Kiyoshi Shibata

Effect of High Thermal Conductivity Die Steel in Aluminum Casting

Recently, the application of aluminum die cast parts in automobile manufacturing has increased because of the greater demand for automotive weight reduction. For even wider application, it is necessary to reduce manufacturing costs and improve product quality. A material possessing a thermal conductivity 50% higher than the conventional 5% chromium hot work tool steel, AISI-H13, was developed as a die material for high- and low-pressure die casting machines.In this research, the product cooling rate for dies using this type of steel was faster than with the conventional steel, and it was hypothesized that cycle time may be shortened and product cost reduced. A ferrous material with high thermal conductivity, HDS-1, was developed for application to die casting dies. Thus, HDS-1 was used to produce a water jacket core of an engine block die for a high-pressure die casting machine and the cylinder head upper die of a low-pressure die casting machine. The result was a reduced die surface temperature, with the faster cooling rate verified through analysis of the microstructures of the die-cast parts. The results of test application of these dies using the high thermal conductivity material suggest that it is possible to improve tool service life and casting quality simultaneously.