Study of the Mechanical Properties for an Automotive Part under Squeeze Casting Process

Abstract

Squeeze casting is process capable to produce high integrity parts. To minimize gas porosity, melt front’s speed must be kept as minimum as possible to ensure the laminar flow pattern with adequate flow rate to be able to fill the cavity before liquid metal is solidified. In this study, the indirect squeeze casting process was adopted to cast a motorcycle’s component originally produced by a high pressure die casting (HPDC) process. Based on shape and dimension of the parts to get the real castings for the mass production, melt’s speed must be higher than the level reported by the literatures (around 1 m/sec). As a result, a fully laminar flow may not be achievable. This is confirmed by the primary study of the process parameters and tooling design using the casting process simulation. Castings from two processes were casted and then mechanically and micro-structurally compared for both as cast and heat treated conditions. Results from the experiment have shown that size of gas porosity found in squeeze casts reduced significantly, while gain size of the squeeze casts trended to be bigger than that of HPDC casts. In terms of the mechanical properties, the ultimate tensile strength of as cast from both processes was not significantly different, while the heat treated squeeze casts has shown the big improvement compared with the as casts.