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在0.6 MPa纯H2气氛中,采用金属/H2共晶定向凝固(Gasar)技术制备得到Gasar多孔Cu-x Cr合金。研究了Cr含量、凝固模式以及凝固速率对Gasar多孔合金气孔结构和显微组织的影响。结果表明,当合金以平面、胞状及柱状枝晶凝固时,Gasar多孔Cu-x Cr合金能获得定向生长气孔。当凝固方式转变为等轴枝晶凝固时,定向生长气孔发生中断。Gasar多孔Cu-x Cr合金(x=0.8%、1.3%)气孔在共晶相前沿析出,与共晶组织协同定向生长。随Cr含量增加,共晶组织体积百分比增加,孔隙率和孔圆整度进一步增加;随多孔Cu-1.3 Cr合金试样凝固高度增加,凝固速率下降,界面生长方式转变为等轴晶生长方式,则无法得到定向生长气孔。
Gasar porous Cu-xCr alloy was prepared by metal / H2 eutectic solidification (Gasar) in a 0.6 MPa pure H2 atmosphere. The effects of Cr content, solidification mode and solidification rate on the pore structure and microstructure of Gasar porous alloy were investigated. The results show that Gasar porous Cu-xCr alloy can obtain directional growth pores when the alloy is solidified by planar, cellular and columnar dendrites. When the solidification mode transforms into equiaxed dendrite coagulation, the directional growth of pores stalled. Gasar porous Cu-xCr alloy (x = 0.8%, 1.3%) stomatal precipitation in the eutectic phase, co-crystal structure and eutectic growth. With the increase of Cr content, the volume percentage of the eutectic structure increases and the porosity and hole roundness further increase. With the increase of the solidification height of the porous Cu-1.3 Cr alloy sample, the solidification rate decreases and the interfacial growth mode changes to the equiaxed crystal growth mode. You can not get directional growth pores.