High velocity compaction of aluminum powder metallurgy alloys

Near-net-shape processes are alternative methods of manufacturing products which provide minimal raw material wastage and little need for secondary machining or finishing. Powder metallurgy (PM) technologies are some of the most popular near-net-shape processes, where powdered metals are pressed into complex product geometries. High velocity compaction (HVC) is an emerging PM technique which presses powders at velocities approaching 20 m/s. This technique can potentially produce near-uniform densities for relatively the same cost as conventional compaction techniques. The HVC research has accelerated from basic experimental trials to more in-depth investigations of its potential performance increases in the last decade. However, these activities have been centered primarily in European research centers. As an emerging technology, HVC may prove to be a vital competitive manufacturing technique and the proposed research program aims to have a significant impact on Canadian PM operations. The chief advantages of PM manufacturing are the significant cost savings due to reduced machining and material usage. Furthermore, when lightweight materials such as aluminum are considered, PM products offer a lightweight solution that is economically feasible. That is, lightweight products can be mass produced with marginal increases in manufacturing costs. The proposed work will focus on aluminum PM alloys as these hold a competitive advantage in the automotive sector, the PM industry's single largest client. The current challenge with aluminum PM processing is the non-uniform distribution of powder density of the pressed product, leading to poor strength and possible component failure. As such, the compaction process is critical to product performance and new compaction techniques are desired to improve density uniformity. In the proposed work an experimental HVC test method will be developed and supported by advanced numerical modeling of the process. One of the goals of this work is to develop accurate compaction models of aluminum PM products to better serve industrial practices by predicting optimum pressing parameters.