Sintering Fundamentals of Magnesium Powders

Magesium and its alloys are attractive materials for use in automotive and aerospace applications because of the low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. This work reviews the efforts to improve the attractiveness of magnesium through non-traditional processing and presents results of current efforts to produce magnesium alloys via powder metallurgy (P/M). P/M can be used to alleviate the formability problem through near-net-shape processing and also allows unique chemical compositions that can lead to new alloys with novel properties.The feasibility of producing magnesium powder metallurgy products utilizing the industrially dominant process of mixed powder blending and controlled atmosphere sintering was investigated using uniaxial die compaction and cold isostatic pressing to form the compacts. Two types of pure magnesium powder were used: one produced by mechanical grinding and the other by centrifugal atomization. The optimal processing conditions (powder size, compaction pressure, sintering time and temperature) were found to maximize sintered density and mechanical properties.