Spray forming of magnesium alloys and composites

Rapid solidification can play an important role in the development of high performance magnesium alloys and composites. The investigation reported concentrated on spray forming of magnesium alloys which are difficult to cast, i.e. those with a high content of intermetallic phases, e.g. with rare earths, aluminium, or calcium. The process parameters were found to exert a considerable influence on the microstructure and properties of particle reinforced magnesium matrix composites. The examined composites consisted of commercial QE22 alloy with small silicon carbide particles (8-12 mu m) as reinforcement. After spray forming the alloys were extruded followed by characterisation of the resulting microstructure and determination of mechanical properties. The results are discussed for the various systems investigated and compared with those for extruded PM material. (C) 1997 Osprey Metals Ltd.