摘要
采用氩气雾化方法制备了Al82Ni10Y8合金粉末,利用扫描电镜、透射电镜、X射线衍射仪和差示扫描量热仪(DSC)对粉末的微观结构、相组成及热稳定性进行了分析。研究结果表明,粒径小于20μm的Al82Ni10Y8雾化粉末结构为典型的非晶态,粒径大于20μm的粉末由非晶基体+晶化相组成;优先出现的晶化相为含少量Ni和Y的fcc Al,大直径的粉末出现树枝状结构;粒径小于26μm的Al82Ni10Y8雾化粉末具有明显的玻璃化转变和晶化现象,和ΔTx分别为539K,561K和22K。当连续升温时,Al82Ni10Y8雾化粉末的DSC曲线出现3～4个放热峰,Tg,Tx1表现出多级晶化现象。
The morphology, microstructure, thermal stability, phase composition and microhardness of the argon atomized Al_(82)Ni_(10)Y_8 powders were investigated by scanning electron microscope, differential scanning calorimetry (DSC), X-ray diffractometry and transmission electron microscope. Most of the powders are spherical in shape, but the surface morphology is different for the powders with different size. The surface of powders below 26 μm in diameter is (very) smooth, while those larger than 26 μm presents rough surface induced because of non-(equilibrium) (solidification.) The cross-section microstructure of Al_(82)Ni_(10)Y_8 atomized powder below 20 μm in diameter is amorphous. The structure of the powder above 20 μm consists of amorphous matrix and crystallization phase. The fcc-Al phase contains Ni and Y elements. For the powder below 26 μm in diameter, its glass transition temperature, crystallization temperature, and temperature interval of the supercooled liquid region is about 539 K, 561 K and 22 K, respectively. The DSC curves of the atomized powder has three or four distinct exothermic peaks, which indicates that the crystallization process of Al_(82)Ni_(10)Y_8 powder is multi-stepped.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第5期707-713,共7页
Journal of Central South University:Science and Technology
基金
国家"863"高技术计划项目(2003AA302520)
关键词
铝基合金
非晶态结构
气体雾化
粉末冶金
Al-based alloy
amorphous structure
gas atomization
powder metallurgy
