Dry sliding behavior of transparent yttrium aluminum garnet against 100Cr6 steel balls

Transparent yttrium aluminum garnet (YAG) exhibits high hardness and abrasive resistance, making it a promising candidate for applications involving material contact, such as protective optical elements, windows, domes, and armors. When transparent YAG is employed in such applications, it may be susceptible to degradation due to friction, chemical exposure, or thermal stress. Despite its potential, there is limited research on the tribological behavior of transparent YAG. In the present study, transparent YAG ceramics were fabricated by reaction sintering of high-purity Al2O3 and Y2O3 powders. The transparent YAG specimens had an average grain size of 20 ± 6 µm and hardness of 1068.98 ± 115.15 HV, and fracture toughness of 1.27 ± .06 MPa.m0.5. The effect of load variation from 5 to 15 N on the tribological behavior of transparent YAG was investigated when slid against chrome steel (100Cr6) balls with a hardness of 815 ± 75 HV. The low coefficient of friction (COF) and wear rate were observed due to the wedge formation (fish-scale-like pattern) at the surface when the load was increased from 5 to 10 N. Moreover, tribochemical layer formation, fracture, and material transfer were observed when the load was increased from 10 to 15 N, leading to high COF and increased wear rate.