摘要:
A novel technique for fabricating TiB
2/Al composites in molten aluminum was introduced. The formation mechanism of brittle Al
3Ti particulates up to 30 m in size produced in the composites was studied and a method of eliminating them was proposed. The results show that (1) the brittle Al
3Ti particulates are always present in the composites when the molar ratio of Ti to B
nTi:
nB is 1:2; and (2) the formation of the brittle Al
3Ti phase can be avoided entirely from the final product by using a proper
nTi:
nB of l:4 in the Ti-B-Al preforms.In the former case, the tensile elongation of the composite is only 4%, much lower than the value of pure aluminum (20%). In the later case, the tensile elongation of this composite is 10%, higher than the value of the composite with a lot of Al
3Ti (4%), whereas the ultimate tensile strength of the former is nearly that of the later.