摘要

A new Al-5Ti-0.75B-0.2C master alloy was successfully prepared by self-propagating high-temperature (SHS) reaction from an Al-Ti-B4C system with molten Al. Microstructure and phase characterization of the prepared Al-5Ti-0.75B-0.2C master alloy show that the nearly spherical TiC particles, hexagonal or rectangular TiB2 particles, and block like TiA1(3) particles distribute uniformly in the aluminum matrix. Grain refining test on commercial pure aluminum indicates that Al-5Ti-0.75B-0.2C master alloy exhibits a better grain refining performance than A1-5Ti-1B master alloy. By addition of 0.2 wt% Al-5Ti-0.75B-0.2C master alloy, the average grain size of of alpha-Al can be effectively refined to 160 5 gm from about 3000 gm, and the tensile strength and elongation are increased by about 20% and 14.1% due to the grain refinement.