块体非晶合金的黏度与玻璃形成能力的关系  

Correlations between viscosity and glass-forming ability in bulk amorphous alloys

作　　者：危洪清[1,2] 龙志林[1] 张志纯[1] 李乡安[1] 彭建[1] 张平[1] 

机构地区：[1]湘潭大学土木工程与力学学院,湘潭411105 [2]邵阳学院机械与能源工程系,邵阳422000

出　　处：《物理学报》2009年第4期2556-2564,共9页Acta Physica Sinica

基　　金：湖南省科技厅科技计划(批准号:2008FJ3095)资助的课题~~

摘　　要：基于经典结晶理论讨论了非晶合金的晶化动力学因素和晶化热力学因素对玻璃形成能力(GFA)的影响.分析表明,合金的等温转变(TTT)曲线"鼻尖"温度Tn对应的黏度与晶化阻力因子成正比;重新加热时晶化开始温度Tx对应的黏度与晶化驱动力因子成反比.由此得到了新的GFA参数ω0=(Tg-T0)/(Tx-T0)-(Tg-T0)/(Tn-T0),其中Tg为玻璃转变温度,T0为理想玻璃转变温度.统计结果显示,ω0与临界冷却速率具有较高的相关性,R2高达0.9626.进一步分析表明:新提出的ω0参数可以合理地解释过冷熔体的黏度、脆性、液相稳定性、热稳定性以及Trg、ΔTx、γ、γm、ΔTrg、α、β、δ和φ等参数与GFA的关系.According to the classical crystallization theory,the influences of kinetics and thermodynamics on glass-forming ability（GFA）for bulk metallic glasses has been investigated.The theoretical analysis shows that crystallization resistance is in proportion to the viscosity of ＂nose＂ temperature（Tn）while crystallization driving force is inversely proportional to the viscosity of crystallization onset temperature（Tx）on reheating in time-temperature-transformation（TTT）curve,and therefore a GFA parameter ω0,defined as（Tg-T0）/（Tx-T0）-（Tg-T0）/（Tn-T0）,was proposed（wherein Tg and T0 are glass transition temperature and Vogel temperature respectively）.The parameter ω0 shows an excellent correlation with the critical cooling rate for glass formation of bulk metallic glasses,with the statistical correlation factor of R2=0.9626.Furthermore,the relationships between the GFA and Trg,ΔTx,γ,γm,ΔTrg,α,β,δ and φ,as well as the fragility of liquid could be explained reasonably based on our proposed ω0 parameter.

关 键 词：块体非晶合金 黏度 脆性 玻璃形成能力 

分 类 号：TG139.8[一般工业技术—材料科学与工程] TS802.3[金属学及工艺—合金]