M. Maniruzzaman, R. D. Sisson, Y. Rong, Worcester Polytechnic Institute, Worcester, MA; D. Caswell, Alfe Heat Treating, Defiance, OH; P. N. Crepeau, GM Powertrain, Pontiac, MI

Summary: A356 aluminum alloy engine cylinder heads were produced using lost foam casting process. To dissolve the nonequilibrium second phase, the heads were solution heat treated by holding at 1000oF in a batch furnace and then rapidly quenched in an agitated water tank. The cylinder head was instrumented using several thermocouples at some strategic locations to measure the time-temperature response during heating, holding and quenching. Effects of racking and solutionizing time were investigated and the results are presented in the paper. Based on the experimental findings, an optimum solution heat treatment process for aluminum alloy engine head is proposed.