铸造2017，Vol.66Issue(12)：1262-1268,1272,8.
多元稀土对半固态A356铝合金梯度细化的研究
Research on Gradient Refinement of Semisolid A356 Alloy by Multiple-Element Rare Earth
摘要
Abstract
Based on the mechanism of refining solidification structure resulted from eutectic reaction induced by rare earth in aluminum alloy, the Gd-Nd-Y-Ce quaternary rare earth composite refiner was designed, supplemented by gradient thermal insulation measures. Through making the semisolid A356 aluminum alloy in heat preservation phase in accordance with the Al-RE eutectic temperature from high to low successive eutectic reaction, to improve the survival of eutectic products was ensured. The effect of complex rare earth on semisolid A356 aluminum alloy solidification gradient refining was researched. The results show that the addition contents of quaternary rare earth were determined according to the orthogonal experiment design. Under the conditions of 650 ℃pouring temperature, and gradient thermal insulation according to the 645 ℃/30 s-635 ℃/40 s-625 ℃/50 s-615 ℃/60 s, and 615℃water quenching demould, the refining characteristic parameters of different samples were obtained through the formula. By comprehensive balance method, analysis of the extreme-difference R and test-index Ki of the orthogonal experiment parameters, the optimal proportion of the quaternary rare earth was found as follows: 0.5％Gd+0.2％Nd+0.4％Y+0.2％Ce. The primary phase A356 aluminum alloy of average equal-area diameter is 83.013μm, and the shape factor is 0.817, the refining effect is best.关键词
半固态/A356铝合金/四元稀土/梯度保温/细化机制Key words
semisolid/A356 aluminum alloy/quaternary rare earth/gradient isothermal holding/refinement mechanism分类
矿业与冶金引用本文复制引用
孙梦桐,刘政,陈志平,陈涛..多元稀土对半固态A356铝合金梯度细化的研究[J].铸造,2017,66(12):1262-1268,1272,8.基金项目
国家自然科学基金项目(51361012) （51361012）
江西省自然科学基金项目(20114bab206014) （20114bab206014）
科技落地计划(KJLD12070)资助. （KJLD12070）
