Characterization of Consolidation of Non-Spherical Powders

We propose to characterize the early stage of consolidation of non-spherical powders to further the development of process models to enable simulation of powder metallurgy manufacturing for the consumer market, especially the automotive industry. Typically, spherical powders with a narrow size distribution are used for aerospace applications, while low-cost powders with irregular shapes and a wide powder size distribution are used for the consumer market. Ashby and colleagues have developed models for powder consolidation which rely on an assumed ideal packing of spherical monosized particles, with a uniform initial relative density around 0.64. For low-cost, irregular shape powders, the initial relative density is low (typically around 0.40) and varies within a component. It is the ultimate objective to expand the applicability of existing consolidation models which have proved extremely useful for net shape forming in the aerospace industry. The objectives of Phase 1 are (1) full characterization of die filling operation and identification of potential improvements; and (2) characterization of powder compaction/rearrangement for non-spherical particles and identification of critical parameters for use as model inputs. The results can be used to develop a complete set of experimentally validated models to simulate compaction of non-spherical powders.