With respect to process and resource efficiency, semisolid casting processes, such as rheocasting, represent promising technologies for processing lightweight materials in the automotive industry. The reduced temperature of the melt during the casting process allows longer service life for the molds and less production rejects in industrial applications. However, up to now process–microstructure–property correlations have not been investigated in detail. Most studies focusing on these processes are producing simple geometries without a reduction in the cross section. Moreover, mechanical properties are only tested in the quasistatic regime. The present study investigates specimens taken from application-oriented parts. These specimens are examined comprehensively, i.e., from microstructure to the fatigue properties, and are compared to high pressure die cast counterparts. Based on the main findings, the following conclusion can be drawn: Although some differences can be found with respect to the microstructure appearance, under quasistatic loading the results are similar for the die cast and rheocast material (with a yield strength of 125 MPa and ultimate tensile strength of 240 MPa); however, with respect to fatigue properties in the low-cycle fatigue regime, the rheocast material shows reduced scatter: Thus, rheocasting is found to be the method of choice when improved fatigue properties are required.
Richter et al. (Mon,) studied this question.