La在含Cu的Al-Si合金中的作用研究

THE EFFECT OF LANTHANUM ON THE ALUMINIUMSILICON ALLOY CONTAINING COPPER

应用光学显微镜、电子探针等测试手段对La在含Cu的Al-Si合金中的作用进行了实验研究。结果发现:Cu对La的变质效果具有一定的抑制作用。这与La和Al,Si,Cu形成四元化合物有关。含Cu的Al-Si合金中能否加入La,取决于合金的使用状态。若合金使用在铸态条件下,并且其中含Cu量不高时,可以用La对合金进行变质;若合金使用在T_5(或T_6)状态下,则合金中不能加入La。

This paper deals with the effect of lanthanum on the aluminium-silicon alloy containing copper by use of optical microscopy and electron microp- robe.It is found that the copper is of some preventing action on the modi- fication of lanthanum in the alloy resulting from that the lanthanum can form four-component intermetallic compouud with Al,Si and Cu.Whether lanthanum can be added to the aluminium-silicon alloy containing copper depends on the used condition of the alloy.If the alloy is used in as-cast condition and the copper content is low lanthanum can be added to modify the alloy.If the alloy is used in T_5 or T_6 condition,lanthanum can not be added to the alloy for modification.