Defect prevention in powder metallurgy components

Cracking in Powder Metallurgy (P/M) is one of the critical concerns in the P/M industry. A general knowledge base and guidelines for crack prevention in green P/M compacts for conventional rigid die P/M compaction has been developed which includes the causes of cracks, tooling deflection, crack classification, and crack prevention issues.; Specific areas of development described in this dissertation include; (1) An investigation and study of the fundamental P/M compaction mechanisms that are responsible for crack issues, from microstructure to dynamic analysis. (2) Establishment of a knowledge base for causes of cracks including the definition of common causes by 32 cracking mechanisms, and recommendations to avoid these cracks. (3) A detailed study of tooling deflection including; analysis of the individual tooling elements deflection, the causes of cracks by tooling deflection, and the methods to avoid deflection cracks. (4) A classification system to group cracking characteristics by cracking location, direction, cracking path and in process characters which can define the causes of cracking by knowing the characteristics. (5) A general knowledge base to guide engineers to avoid and/or prevent cracking from the part design, tooling design, tooling and machine setup, part handling and material composition aspects.; This dissertation provides a resource that allows engineers to enhance their performance in the quality and cost area by reducing and/or eliminating cracks in the green P/M compacts, and provides both short term and long range benefits to the P/M industry.