摘要
在落管中进行Cu-Co合金的快速凝固试验,分析了液滴尺寸与合金成分对微观组织演变过程的影响。结果表明,液滴尺寸越小,其内部的富Co粒子越弥散;Co含量越接近亚稳液态组元不混溶区的临界成分,合金熔体越容易发生液-液相变,凝固组织中富Co粒子平均半径越大。液-液相变过程中富Co相液滴在液滴内部形核,并在温度梯度作用下向液滴中心高温区做Marangoni迁移,这最终导致在粉末表面形成贫Co层。
The effects of size and concentration of droplet on the microstructure of rapidly solidified Cu-Co alloy in drop-tube have been investigated.The experimental results demonstrate that Co-rich particle in the droplet becomes more dispersive with the decrease of the droplet size.With Co concentration approaching towards the critical composition of metastable miscibility region,the liquid-liquid phase transformation is easier to be created in the molten alloy,and the average radius of Co-rich particle becomes bigger and bigger in the solidified microstructure.Co-rich particle is nucleated in the droplet and taken Marangoni movement towards high temperature region in center of droplet with temperature gradient during liquid-liquid phase transformation,resulting in the formation of Co-poor on the surface of the powder.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2006年第10期626-628,共3页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(50371092
50395104)
辽宁省自然科学基金资助项目(20050047)
