MEASUREMENT OF HARDNESS USING A SEMICONDUCTOR DIAMOND INDENTOR

Authors have now been able to obtain an indentor made from a semiconducting (type IIb) diamond. Paper reports the results of the measurements that were made using this new indentor. There are indications that the electrical properties of diamond were far from uniform but it will be shown that such non-uniformity can be turned to advantage if a new loading procedure is adopted. It is concluded that the hardness of metals can be estimated from resistance measurements using a semiconducting diamond indentor. A pre-test capacitor discharge, as previously described for a silicon carbide indentor, is advantageous. It has been shown that non-uniformity in the electrical properties of the diamond can actually be utilized provided the load on the indentor is continuously varied rather than pre-determined.