抄録
Two types of sliding contact between a hard indenter and a brittle material were presently adopted: one is a conventional type and the other a grinding type. A fraction of heat flowing into the material in the grinding type was theoretically shown to be described by a function of a Peclet number and to be almost the same as that in the conventional type under the normal grinding conditions.
The critical indenter radius, Rc, which distinguishes the occurence of plastic deformation from the elastic cracking as the first damaging event in the material, was analyzed under the mechanical/thermal load conditions.
Increase in Rc with an increase in sliding speed V was very high in Al2O3 because of low thermal diffusivity κ, high thermal conductivity K and high thermal constant M=αE/{π(1+ν)ρC} (where, α: coefficient of expansion, E: Young's modulus, ν: Poisson's ratio, ρ: density, C: specific heat). While a similar relation between Rc and V was also found in Si3N4, the increase in Rc with an increase in V was small in glass and SiC because of low K and high κ, respectively.
