稀土元素La对Ni_(75)B_(17)Si_8非晶合金形成能力和热稳定性的影响

EFFECTS OF RARE-EARTH ELEMENT La ON GLASS FORM-ING ABILITY AND T HERMOST ABILITY OF Ni-B-Si METALLIC GLASS

本文发现微量稀土元素在某些合金中可不呈均匀固溶态分布,而与母合金某些原子反应生成高熔点化合物,或吸附于合金中异质核心表面改变其异质形核的活性。当稀土元素以这种状态存在时,不但失去稳定非晶相的作用,而且促进异质形核,降低合金的非晶形成能力和热稳定性。

Small amount of rare-earth elements may have negative effects on the formation of some metallic glass alloys. The rare-earth elements may react with some atoms of the alloys to form compounds of high melting points or be absorbed on the surfaces of the heterogeneous catalysts in the alloys to activate the heterogeneous nucleation. In this case, the rare-earth elements have no effects on enhancing the stability of the metallic glass phase but enhance the heterogeneous nucleation and decrease the metallic glass forming ability and thermostability.