Synthesis of in situ Al–TiB2 composites using stir cast route
Synthesis of in situ Al–TiB2 composites using stir cast route
复制标题
DOI：
10.1016/s0263-8223(00)00030-1
复制
发表时间：
1999-12
影响因子：
6.3
通讯作者：
K. L. Tee;Ling Lu;M. Lai
中科院分区：
文献类型：
--
作者：
K. L. Tee;Ling Lu;M. Lai
在1000℃以上的Al熔体中加入元素Ti和B粉，通过Al-Ti-B放热反应生成细小的原位TiB2颗粒。通过对TiB_2形核的优化，合成的Al-15Vf%TiB_s复合材料的抗拉强度和屈服强度是母材的两倍。在峰值时效条件下，添加4.5wt%的铜可以使铝基合金的抗拉强度和屈服强度提高两倍。在Al-Ti-B系复合材料中，由于脆性Al3Ti片层与TiB2颗粒的共存，使Al-Al和Al-Cu基复合材料的延伸率分别降低到68%和84%。当(Ti+B)混合物中加入3wt%C时，Al-Cu基复合材料中同时生成TiB2和TiC增强相。这种方法大大减少了复合材料中的Al3Ti化合物。虽然铜的存在促进了Al_3Ti的形成，但其对流动性的影响使熔体回复率从33%提高到52%。
When elemental Ti and B powders were added to molten Al at above 1000°C, fine in situ TiB2particulates were formed through Al–Ti–B exothermic reaction. By optimising the nucleation of TiB2, the tensile and yield strengths of a synthesised Al–15Vf%TiBscomposite were twice that of matrix material. Modification of Al-matrix with 4.5 wt%Cu tripled the tensile and yield strengths at peak-aged condition. Owing to the co-presence of brittle Al3Ti flakes with TiB2particles in the composites synthesised by the Al–Ti–B system, ductility was reduced to 68% and 84% in composites with Al- and Al–Cu matrices, respectively. When the (Ti+B) mixture was incorporated with 3 wt%C, TiB2and TiC reinforcing phases were simultaneously produced in the composite with Al–Cu matrix. Such an approach reduced Al3Ti compound in the composite considerably. Although the presence of Cu in the composite was found to promote the formation of Al3Ti, its effect on the fluidity caused the melt recovery to increase from 33% to 52%.