Wojciech Borek | Silesian University of Technology (original) (raw)

Papers by Wojciech Borek

Journal of Thermal Analysis and Calorimetry, 2014

Archives of Materials Science and Engineering

Purpose: The aim of the paper is to compare results after thermo-mechanical simulation using Glee... more Purpose: The aim of the paper is to compare results after thermo-mechanical simulation using Gleeble 3800 and hot-rolling on LPS module of high-manganese austenitic X11MnSiAl7-1-3 steel. Design/methodology/approach: The hot-working behaviour was determined in continuous, 4-and 8-stage compression tests performed in a temperature range of 850 to 1100°C by the use of the Gleeble 3800 thermo-mechanical simulator and LPS module for semi-industrial hot rolling. The comparison between two processes has been established based on microstructure research and X-ray diffraction analysis. Findings: It was found that austenite microstructure with numerous annealing twins in the initial state was obtained. 4-stage compression tests were realized in the temperature range from 850 to 1050°C with the true strain 4x0.23. 8-stage compression test were performed in the same temperature range and with true strain of 0.4 in the first deformation, and 0.25 and 0.2 in the following deformations. The multi-...

Advanced Structured Materials, 2015

Advanced Materials Research, 2014

Since many year there are carried out investigations concerning the appliance of high power diode... more Since many year there are carried out investigations concerning the appliance of high power diode laser (HPDL) for surface treatment of engineering materials, including light alloys (AlSi9Cu2 aluminium cast alloy), copper, as well as diverse steel types. This paper presents the results of laser remelting influence on structure and properties of the surface of the X40CrMoV5-1 and 32CrMoV12-28 hot work tool steels, carried out using HPDL, as an possible extension of this useful technique, applied successfully for aluminium cast alloys surface treatment. Structure changes were determined in the work, as well as investigations were performed concerning the wear resistance and hardness of the different remelting areas. The reason of this work was to achieve a good layer hardness and wear resistance for protection of this tool materials from losing their work stability and to make the material surface more resistant for work extreme conditions. The goal of this work was to determine technical and technological conditions for remelting the surface layer with HPDL.

Materials Science Forum, 2005

Page 1. Influence of thermo-mechanical treatments on the stored energy simulated by FEM for two l... more Page 1. Influence of thermo-mechanical treatments on the stored energy simulated by FEM for two low carbon steels. T. Baudin1a, AL Etter1b, P. Gerber1,3c, A. Samet1d, R. Penelle1e and C. Rey2f 1Université de Paris Sud, ICMMO ...

Chinese Journal of Mechanical Engineering, 2001

Biomaterials, 2004

Isolated enamel defects are commonly seen in first permanent molar teeth but there has been littl... more Isolated enamel defects are commonly seen in first permanent molar teeth but there has been little work on the physical and morphological composition of affected molars. The aim of this study was to determine the mechanical and morphological properties of hypomineralised first permanent molar teeth, utilising the Ultra-Micro-Indentation System (UMIS) and scanning electron microscope, respectively. Further investigations using Energy Dispersive X-ray Spectrometery (EDS), Back Scatter Electron (BSE) Imaging, and Xray diffraction were employed to attempt to determine the chemical composition, mineral content and crystalline structure of the hypomineralised tissue, respectively, of eight first permanent molars with severe enamel hypomineralisation. The hardness and modulus of elasticity were found to be statistically significantly lower (0.5370.31 and 14.4977.56 GPa, respectively) than normal enamel (3.6670.75 and 75.5779.98 GPa, respectively). Although the fractured surface of the hypomineralised enamel was significantly more disorganised and the relative mineral content was reduced by approximately 5% in comparison to sound enamel, the mineral phase and Ca/P ratio was similar in hypomineralised and sound enamel. The dramatic reduction in the mechanical properties of first permanent molar teeth has ramifications when clinicians are choosing restorative materials to restore the defects. The reason for the dramatic reduction in mechanical properties of hypomineralised first permanent molar teeth is at present unknown. r

Australian Journal of Multi-Disciplinary Engineering, 2013

Archives of Civil and Mechanical Engineering, 2012

Thermo-mechanical treatment TRIP/TWIP steels Stress-strain curve Recrystallization a b s t r a c ... more Thermo-mechanical treatment TRIP/TWIP steels Stress-strain curve Recrystallization a b s t r a c t Recent development in group of Fe-Mn-Al-Si steels with high-manganese content demands for more research in thermo-mechanical treatment and development of microstructure in such steels. Hot working conditions on forming the structure and course of the heat activated processes, removing the strain hardening effects, have been investigated.

Archives of Civil and Mechanical Engineering, 2008

The high-manganese austenitic steels are an answer for new demands of automotive industry concern... more The high-manganese austenitic steels are an answer for new demands of automotive industry concerning the safety of passengers by the use of materials absorbing high values of energy during collisions. The chemical compositions of two high-manganese austenitic steels containing various Al and Si concentrations were developed. Additionally, the steels were microalloyed by Nb and Ti in order to control the grain growth under hot-working conditions. The influence of hot-working conditions on recrystallization behaviour was investigated. On the basis of initial investigations realized by hot upsetting the thermo-mechanical conditions resulting in a fine-grained structure were designed. The σ -ε curves and identification of thermally activated processes controlling work-hardening by the use of the Gleeble simulator were determined. It was found that the thermo-mechanical treatment conditions influence a phase composition of the investigated steels after solution heat treatment.