The effect of crystal and order-disorder transformations on friction and wear for Be-Co and FeCo alloys were studied in sliding friction experiments in vacuum at elevated temperatures. The results show that friction increases fourfold for the beryllium-cobalt alloy during transformation and that friction remains high until the reverse or cooling transformation occurs. The friction and wear of Be-Co are markedly superior to 440-C stainless steel. The order-disorder transformation in FeCo increases friction by a factor of 30 and also significantly increases wear. Increased sliding speed and loading affect the transformation. The friction behavior during heating is in good agreement with the type of order-temperature relation in FeCo.

Sliding friction and wear experiments were conducted with ternary ordered alloys of iron and cobalt containing various amounts of silicon to 5 weight percent. The friction and wear of these alloys were compared to those for binary iron-cobalt alloys in the ordered and disordered states and to those for the conventionally used bearing material, 440-C. Environments in which experiments were conducted included air, argon, and 0.25percent stearic acid in hexadecane. Results indicate that a ternary iron - cobalt - 5-percent-silicon alloy exhibits lower friction and wear than the simple binary iron-cobalt alloy. It exhibits lower wear than 440-C in all three environments. Friction was lower for the alloy in argon than in air. Auger analysis of the surface of the ternary alloy indicated segregation of silicon at the surface as a result of sliding.

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