Influence of SiO_2 Micro-Particles on Microstructure, Mechanical Properties and Wear Resistance of UHMWPE Based Composite under Dry Sliding Friction

摘要

This research investigated the influence of silicon dioxide (SiO_2) 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 SiO_2particles 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, SiO_2 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 SiO_2 particles were dispersed uniformly in the UHMWPE matrix. Its microstructure appeared in a spherulitic structure pattern. However, the increasing of SiO_2 more than 0.5 wt.% affect to changed microstructure due to the SiO_2 particles separated from the matrix and accumulated on the UHMWPE matrix. For the case of mechanical and wear resistance properties, the increasing of SiO_2 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 1.7Times. After that, the increasing of SiO_2 particle affect to mechanical properties and wear resistance were decreased, except for the hardness that continuously increased according to the increasing of SiO_2.