La55Al25Ni20大块非晶合金对ZA27合金凝固组织的影响

将La55Al25Ni20大块非晶合金加入到ZA27合金中,研究了非晶合金对ZA27凝固组织的影响。发现加入非晶合金后的ZA27铸锭组织中析出枝晶状、块状、小花状等第二相。第二相随机分布在基体中,使基体枝晶细化。添加等量的La55Al25Ni20晶体合金时未析出小花状第二相,且对一次枝晶的细化效果不如添加非晶合金好。电子探针（EPMA）试验结果表明,析出的第二相中含有较多的Zn元素,使初生α＇相枝晶发育不完全,产生细化,且造成了麻点区的扩大。合理利用非晶独特的晶化过程,为La55Al25Ni20大块非晶在合金添加剂方面的应用开拓了新的途径。

Effects of La55Al25Ni20 Bulk Metallic Glass Addition on Microstructure of ZA27 Alloy

The effects of addition of La55Al25Ni20 bulk metallic glass into ZA27 alloy are investigated. The results show that withaddition of La55 Al25 Ni20 metal glass alloy various kinds of precipitated phases, such as dendritic, flower and small block phases are found; while with equal addition of the crystalline alloy, there is no flower-like phase in the structure. The metallic glass addition greatly decreases grain size by reducing the dendrite crystals of primary or phase; however the addition of the crystalline alloy shows little refinement for the primary dendrite. EPMA results illustrate that the precipitated phases have rich Zn element which results in underdevelopment of primary or phase, refinement and expanding of mottled area. Proper use of crystallization characteristics of the metallic glass can expand application of the metallic glass in alloy additives.