第三节超硬磨料的评价与选用1晶形，定量，值人造金刚石一般生长成六-八面体，根据（111）和（100）面的不同发育程度，可以引入定量描述金刚石晶体形态的定量指标r值，其定义为：τ＝b／a式中a是轮廓立方体（100）面对角线长度的一半，b是（111）与（100）面交线到（10）面对? Section III Evaluation and Selection of Superhard Abrasives 1 Crystal form, quantitative, value Synthetic diamond generally grows into hexa-octahedron. According to the different degrees of development of (111) and (100) planes, quantitative indicators describing the morphology of diamond crystals r, which is defined as: τ = b / a where a is half the length of the diagonal of the contour cube (100) and b is the intersection of (111) and (100)