Analysis of ASTM399 Fracture Toughness Testing of Diamond Impregnated Co Matrix

摘要

The determination of mechanical properties of diamond impregnated metal matrices(DIMMs) is very important if proper understanding of the relationship between diamond tool and the workpiece is to be achieved. The wear of the workpiece and diamond tool is paramount for proper tool performance. An important mechanical property of a diamond tool is its fracture toughness because it can be used in predicting wear analysis.However, fracture toughness determination of DIMMs is rarely carried out for a number of reasons, e.g. specimen preparation and difficulty of test method. This paper covers two methods, one method adhering to the fracture toughness ASTM standard E399 and the other a simpler variant of the standard. The effects of diamond size and concentration on the plane strain fracture toughness of PM cobalt have been investigated. Both the test methods used and the fracture toughness results are analysed using statistical methods with emphasis on the Weibull weakest link method.