钇对过共晶铝铁合金组织形貌的影响

针对普通熔铸条件下过共晶Al-Fe合金中初生富铁相严重割裂基体、恶化合金性能的问题,采用稀土元素Y对Al-5?合金进行变质处理。实验结果表明:稀土元素Y抑制了初生富铁相在原有形核基底上生长的趋势,促进初生相形核,对其形态、大小和分布均有显著影响;加入0.1%的Y时,初生富铁相由粗大针片状变为较均匀的花朵状;当Y的加入量增加到0.5%时,初生富铁相向细小的团球状转变,分布均匀;继续增加Y的加入量时,开始出现针片状及少量大花朵状的初生富铁相,组织不均匀,且逐渐粗化。

Influence of Yttrium on the Microstructure of Hypereutectic Al-Fe Alloys

In order to solve the problems of the primary Fe-rich phase separating the metal matrix seriously and deteriorating the property of hypereutectic Al-Fe alloy, rare earth (Y) metal was used to modify Al-5? alloy. Results showed that when Y is added the growth tendency of the primary Fe-rich phase is depressed, the nuclei of the primary phase are increased and the morphology, size, and distribution of the primary phase are influenced significantly. When 0.1% of Y is added, the shape of primary Fe-rich phase is changed from coarse, needle-like shape to more uniformly distributed flower-like shape; and when addition of Y is increased to 0.5%, the morphology of primary Fe-rich phase is turned to well-distributed fine, round shape. When addition of Y is increased further, needle-like and a little flower-like Fe-rich phase appears, and the microstructure becomes coarse and non-uniform.