母合金铸锭组织对Zr_(60)Al_(15)Ni_(25)合金玻璃形成能力的影响  

Influence of Ingot Microstructure on Glass Forming Ability of Zr_(60)Al_(15)Ni_(25) Alloys

作　　者：闫志杰[1] 李金富[1] 何顺荣[1] 周尧和[1] 王鸿华[1] 

机构地区：[1]上海交通大学金属基复合材料国家重点实验室

出　　处：《上海交通大学学报》2003年第10期1509-1512,共4页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(50071032)

摘　　要：通过改变反复重熔次数获得了具有不同凝固组织的母合金铸锭.结果发现,母合金铸锭的凝固组织随着熔炼次数的增加而明显细化.通过差示扫描量热法(DSC)研究了母合金铸锭凝固组织对大块非晶形成合金Zr60Al15Ni25玻璃形成能力的影响.实验结果表明,随着母合金铸锭凝固组织的细化,非晶合金的玻璃转变温度Tg提高;约化玻璃转变温度Trg增大;合金的熔化焓ΔHf减小,凝固过程中的结晶驱动力降低,抑制了形核,有利于非晶的形成.由于结构的遗传性,细化的铸锭重熔至同一吸铸温度时,相应的合金熔体的短程序尺寸变小,在随后的快冷过程中保留到非晶基体中的短程序尺寸减小,非晶晶化时原子的重组变得困难,因而Tg提高.The mother ingots with different microstructures were obtained by varying the number of repeated melting times. It was found that the ingot microstructure becomes finer and finer as the repeated melting times increase. The influence of the ingot microstructure on the glass forming ability of Zr60Al15Ni25 alloy was investigated by differential scanning calorimetry (DSC). The results indicate that, as the ingot microstructure becomes finer, the corresponding glassy alloy shows a higher glass transition temperature Tg and reduced glass transition temperature Trg. Besides, the fusion enthalpy ΔHf of the alloy with a finer microstructure reduces, suppressing the nucleation of the primary phase during the solidification process of the liquid alloy, which makes the formation of glassy phase easier. The finer ingot microstructure leads to the smaller size of short-range orders in the corresponding liquid at the same casting temperature. After the subsequent solidification, the short-range orders frozen in the glassy alloy become smaller, which makes the rearrangement of atoms more difficult during the crystallization of the glassy alloy. As a result, the glass transition temperature Tg increases.

关 键 词：铸锭组织 大块非晶合金 玻璃形成能力 短程序 

分 类 号：TG139.8[一般工业技术—材料科学与工程]