1991 年 38 巻 5 号 p. 614-620
Recently the particle analysis of hard materials with complex phases, such as cemented carbides and Mo2FeB2 base hard alloys, has been performed by using an image analyzer. But a conventional algorithm of the image analysis has some difficulties to get accurate measurements of the microstuructural parameters, such as a mean particle size, contiguity and aspect ratio of hard partcles. To solve this problem, a new algorithm for grain boundary detection has been developed by using a back-scattered electron image, which shows electron channeling contrast (ECC) depending on the crystal direction difference in the aggregated hard particles. By applying this method to the Mo2FeB2 base hard alloys, it is quantitatively elucidated that the transverse rupture strength (TRS) drop at lower sintering temperature is due mainly to the coalescence of the hard particles.