藕状多孔Cu-2%Zn合金气孔协同基体的生长行为

Growth Behavior of Pore Collaborative Matrix of Lotus-Type Porous Cu-2%Zn Alloys

在氢气的高压气氛中,利用连铸法制备了藕状多孔Cu-2%Zn合金。为研究气孔协同基体的生长行为,对合金进行了金相显微组织分析。结果表明:大多数沿着柱状晶晶界生长的气孔,平均孔径和长度都很小;大多数生长在柱状晶晶内的气孔,平均孔径和长度都较大。沿晶界生长的气孔会受到柱状晶彼此淘汰现象的干扰和柱状枝晶臂的阻碍。生长在晶界的气孔数量少于晶内,主要原因是气孔在晶界形核机会相对晶内很少。

Lotus-type porous Cu-2% Zn alloys were fabricated by continuous casting technique at various withdrawal rates. The microstructure of porous alloy was investigated. The results show that the average pore diameter and length of most pores growing along grain boundary of columnar crystal is smaller than those grow in grain. Selection phenomenon of columnar crystal and dendrite arms can hinder the growth of pore along grain boundary. The number of pores that grow along grain boundary is less than that in grain. The main reason is that the opportunity of pore nucleation on grain boundary is less than that in grain.