Fracture Toughness Measurements of Powder Metallurgical (P/M) Green Compacts

摘要

The fracture toughness testing of green powder compacts is significantly more problematic than the testing of most other brittle materials, such as ceramics, and cannot be approached by conventional means. We propose in this paper a simple method of introducing a sharp V-type notch into green compacts without inducing any mechanical damage or residual stresses to the locality of the notch tip. The resultant notch is extremely sharp with a root radius in the order of 2-3 μm. In this study both conventionally pressed and warm compacted iron-based powders were used to validate the applicability of the notching method to the fracture toughness testing of green compacts. Results indicate that the method is sensitive enough to discern trends in the fracture toughness for these materials and provides data with a high level of reliability and consistency.