bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of Eutectic Formation in Al-Si Alloy Using A Phase-Field Method
Authors: Ebrahimi Z. 
Published: December 2017

AbstractWe have utilized a phase-field model to investigate the evolution of eutectic silicon in Al-Si alloy. The interfacial fluctuations are included into a phase-field model of two-phase solidification, as stochastic noise terms and their dominant role in eutectic silicon formation is discussed. We have observed that silicon spherical particles nucleate on the foundation of primary aluminum phase and their nucleation continues on concentric rings, through the Al matrix. The nucleation of silicon particles is attributed to the inclusion of fluctuations into the phase-field equations. The simulation results have shown needle-like, fish-bone like and flakes of silicon phase by adjusting the noise coefficients to larger values. Moreover, the role of primary Al phase on nucleation of silicon particles in Al-Si alloy is elaborated. We have found that the addition of fluctuations plays the role of modifiers in our simulations and is essential for phase-field modeling of eutectic growth in Al-Si system. The simulated finger-like Al phases and spherical Si particles are very similar to those of experimental eutectic growth in modified Al-Si alloy.
Vibration-Assisted Laser Surface Texturing and Electromachining for the Intensification of Boiling Heat Transfer in a Minichannel
Authors: Piasecka M. , Strąk K. , Grabas B. 
Published: December 2017

AbstractThe paper describes applications of the vibration-assisted laser surface texturing and spark erosion process as methods of modifying properties and structures of metal surfaces. Practical aspects of the use of produced surfaces in the heat exchanger with a minichannel have been described. Compared with smooth surfaces, developed metal surfaces obtained by vibration-assisted laser surface texturing and electromachining show more effective heat transfer. The local heat transfer coefficient for the saturated boiling region obtained for developed surfaces had the values significantly higher than those obtained for the smooth plate at the same heat flux. The experimental results are presented as the heated plate temperature (obtained from infrared thermography) and relationships between the heat transfer coefficient and the distance along the length of the minichannel for the saturated boiling region.
Experimental and Finite Element Analysis of Asymmetric Rolling of 6061 Aluminum Alloy Using Two-Scale Elasto-Plastic Constitutive Relation
Authors: Wronski M. , Wierzbanowski K. , Wronski S. , Bacroix B. , Lipinski P. 
Published: December 2017

AbstractThe goal of this work was theoretical and experimental study of micro- and macroscopic mechanical fields of 6061 aluminum alloy induced by the asymmetric rolling process. Two-scale constitutive law was used by implementing an elasto-plastic self-consistent scheme into the Finite Element code (ABAQUS/Explicit). The model was applied to study the asymmetric rolling. Such a deformation process induces heterogeneous mechanical fields that were reproduced by the model thanks to the crystallographic nature of constitutive law used. The studied material was processed, at room temperature, in one rolling pass to 36% reduction. The resulting material modifications were compared with predictions of the two-scale model. Namely, the calculated textures were compared with experimental ones determined by X-ray diffraction. Especially, detailed quantitative analysis of texture variation across the sample thickness was done. The influence of this texture variation on plastic anisotropy was studied. The advantages of asymmetric rolling process over symmetric one were identified. The main benefits are a nearly homogeneous crystallographic texture, reduced rolling normal forces and homogenization of plastic anisotropy through the sample thickness.
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

AbstractThe 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

AbstractIn 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

AbstractDynamic 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

AbstractIn 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

AbstractThis 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

Abstract
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

Abstract
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

Abstract
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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractIn 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

Abstract
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

Abstract
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

AbstractThe 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

AbstractThis 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.