摘要
研究了气泡形核及长大对Gasar气孔结构和分布的影响。结果表明:气孔在柱状晶过渡区内生长时,其定向生长受限使气孔的长度变短,内壁不光滑,圆整度变小;当基体以柱状晶生长时气孔随基体共生生长形成典型藕状多孔结构,气孔的长度增加,内壁光滑,圆整度增加。随着气体压力的增大形核功降低导致气泡形核率增加,从而使藕状多孔Cu中气泡的分布逐渐从晶界转移到晶内,试样的平均孔径减小而气孔的密度数和均匀性提高。由于固液界面上的沟槽和晶界的特殊性,气泡在晶界处的形核优先于晶内,导致晶界处气孔的平均直径比晶内气孔的直径大。
The effect of pore nucleation,pore growth and solidification mode of matrix on pore structure and distribution of lotus-type porous Cu were investigated. It is difficult to obtain an ordered pore structure when the matrix is a region of columnar transition. An ordered pore structure could be obtained only when the matrix transforms to columnar grains with increase of pore length and circularity. The pore distribution moved from the grain boundaries to the interior of grain with increasing gas pressure. The average pore diameter decreased and the pore density increased due to decrease of activation energy and increased rate of nucleus formation. Due to slight depressions at grain boundaries regions at the solid/liquid interface, the pore nucleation is favored at grain boundaries and thus the average pore diameter in the grain boundaries is larger than that of in the grains.
作者
李飞
李再久
田娟娟
谢明
朱绍武
陈家林
LI Fei LI Zaijiu TIAN Juanjuan XIE Ming ZHU Shaowu CHEN Jialin(City College, Kunming University of Science and Technology, Kunming 650051, China Aviation College, Kunming University of Science and Technology, Kunming 650500, China State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming lnstitute of Precious Metals, Kunming 650106, China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2017年第9期641-649,共9页
Chinese Journal of Materials Research
基金
贵金属先进材料协同创新中心协同创新基金(2014XT03)
稀贵金属综合利用新技术国家重点实验室开放课题(SKL-SPM-201545)~~
关键词
金属材料
Gasar
藕状多孔Cu
凝固模式
形核
长大
metallic materials, Gasar, lotus-type porous Cu, solidification model, pore nucleation,pore growth
