High Quality Magnesium Castings by the New Rheocasting (NRC) Approach

摘要

Metallurgical and processing aspects of New Rheocasting (NRC) are discussed in terms of microstructural analysis of the slurry and the NRC castings, and in terms of mechanical properties. The basic concept of NRC is explained and possible production equipment is introduced. The process is based on controlled cooling of a slightly superheated melt. This controlled cooling is performed in a carousel slurry maker. The semi-solid slugs are then cast to shape in a Vertical Squeeze Casting machine. Special focus is put on the requirements on Mg - alloys for semisolid forming, and it will be shown that proper alloy design can stabilize the process and improve reproducibility of the casting properties. Magnesium casting and wrought alloys will be checked for semi-solid castability, and trial results will be presented. The results are compared with characteristic properties of High Pressure Die Cast magnesium. An innovative recycling concept for low - cost reuse of globular semi-solid runners and scrap will be presented.