金刚石在切磨过程中的损伤及相应的处理方法

金刚石在切磨过程中可能会出现机械损伤和热化学损伤.出现机械损伤的原因,除人为操作不当外,主要与高温下金刚石因存在内应力而产生的机械破裂有关.有内应力的金刚石在正交偏光镜下呈现异常双折射现象,可以在正交偏光镜下对金刚石进行分选,将内应力大的金刚石挑出,以便在切磨时进行特殊的处理.热化学损伤产生的原因是在研磨过程中产生的高温使金刚石表层因燃烧而气化,局部缺氧的部位石墨化.在研磨前将金刚石先浸入硼砂过饱和溶液中,再进行研磨,可以有效地防止热化学损伤的发生.

Damage to Diamond During Cutting and Its Solutions

The thermal or mechanical damage to diamond occurs possibly during the various stages of cutting and polishing. The mechanical damage to diamond is related to the internal stress-induced fissure under the high temperature. The different styles of anomalous birefringence can be observed in diamond with internal strain. Those diamonds can be picked out under the polarized microscopy so that they are cut specially. During the stages of cutting and polishing, heat accumulation can lead to burn marks on the surface of diamond. This kind of thermal damage can be prevented by using supersaturated solution of borax in the process of diamond cutting.