离心力对TC4钛合金铸件孔洞及线收缩率的影响

Effects of Centrifugal Forces on Porosity and Dimensional Contraction Rate of TC4 Alloy Castings

采用真空石墨型立式离心铸造方法,研究了离心力大小对Ti-6Al-4V(TC4)钛合金铸件内部孔洞率以及铸件宏观尺寸收缩率的影响。结果表明,随着重力系数的增加,铸件中的孔洞率呈指数方式明显减小,给出了两者之间统计关系的表达式;离心转速从0增加到210r/min时,阶梯铸件长度方向尺寸收缩率呈较明显的减小趋势;同一浇注工艺条件下,与离心力相比,铸型的冷却能力对铸件线收缩率的影响更显著。

Effects of centrifugal forces on porosity rate and dimensional contraction rate of Ti-6Al-4V(TC4) alloy casting,which was prepared with vacuum graphite mould by vertical centrifugal casting,were investigated. The results reveal that with the increase of gravity coefficient,the porosity rate in the casting is decreased as a function of exponent,and the corresponding regression equation is presented. With increasing in rotating velocity from 0 to 210 r/min,dimensional contraction rate of the multi-step castings in length is significantly decreased. At a given pouring condition,the effects of casting mould on dimensional contraction rate are higher that those of centrifugal forces.