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

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.%, 57.7 wt.% and 66.8 wt.% for 6TiB2/Al-5Cu with 0.2 wt.%, 0.5 wt.% and 1 wt.% Y, accordingly.

Graphical AbstractFracture surfaces of 6TiB2/Al-5Cu (a), 0.2Y-6TiB2/Al-5Cu (b), 0.5Y-6TiB2/Al-5Cu (c) and 1Y-6TiB2/Al-5Cu (d); force curves of 6TiB2/Al-5Cu (e), 0.2Y-6TiB2/Al-5Cu (f), 0.5Y-6TiB2/Al-5Cu (g) and 1Y-6TiB2/Al-5Cu (h)Figure optionsDownload full-size imageDownload as PowerPoint slide