Hopkinson Pressure Bar method (SHPB). Moreover high energy firing tests of plates made of the nanostructured bainitic steel were carried out to produce dynamically deformed material for investigation. Adiabatic shear bands were found as a result of localization of deformation in dynamic compression tests and in firing tests. Microstructure of the bands was examined and hardness changes in the vicinity of the bands were determined. The TEM examination of the ASBs showed the change from the internal shear band structure to the matrix structure to be gradual. This study clearly resolved that the interior (core) of the band has an extremely fine grained structure with grain diameter ranging from 100 nm to 200 nm. Martensitic twins were found within the grains. No austenite and carbide reflections were detected in the diffraction patterns taken from the core of the band. Hardness of the core of the ASBs for examined variants of isothermal heat treatment was higher about 300 HV referring to steel matrix hardness.
Mechanical Properties of a Bainitic Steel Producible by Hot Rolling
Authors: Rana R. , Chen S. , Haldar A. , Das S.
Published: December 2017

A carbide-free bainitic microstructure is suitable for achieving a combination of ultra high strength and high ductility. In this work, a steel containing nominally 0.34C-2Mn-1.5Si-1Cr (wt.%) was produced via industrial hot rolling and laboratory heat treatments. The austenitization (900°C, 30 min.) and austempering (300-400°C, 3 h) treatments were done in salt bath furnaces. The austempering treatments were designed to approximately simulate the coiling step, following hot rolling and run-out-table cooling, when the bainitic transformation would take place and certain amount of austenite would be stabilized due to suppression of carbide precipitation. The microstructures and various mechanical properties (tensile properties, bendability, flangeability, and room and subzero temperature impact toughness) relevant for applications were characterized. It was found that the mechanical properties were highly dependent on the stability of the retained austenite, presence of martensite in the microstructure and the size of the microstructural constituents. The highest amount of retained austenite (~ 27 wt.%) was obtained in the sample austempered at 375°C but due to lower austenite stability and coarser overall microstructure, the sample exhibited lower tensile ductility, bendability, flangeability and impact toughness. The sample austempered at 400°C also showed poor properties due to the presence of initial martensite and coarse microstructure. The best combination of mechanical properties was achieved for the samples austempered at 325-350°C with a lower amount of retained austenite but with the highest mechanical stability.
Similarity of Ferrosilicon Submerged Arc Furnaces With Different Geometrical Parameters
Authors: Machulec B. , Gil S. , Bialik W.
Published: December 2017

In order to determine reasons of unsatisfactory production output regarding one of the 12 MVA furnaces, a comparative analysis with a furnace of higher power that showed a markedly better production output was performed. For comparison of ferrosilicon furnaces with different geometrical parameters and transformer powers, the theory of physical similarity was applied. Geometrical, electrical and thermal parameters of the reaction zones are included in the comparative analysis. For furnaces with different geometrical parameters, it is important to ensure the same temperature conditions of the reaction zones. Due to diverse mechanisms of heat generation, different criteria for determination of thermal and electrical similarity for the upper and lower reaction zones were assumed contrary to other publications. The parameter c3 (Westly) was assumed the similarity criterion for the upper furnace zones where heat is generated as a result of resistive heating while the parameter J1 (Jaccard) was assumed the similarity criterion for the lower furnace zones where heat is generated due to arc radiation.
The Attempt of the Low-Cycle Fatigue Life Description of Chosen Creep-Resistant Steels Under Mechanical and Thermal Interactions
Authors: Okrajni J. , Marek A.
Published: December 2017

The study focuses on the problem of determination of low-cycle fatigue properties for the chosen group of creep-resistant steels used in the power and chemical industries. It tries to find the parameter which would describe well the fatigue life and take into account mechanical loads and temperature. The results of LCF tests have been presented in the paper. New parameter P has been introduced. This parameter joins a plastic strain range, a stress range and temperature. The fatigue life has been predicted versus parameter P. The comparison of the predicted and observed values of fatigue life shows the agreement between these values. The method of fatigue life prediction formulated in this way is expected to describe the behavior of materials under thermo-mechanical fatigue.
Operation-Oriented Studies on Wear Properties of Surface-Hardened Alloy Cast Steels Used in Mining in the Conditions of the Combined Action of Dynamic Forces and an Abrasive Material
Authors: Wieczorek A.N.
Published: December 2017

This paper presents the results of wear tests of shot-peened and not shot-peened cast steels used in the mining machinery industry, in particular in the construction of chain drums for armoured face conveyors. Wear tests were carried out in the conditions corresponding to the real operating conditions of armoured face conveyors during drifting work in rocks such as sandstone. The operating factors subjected to the analyses included the presence of quartz abrasive and the impact of external dynamic forces. On the basis of the wear tests as well as the microhardness and microstructure examinations performed, it has been found that the action of an additional dynamic force has a synergistic impact on the process of abrasive wear in loose quartz abrasive. It has been further found that the value of abrasive wear of chain wheels operated in the conditions of a combined action of abrasive and a dynamic force depends on whether the area of mating of wheels with the chain was shot-peened or not before the wear tests – an increase in the abrasive wear was observed for the wheels made of cast steel subjected to shot peening in the area of mating with the chain. Lower resistance to abrasive wear of the cast steels subjected to shot peening before the wear tests could result from the formation of cracks in the surface layer caused by the action of shot.
Solidification Mechanism of the D-Gun Sprayed Fe-Al Particles
Authors: Wołczyński W. , Senderowski C. , Fikus B. , Panas A.J.
Published: December 2017

The detonation gas spraying method is used to study solidification of the Fe-40Al particles after the D-gun spraying and settled on the water surface. The solidification is divided into two stages. First, the particle solid shell forms during the particle contact with the surrounding air / gas. Usually, the remaining liquid particle core is dispersed into many droplets of different diameter. A single Fe-Al particle is described as a body subjected to a rotation and finally to a centrifugal force leading to segregation of iron and aluminum. The mentioned liquid droplets are treated as some spheres rotated freely / chaotically inside the solid shell of the particle and also are subjected to the centrifugal force. The centrifugal force, and first of all, the impact of the particles onto the water surface promote a tendency for making punctures in the particles shell. The droplets try to desert / abandon the mother-particles through these punctures. Some experimental evidences for this phenomenon are delivered. It is concluded that the intensity of the mentioned phenomenon depends on a given droplet momentum. The droplets solidify rapidly during their settlement onto the water surface at the second stage of the process under consideration. A model for the solidification mechanism is delivered.
Assessment of Aluminum FSW Joints Using Ultrasonic Testing
Authors: Adamus K. , Lacki P.
Published: December 2017

The paper concerns aluminum joints made using friction stir welding. Although in the aerospace industry there is a tendency to replace metal components with composites, aluminum continues to be a valuable material. Its share in the aircraft structures is the biggest among all structural metals. Lots of aluminum components are made of sheets and most of them require joining. Friction stir welding is a relatively new joining technology, particularly with regard to the sheets having a thickness of 1 mm or lower. The paper is dedicated to non-destructive testing of such joints using ultrasonic inspection. It was found that ultrasonic testing allows for distinguishing between joints without material discontinuities, joint with material discontinuities at the advancing side and joint with discontinuities extending through the whole width of the stir zone. During research only horizontally aligned defects were taken into account.
Composite Coatings of Chromium and Nanodiamond Particles on Steel
Authors: Gidikova N. , Sulowski M. , Petkov V. , Valov R. , Cempura G.
Published: December 2017

Chrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.
Microstructural Evolution During Laser Surface Alloying of Ductile Cast Iron with Titanium
Authors: Janicki D.
Published: December 2017

Diode laser surface alloying process was used to the in-situ synthesis of TiC-reinforced composite surface layers on the ductile cast iron substrate. The obtained composite surface layers were investigated using optical and scanning electron microscopy, and XRD diffraction.

It was found that the morphology and fraction of TiC phase is directly dependent upon both the concentration of titanium in the molten pool and also the solidification rate. With increasing titanium content, the fraction of TiC increases, whereas the fraction of cementite decreases. The TiC phase promotes a heterogeneous nucleation of primary austenite grains, what reduces a tendency of cracking in the alloyed layers.
Thermal Assessment of Modified Ultra-Light Magnesium-Lithium Alloys
Authors: Król M. , Mikuszewski T. , Kuc D. , Tański T. , Hadasik E.
Published: December 2017

The paper presents the results of the influence of commercial TiBor and AlSr10 master alloys on the refine the grains size, hardness and crystallisation process based on the thermal-derivation analysis of light cast magnesium-lithium-aluminium alloys. The effects of TiBor and AlSr10 content on the characteristic parameters of the crystallisation process of Mg-Li-Al alloys were investigated by thermal-derivative analysis (TDA). Microstructural evaluations were identified by light microscope, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy.

The results showed that the addition of TiBor master alloy reduced the grain size of Mg-9Li-1.5Al cast alloy from 900 μm to 500 μm, while the addition of AlSr10 master alloy reduced the grain size of investigated cast alloy from 900 μm to 480 μm. Moreover, an addition of TiBor and AlSr10 simultaneously reduced the grain size from 900 μm to 430 μm.

Results from the thermal-derivative analysis showed that the addition of grain refinement causes a decrease in nucleation temperature and solidus temperature.
Investigations on the Process of Lead Removal from Cu-Pb Alloys During their Melting in Vacuum Induction Furnace
Authors: Siwiec G. , Buliński P. , Palacz M. , Smołka J. , Blacha L.
Published: December 2017

The paper presents analysis and assessment of operating power of vacuum induction furnace in relation to the efficiency of lead removal from Cu-Pb alloy in VIM (vacuum induction melting) technology. Thermodynamic analysis of the process is performed as well.