Z. Bian
,
G. He and G.L. Chen (State Key Laboratory for Advanced Metals and Materials
,
University of Science and Technology Beijing
,
Beijing 100083
,
China) J. Lu
,
D.J. Chen
,
G.C. Tu
,
G.J. Chen and X.J. Hu (Shougang Metallurgical Research Institute
,
Beijing 100085
,
China)
金属学报(英文版)
Al80Ni6 Y8 Co4 Cu2 amorphous ribbons were isothermally annealed and a mixed structure consisting of α-Al particle with a size of less than 15nm and Al3Ni compound with a size of about 30nm was obtained. The crystallization kinetics of Al80Ni6 Y8 Co4 Cu2 amorphous alloy shows that the precipitation of α-Al particles is the growth process controlled by diffusion of the solute elements rejected from the growing crystals. By quenching at different cooling rates, a mixed structure consisting of nanoscale α-Al particles and the remaining glass matrix or structure consisting of nanoscale particle (Al phase or Al3Ni compound) with a size of about 100nm was formed. The addition of Co elements and Cu elements to Al-Ni-Y alloy systems increases the glass formation ability of the alloy and the thermal stability of the supercooled liquid region against crystallization, which results from significant difference of atomic size, strong bonding nature among constituent elements and the low diffisivity of the solute elements due to the concentration gradient in the growing front of crystals.
关键词:
a mixed structure
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张淑婷
,
郭东海
,
王辉
,
万伟伟
,
马尧
稀有金属材料与工程
采用真空雾化的方法制备了不同氧含量的CoNiCrAlY合金粉末.采用质量增量变化、增重相对速率、XRD、SEM和能谱分析研究不同氧含量的CoNiCrAlY合金粉末1000℃的氧化行为,并进行了超音速火焰喷涂,对涂层的微观结构进行对比分析.结果表明,粉末氧化质量增量随时间变化明显,前期呈线性关系,后期则呈抛物线关系.XRD析测到Al2O3氧化物,其衍射峰随时间增长而增强,粉末的抗氧化性能与氧含量的浓度梯度有关.
关键词:
CoNiCrAlY粉末
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质量增量
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氧化速率
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涂层
