Microstructure properties of particles reinforced polytetrafluoroethylene composite bearings after wear

High-performance engineering polymers that ensure the desired properties for journal bearings and give good wear results are investigated. In this study, microstructure properties of polymer-based particle reinforced PTFE composite bearings have been determined by optical and SEM wear surface images.Вивчено спеціальні полімери підвищеної довговічності, які можуть забезпечити бажані властивості для буксових підшипників, зокрема, зносотривкість. За допомогою оптичної та електронної мікроскопії досліджено мікроструктурні властивості матеріалів на політетрафторетиленовій основі після зношування.Изучены специальные полимеры повышенной долговечности, которые могут обеспечить желаемые свойства для буксовых подшипников, в частности, износостойкость. С помощью оптической и электронной микроскопии исследованы микроструктурные свойства материалов на политетрафторэтиленовой основе после износа

JOURNAL OF MATERIALS PROCESSING TECHNOLOGY

This paper examines the element diffusions that take place in material when SAE 1040-WC materials are connected by brazing. During the brazing process, oxyacetylene fire was used and connected parts were cooled in air. On the connection zone, microhardness measurements and microprobe analyses were made. The hardness distribution in microhardness measurements on this zone shows the existence of element diffusion. Having performed line and surface micro probe analyses of various zones, postbrazing diffusions of Co and Ni elements were determined. (c) 2005 Published by Elsevier B.V

BULLETIN OF MATERIALS SCIENCE

In this study, different welding parameters were applied to two different steels with high alloys and mechanical and metallographical investigations are performed. Thus, the optimum welding parameters were determined for these materials and working conditions. 12.30 diameter steel bars made up of 1.4871 (X53CrMnNiN219) and 1.4718 (X45CrSi93) steel were used as experimental material. The material loss increased with increase in friction and rotating pressure. No fracture at the welding region was observed and the highest fracture energy was identified in B5 group. Based on micro hardness investigation; the hardness profile reached its minimum value at the welding region

MATERIALI IN TEHNOLOGIJE

In this study, the abrasive wear behaviour of aluminium-alloy (Al-2011) SiC-particle-reinforced composites was investigated and compared with that of the matrix alloy. The experimental variables were the SiC-particle proportion, sliding distance and abrasive grit size. Al-2011 reinforced composites containing volume fractions (7, 14 and 21) % SiCp were fabricated with the vortex method. Sliding-wear tests were carried out using a pin-on-disc abrasive-test machine where a sample slides against a SiC abrasive of different grit sizes at a fixed speed, under the load of 4 N at room conditions. The results show that the wear resistance of the composites was significantly larger than that of the Al-2011 alloy; it increased with the increasing SiC-particle proportion and decreased with the increasing abrasive grit size

MATERIALS TESTING

In this study, high alloyed steel bars with a diameter of 12.30 mm made up of 1.4871 (X53CrMnNiN219) and 1.4718 (X45CrSi93) steels were used as experimental material for friction welding. Metallographic and X-ray diffraction investigations as well as microprobe sampling were performed on the samples. Mechanical orientation of particles caused by plastic deformation and carbide scattering has been observed. The diffusion behaviour has been investigated for the elements Cr, Ni, Mn, and Si, respectively. The existence of (Cr,Fe)(7)C-3 carbides in the welding region was also observed