Correlation between Melt Quality and Fluidity of A356

Aluminium and its alloys are prefer choice of automotive parts due to their low density and high strength ratios. These critical applications requires high quality castings to be produced. Melt quality can be measured by bifilm index using reduced pressure test. This index is a numerical indication of bifilm quantity of the melt. It has been shown that these bifilms affect many of the properties significantly. One of the limiting factor of casting methods is the fluidity of the liquid metal. The aim of the study is to investigate the effect of bifilms (i.e. melt quality) over the fluidity of A356 by using spiral test mould. Different mould temperatures were studied and it was found that as the bifilm index was increased, the scatter of the test results was increased.