加钛方式对A356合金晶粒细化效果和衰退行为的影响

分别采用电解加钛、熔配加钛和氟盐加钛三种方式，研究了加钛方式和保温时间对A356合金的晶粒细化效果和抗衰退能力的影响。结果表明，在钛含量（0．1％）相同条件下，短时保温时，电解加钛的晶粒细化能力高于熔配加钛和氟盐加钛，电解加钛A356合金的一次枝晶臂间距最短；长时间保温后，各种加钛方式使A356合金晶粒和共晶硅均发生了不同程度的衰退，但电解加钛A356合金的抗衰退能力最强，氟盐加钛合金的抗衰退能力最低。

Influence of Titanium Alloying Methods on Grain Refinement Effect and Fading Behavior of A356 Alloys

The influence of titanium alloying methods and holding time on the grain refinement effect and its fading was investigated and compared by adding titanium by electrolysis,melting Al-10Ti master alloys and adding K2TiF6 respectively.The results show that the ability of grain refinement of A356 alloys alloyed by electrolysis is obviously higher than that of others when the alloys with the same titanium content(0.1%) during the short holding time.The primary dendrite length of A356 alloy by electrolysis is the most short.The fading of grain refinement effect takes place for all alloys when prolonging the holding time.The Si particles are obviously coarsened.But the A356 alloys alloyed by electrolysis have the most optimum fading resistance of grain refinement,while for the alloys alloyed by melting K2TiF6,the fading resistance of grain refinement is the lowest compared with others.