Wear and friction of Y-TZP spheres reciprocating against various Sialon plates

The friction and wear characteristics of various Y2O3-stabilized tetragonal ZrO2 polycrystal (Y-TZP)-Sialon sliding systems were examd. These systems consisted of a Y-TZP sphere reciprocating against various Sialon plates. The Sialons differed in phase content and compn. They range from a-Sialons to b-Sialons and include a-b composites. The length of the wear tracks was 10 mm, the loads used were 2 and 8 N, the frequencies 1, 4 and 8 Hz and the humidity was controlled by flushing with dry nitrogen. The tests were continued for 8, 24 and 72 h at room temp. The total vertical displacement and the friction coeff. were measured continuously and sampled. Various addnl. measurements were performed after each test and the worn surfaces were obsd. microscopically. It was concluded that the a-b composites show less wear than the single-phase a- and b-Sialons. It was also concluded that the amt. of wear increases approx. linearly with increasing load and increases significantly more than linearly with increasing frequency. A wear mechanism was derived incorporating the measured data and the observations. [on SciFinder (R)]