This research investigated the influence of silicon dioxide (SiO2) with particle size of 5 micron on microstructure, mechanical properties and wear resistance of UHMWPE polymeric composite materials under dry sliding friction that was tested by Block–on–ring technique according to ASTM G77. Bulk UHMWPE composite specimen was reinforced with SiO2 particles by weight fraction of 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4 and 5 wt.%. Specimen was performed by hot compression process with the compression forming conditions at the temperature of 202°C, pressure of 9.7 MPa and exposure time of 77 minutes. It was found that, SiO2 particle fraction in the range of not exceed than 0.5 wt.% did not affect to change microstructure of the specimen, which its microstructure did not significantly different from the initial UHMWPE specimen due to SiO2 particles were dispersed uniformly in the UHMWPE matrix. Its microstructure appeared in a spherulitic structure pattern. However, the increasing of SiO2 more than 0.5 wt.% affect to changed microstructure due to the SiO2 particles separated from the matrix and accumulated on the UHMWPE matrix. For the case of mechanical and wear resistance properties, the increasing of SiO2 particle of 0.5-1 wt.% affect to increased various mechanical properties to have a highest value and lowest wear rate as compared with initial UHMWPE up to 1.7 times. After that, the increasing of SiO2 particle affect to mechanical properties and wear resistance were decreased, except for the hardness that continuously increased according to the increasing of SiO2.

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The tribotechnical properties of ultra-high molecular weight polyethylene (UHMWPE) based composite filled with hydroxyapatite (HA) microparticles under dry sliding and lubrication of distilled water and plasma blood wear investigated with block-on-ring. It was shown that modification of UHMWPE by HA microparticles of 20 wt.% results in decrease of wear intensity at dry sliding up to 4 times. The under lubrication, wear intensity of pure UHMWPE and microcomposite are deceased up to 50–70% as compared with under dry sliding. Permolecular structure of pure UHMWPE and microcomposite are spherulitic structure and the HA microparticles were dispersed in the UHMWPE matrix.

The tribotechnical properties of hydroxyapatite (HA) nanocomposite based on ultra-high molecular weight polyethylene (UHMWPE) under dry sliding and lubrication of distilled water and plasma blood was investigated with block-on-ring. It was shown that modification of UHMWPE by HA nanoparticles within range of 0.1–0.5 wt.% results in decrease of wear intensity at dry sliding up to 3 times. The under lubrication, wear intensity of pure UHMWPE and nanocomposite are deceased up to 50–70% as compared with under dry sliding. Permolecular structure of pure UHMWPE and nanocomposite are spherulitic structure, which nanoparticle does not alter the nature of the permolecular structure, and homogeneously dispersed in the UHMWPE matrix.

This paper studies the influence of work conditions, difference compression load and counterface roughness, on UHMWPE under abrasive wear test without lubrication according to GOST 426-77. It was found that the formation of deep and wide furrows on worn surface and abrasive intensity increased when the number of grit grade was decreased (average grit size increase). The behavior of abrasive wear can be classified as follows: the first characteristic volume loss quickly increases in the beginning of running time about 5-15 minutes, which is referred to as “run-in” wearing stage; the second characteristic volume loss regularly increases after running time about 15 minutes, which is approaching to “steady-state” wearing stage. In addition, the abrasive wear intensity increase with increasing compression load and/or decreasing number of grit grade (average grit size increase). The results of this research can be applied to abrasive applications in mechanical engineering.