The effect of temperature, in the range 750 deg C - 1500 deg C, on the flow stress of polycrystalline diamond

摘要

Earlier work has shown that the soft impressor method can be used to measure the flow stress of single crystal diamond as a function of temperature providing results which very clearly distinguish between the various types of diamond and the effect of nitrogen impurities. High dislocation mobility, multiple intersecting slip and impression creep all occur above a specific (Brittle-Ductile) transition temperature for a given type of diamond - e.g. 750 deg and 9000 deg C for synthetic type Ib and natural type Ia respectively.