Microstructure and nanohardness of Ti-48%Al alloy prepared by rapid solidification under different cooling rates

The influence of cooling rate on the microstructure and nanohardness of the rapidly solidified Ti-48%Al alloys prepared by melt spinning method was studied. The results show that the microstructure of the rapidly solidified ribbons is refined and homogenized compared with that of the conventionally cast mother alloy. With increasing the cooling rate, the grain size decreases greatly. The relationship between the ribbon thickness and the wheel speed was examined, and the effect of the wheel speed on the cooling rate was also studied. It was found that the ribbon thickness decreases inversely with the wheel speed. The nanohardness increases with increasing cooling rate due to the grain size strength.