Patent ID: 7799427
Filing Date: 2010-09-21
Classification: C30B,Y10T

Abstract:
1. A body of single crystal diamond produced by CVD for use in a wear application, wherein the wear rate of a wear surface of the diamond is no greater than 0.11 μm/min when measured by processing the diamond into at least five sinter-mounted wire drawing dies with a minimum hole diameter in the range of 80 μm, specified to within 0.15 μm diameter and with an ovality of less than 0.1 μm, and with a reduction angle of 10-12°, and then with a Heinrich HZ10 machine drawing stainless steel wire DIN 1.4301 through each die with wet drawing with a mineral oil coolant and a drawing speed 10 m/s, and measuring the diameter and ovality of the wire at the beginning of the test and at various times with a Zumbach ODAC 16J laser diameter measuring system, and then obtaining an average wear rate for the at least five wire drawing dies, wherein the body of single crystal diamond has a nitrogen concentration, in the form of the single substitutional nitrogen centre as measured by EPR, with a lower concentration limit of 2×10