PNNL

Abstract

With recent advances in synthesizing titanium powder by low-cost routes, there has been growing interest in identifying process/material conditions that overcome the powder compaction problems typically found with this reactive metal. The use of instrumented dies in studying the cold pressing process for commercial iron and steel powders has provided greater insight into the complex phenomena that occur and may be used to evaluate constitutive relations that describe the compaction process. Nevertheless, little work has been conducted on the special, more problematic case of reactive metal powders such as titanium. An instrumented die was developed that allows die wall friction to be characterized and the radial stress distribution along the die wall and throughout the compact to be monitored. As will be presented, this tool has been used to investigate titanium compaction and to draw comparisons with results obtained on a baseline commercial iron powder. Both sets of data were systematically collected using various powder/die lubrication combinations.