2009 Volume 49 Issue 11 Pages 1700-1709
A new rheocasting process was applied to develop a diesel engine block using ADC10 alloy. This type of diesel engine block requires much higher mechanical properties for a high engine power, and this is why heat treatment for improving mechanical properties should accompany processing. Therefore, the manufacturing process for a diesel engine block must prevent inner defects such as blow-holes, gas porosities and shrinkages. Rheocasting is considered as a manufacturing technique for this purpose. In order to apply the rheocasting technique in manufacturing a diesel engine block, it is important to produce large-volume slurry. Establishing the injection condition has been particularly focused on for the integral inner parts. The Advanced Rheocasting Technology (ART) system, in this study, was used for large-volume slurry with ADC10 alloy. Through computer simulation, the injection condition was determined to stabilize feeding patterns which were verified from experimental results. Various heat treatments were tested to determine the optimal condition for the rheocast diesel engine block. The rheocast engine block showed fine and uniform microstructures, where the average diameter of primary α-globules was 75 μm and its form-factor indicating the degree of globularity was 0.83 including gas contents below 4cc/100 g Al. Mechanical properties indicated 317 MPa Ultimate Tensile Strength (UTS) and 1.2% elongation good enough for the objective usage after modified T6 heat treatment.
