Slow-Shot High Pressure Die-Casting (SS-HPDC) Process for AE44 Magnesium Single-Cylinder Engine Block with Short-Fiber Reinforcement in the Bore

摘要

Single-cylinder magnesium engine blocks with short fiber reinforcement in the bore region were prepared by low speed (slow shot), high pressure die casting to infiltrate the fiber preforms and produce sound castings. The magnesium alloy was AE44 and the cylindrical preforms were made with silica-bonded Saffil fibers. The slow shot, high pressure die casting process (SS-HPDC) was intended to simulate squeeze casting, and processing parameters were identified and optimized. These included the pouring temperature, 760°C; the die temperature, 275°C; the preform preheat temperature, 750°C; and the intensification/infiltration pressure, 90MPa. Their relative contributions to the quality of the cast blocks is discussed and suggestions for further optimization are made. The slow-shot, high pressure die casting process is show to be an effective means for casting the blocks, which are free of porosity can be T4 or T6 heat-treated without metal blistering.