Study on damping behavior of A356 alloy after grain refinement

Damping capacity of A356 alloy refined by AlTiB master alloy was investigated over a temperature range of 30–300 °C using a dynamic mechanical thermal analyzer. Samples of dimensions 50 × 5 × 1 mm for damping measurement were obtained by spark machining. Experimental results show that refined A356 alloy exhibits much higher damping capacity than that of A356 base alloy. With testing condition of room temperature and frequency of 1 Hz, the damping capacity is 12.3 × 10−3 for refined A356 alloy, increased by 8 × 10−3 compared to A356 base alloy. The improvement in damping capacity of refined A356 alloy is ascribed to the change of Si size and grain refinement.