Application of shortened heat treatment cycles on A356 automotive brake calipers with respective globular and dendritic microstructures
(1. Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa;
2. Department of Materials Science and Metallurgical Engineering, University of Pretoria, South Africa)
2. Department of Materials Science and Metallurgical Engineering, University of Pretoria, South Africa)
Abstract: Since the automotive industry has many possible applications for semi-solid metal (SSM)−high-pressure die casting (HPDC) parts, the newly developed heat treatment cycles, as well as the traditional heat treatment cycles, were applied to A356 brake calipers cast using a LK DCC630 HPDC machine. Vickers hardness measurements at a cross section of the brake calipers were performed, indicating that similar values can be obtained when using the significantly shorter heat treatment cycles. Finally, the typical tensile properties that can be obtained for SSM-HPDC A356 brake calipers are compared with those manufactured by gravity die casting. Results indicate that the differences in microstructures (globular or dendritic) do not have a noteworthy effect on the heat treatment response. This implies that the short heat treatment cycles originally developed for globular SSM-HPDC A356 castings can be successfully applied to dendritic liquid A356 castings too.
Key words: semi-solid metal (SSM) forming; heat treatment; A356; brake caliper; gravity die casting; automotive