加压退火对(La_(0.6)Ce_(0.4))_(65)Al_(10)Cu_(25)块体非晶合金晶化行为和热稳定性的影响  

Effects of Preannealing under Pressure on the Crystallization Behavior and Thermal Stability of(La_(0.6)Ce_(0.4))_(65)Al_(10)Cu_(25) Bulk Metallic Glasses

作　　者：刘彤[1] 朱亚蓉[1] 张涛[1] 

机构地区：[1]北京航空航天大学航空材料与服役教育部重点实验室,北京100191

出　　处：《稀有金属材料与工程》2012年第3期452-456,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金重点项目(50631010);国家自然科学基金面上项目(50771006);航空科学基金(2009ZF51062);高等学校博士学科点专项科研基金(20091102120009)

摘　　要：利用铜模铸造法制备了(La0.6Ce0.4)65Al10Cu25块体非晶合金,并在其过冷液相区内不同温度下,采用不同压力对该非晶合金进行加压退火处理,通过X射线衍射仪和差示扫描量热法研究了加压退火处理对该非晶合金晶化行为及热稳定性的影响。结果表明,加压退火促进了(La0.6Ce0.4)65Al10Cu25非晶合金的晶化过程,使得晶化初始温度Tx降低(dTx/dP=-5.17K/GPa),晶化激活能Ep随退火压力的增加而增大,并从能量和化学短程序畴的角度解释了加压退火对(La0.6Ce0.4)65Al10Cu25非晶合金晶化过程的影响机理。（La0.6Ce0.4）65Al10Cu25 bulk metallic glasses （BMGs） were prepared by copper-mold casting. The crystallization behavior and thermal stability of （La0.6Ceo.4）65Al10Cu25 were investigated by X-ray diffraction and differential scanning caloricity （DSC） after being annealed at its supercooled liquid region under the pressure ranging from ambient pressure to 1015 MPa. Results show that pressure promotes crystallization of （La0.6Ce0.4）65Al10Cu25 BMGs. The onset crystallization temperature Tx decreases with increasing of preannealing pressure at a slope of-5.17 K/GPa, and the apparent activation energy of the crystallization Ep determined by Kissinger equation increases with increasing of preannealing pressure. The influencing mechanism of preannealing under pressure on the crystallization of （La0.6Ce0.4）65Al10Cu25 BMGs were discussed in the view of Gibbs free energy and chemical short range order

关 键 词：非晶合金 加压退火:晶化行为 热稳定性 

分 类 号：TG139.8[一般工业技术—材料科学与工程]