Two material powder injection molding (PIM) is a recently developed method to manufacture functionally graded components. This paper describes an experimental technique to determine the suitability of two materials to be combined via PIM. This is accomplished by comparing the individual shrinkage versus temperature behavior of the candidate systems. The concepts are validated by two material PIM, sintering, and subsequent microstructural observation. Two materials are compatible for two material powder injection molding provided they form a metallurgical bond and the sintering response of one material mimics the other. An extensive difference in sintering shrinkage, especially during the initial stage of sintering, results in defects such as cracks and delamination. Success of these concepts is elucidated by two material PIM of tool steel and boron doped austenitic stainless steel. (C) 2003 Kluwer Academic Publishers.