Effect of injection velocity on porosity formation in rheocast Al component using RheoMetal process

• Published in: International journal of cast metals research (Online) 2010-06, Vol.23 (3), p.158-163
• Main Authors: Cao, H., Wessén, M., Granath, O.
• Format: Article
• Language: English
• Subjects: INJECTION VELOCITY; MICROSTRUCTURE; POROSITY; RHEOCASTING; SEMISOLID; SSM
• ISSN: 1364-0461; 1743-1336; 1743-1336
• DOI: 10.1179/136404609X12565676328682

Rheocasting is on its way to establish as a cost efficient method for producing high integrity aluminium components. There is still, however, a need to learn more about the possibilities and limitations of this relatively new process in industrial use. This especially relates to ingate design and machine process parameters, e.g. shot profile, die temperature and intensification pressure, for obtaining sound quality. A component was produced by rheocasting at varying phase II velocities in a normal high pressure die casting machine supplied with a RheoMetal station. The component quality was investigated in the most massive section of the casting, using X-ray and metallographic techniques. The pore content and its distribution were found to strongly depend on the injection velocity where a low velocity is preferred due to the low risk for air entrapment and the higher fraction solid obtained at completed die filling, thereby reducing the solidification shrinkage.