赵九洲
,
李海丽
,
何杰
,
张显飞
金属学报
利用气体雾化方法研究了Cu--20%Co (质量分数) 合金的快速凝固行为, 获得了富Co相以微细球形粒子形式分布于基体的合金粉末. 建立了Cu--Co雾化液滴快速凝固过程模型,模拟分析了雾化液滴凝固的动力学细节. 结果表明:所建模型能很好地描述Cu--Co合金雾化液滴冷却凝固过程;液--液相变过程中组织演变是弥散相液滴形核、长大、碰撞凝并和空间迁移共同作用的结果; 雾化液滴尺寸越大,冷却越慢, 富Co相液滴的形核速率越低, 凝固后富Co相的弥散度越差.
关键词:
Cu-Co合金
,
Rapid solidification
,
Atomization
,
Modeling
O.P.P
,
ey
材料科学技术（英文）
Two commercial grade aluminum based immiscible bearing alloys were spray-deposited using convergent-divergent type of nozzle. The processing parameters for spray-deposition were adjusted in such a way that most of the droplets arrived on the deposition substrate in either liquid or semi-liquid state. The microstructural features of spray-formed and as-cast alloys are compared. In spray-formed alloys equiaxed grains were observed. The cell boundaries and intercellular regions were observed to be decorated with sub-micron sized particles whereas in normal casting the second phase was observed to be segregated along grain boundaries. The morphology and distribution of second phase were observed to have similarity with those in over-spread and atomized powders produced under similar processing conditions. The microstructural features observed with variation in spray conditions are discussed in detail.
关键词:
Spray deposition
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null
,
null
,
null
Jiuzhou ZHAO
材料科学技术（英文）
Modeling and simulation have been carried out for Al-Pb alloys to investigate the Brownian coagulation effect on the microstructure development in a gas-atomized drop during the liquid-liquid decomposition. The results indicate that Brownian coagulation has a weak effect on the nucleation and a relatively strong effect on coarsening the minority phase droplets. The influence of Brownian coagulation on the liquid-liquid decomposition decreases with the increase in the diameter (or the decrease in the cooling rate) of the atomized drop.
关键词:
Immiscible alloy
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null
,
null
,
null
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null
