Effect of Different Oxide on In-situ Synthesis of Al₂O₃ Whiskers in Ti-Al System

Al2O3 whiskers in Ti-Al matrix were successfully synthesized by in situ reaction using Ti powders and Al powders as raw materials doped with two kinds of oxide additives.The effects of different oxides on the in-situ synthesis of Al2O3 whiskers was studied by using XRD and SEM.The results indicate that the whiskers were short and rough when Nb2O5 was added,a large number of whiskers appeared after syntheiszed at 1 100 ℃.When TiO2 was used as additive,after synthesized at 890 ℃,more and more longer and straighter whiskers having good slenderness ratio were formed.If the temperature was higher (1 040 ℃),irregular columnar fibres with rough surface were formed.