Tribological properties of ceramics evaluated at low sliding speeds

not registered; Kano, Shigeki

Low speed tribological properties of stainless steel, ceramics and hard metals were investigated in air at room temperature and in nitrogen atmosphere at high temperature for the consideration of sliding type support structure in intermediate heat exchanger of fast reactor. The following results are obtained. (1)In low speed friction measurements in air at room temperature, friction coefficients of ceramics and hard metals were smaller than that of stainless steel. Surface roughness of the specimens increased the friction force and silicon carbide showed the smallest friction coefficient among the specimens with mirror polished surface. (2)From the results of friction measurements at various sliding speeds in air at room temperature, friction coefficients of ceramics and hard metals were always stable and lower than that of stainless steel. Among ceramics, PSZ showed the smallest friction and silicon carbide showed the most stable friction at any sliding speeds. (3)Friction coefficients of silicon carbide and silicon nitride in nitrogen atmosphere at high temperature showed low values as measured at room temperature. On the contrary, friction coefficient of stainless steel measured in nitrogen atmosphere at high temperature were higher than that measured at room temperature, over 1. (4)In the reciprocal sliding tests in nitrogen atmosphere at high temperature, friction coefficient of stainless steel were over 1. On the contrary, the friction coefficients of ceramics were less than 1 instead of chipping during the slidings.