超微粒子超硬合金の坑折力に及ぼす試験片寸法ならびに形状効果に関する一考察

抄録

In order to investigate the effects of the specimen size and the shape on the transverse-rupture strength of a cemented carbide, bending tests were carried out using two kinds of specimens (a square specimen and a round specimen). In the square specimen, the transverse-rupture strength was nearly constant regardless of the specimen width. On the other hand, in the round specimen, the transverse-rupture strength increased with increasing specimen diameter. And the transverse-rupture strength of the round specimen was larger than that of the square specimen. It was clarified that the above-mentioned effects of the specimen size and shape on the transverse-rupture strength of a cemented carbide were caused by the following three factors : 1) the distribution of the defects in the specimen, 2) the 3-dimensional stress distribution in the specimen, and 3) the critical condition of the specimen rupture.