机械研磨形成W颗粒/La_(55)Al_(25)Cu_(10)Ni_5Co_5金属玻璃基复合材料  

FORMATION OF W PARTICLES/La_(55)Al_(25)Cu_(10)Ni_5Co_5 GLASSY ALLOY MATRIX COMPOSITES BY MECHANICAL MILLING

作　　者：张晓强[1] 徐坚[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家峨合)实验室,沈阳110016

出　　处：《金属学报》2004年第6期647-652,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金 59971054和50021101

摘　　要：利用X射线衍射、透射电子显微镜和差示扫描量热计分析表征了La_(55)Al_(25)Cu_(10)Ni_5Co_5合金及其添加W颗粒后高能球磨产物的结构与相转变.由数个金属间化合物构成的La_(55)Al_(25)Cu_(10)Ni_5Co_5合金经过机械研磨可转变为与熔体过冷形成的金属玻璃相类似的玻璃态合金,过冷液态温度区间的宽度ΔT_x可达到76K.合金与W颗粒(体积分数10％-30％)的混和物机械研磨后,形成W纳米颗粒弥散分布于La基玻璃态合金基体上的复合材料.随着W含量的增加,基体合金的玻璃转变温度T_g和晶化起始温度T_(xl)均提高,同时ΔT_x增大,含30％W的复合材料,基体玻璃态合金的ΔT_x可达到92K.Prealloyed powders of La_(55)Al(25)Cu(10)Ni_5Co_5 and its mixtures with tungsten particles were subjected to a high--energy ball milling. Structural evolution in the milled products was charac- terized using X--ray diffraction, transmission electron microscopy and differential scanning calorimetry. Mechanical milling of La_(55)Al(25)Cu(10)Ni_5Co_5 alloy consisting of several intermetallics results in a forma- tion of glassy alloy similar to that obtained by melt undercooling. The La--based glassy alloy formed by ball milling exhibits a well--defined glass transition and wide supercooled liquid region, △T_X, about 76 K. For the ball--milled mixtures of the intermetallics with tungsten particles up to 30% (volume fraction), the composites formed, in which tungsten particles were refined to a size around 5--120 nm and dispersed in glassy alloy matrix. With increasing the tungsten content, the glass transition tem- perature, T_g, and onset temperature of crystallization, T_(X1), of the matrix alloy shifted towards a higher temperature, accompanied by an extension of △T_X. The △T_X value about 92 K is achieved in the composite with content of 30% W.

关 键 词：机械合金化 非晶态合金 玻璃转变 La合金 

分 类 号：TB383[一般工业技术—材料科学与工程]