Improvement of yttrium on the hot tearing susceptibility of 6TiB₂/Al-5Cu composite

张晓波，孙靖，汪明亮，张亦杰，马乃恒，王浩伟

State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University

摘 要：To improve the severe hot tearing susceptibility of TiB₂ reinforced Al-5Cu matrix composites,the present research investigated the influence of Y on the hot tearing susceptibility of 6TiB₂/Al-5Cu composite.For the composite added with Y,the solidification temperature range was shortened,which was caused by the novel τ₁-Al₈Cu₄Y phase.The grain size of 6TiB₂/Al-5Cu composite was 39.8 μm.The addition of Y promoted the grain refinement,and the grain sizes were 36.33,33.42 and 26.77 μm for 6TiB₂/Al-5Cu with 0.2 wt.%,0.5 wt.%and 1 wt.%Y,respectively.The decrease of solidification temperature range and grain size was beneficial to the hot tearing susceptibility improvement.Furthermore,the hot tearing initiation force increased from 44 to 288 N,when 1 wt.%Y was added in 6TiB₂/Al-5Cu.For the above significant influence,the hot tearing susceptibility values were reduced by 12.2 wt.%,57.7wt.%and 66.8 wt.%for 6TiB₂/Al-5Cu with 0.2 wt.%,0.5 wt.%and 1 wt.%Y,accordingly.

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