王雪
,
李言祥
,
刘源
金属学报
利用金属/气体共晶二维定向凝固的方法制备出放射状多孔金属. 凝固过程中, 气孔的
生成使熔体体积膨胀, 从而导致凝固界面前沿出现剧烈的熔体流动. Mg-H系实验结果显示, 横向对
流会影响气孔的生长方向, 促进气泡逸出以及降低气孔分布的均匀性. 通过合理的铸型结构设计以及
选择适当的工艺参数, 可以将剧烈而有害的横向对流限制至一个较低的程度, 从而制得高质量的气孔
均匀分布的放射状多孔镁.
关键词:
二维定向凝固
,
Porous metal
,
Metal/gas eutectic
,
Convection
Yuan LIU
材料科学技术（英）
The effect of gas pressures on the mean pore size, the porosity and the pore size distribution of lotus-type porous magnesium fabricated with Gasar process were investigated. The theoretical analysis and the experimental results all indicate that there exists an optimal ratio of the partial pressures of hydrogen pH2 to argon pAr for producing lotus-type structures with narrower pore size distribution and smaller pore size. The effect of solidification mode on the pore size distribution and pore size was also discussed.
关键词:
Porous metal
,
null
,
null
X.L.Gong
,
Y.Liu
,
S.Y.He
,
J.Lu
材料科学技术（英）
Three types of metal porous polymer composite (MPPC) were produced by infiltrating different polymers into a porous Al structure. This type of interpenetrating microstructure allows for a better combination of mechanical and physical properties. The low velocity impact response of these composites was investigated by conducting drop-weight impact tests. Impact parameters such as the peak load, the time to peak load, the deflection at peak load, and the absorbed energy were evaluated and compared for Al, MPPC and pure Al foam. The influence of the volume fraction of polymer was also investigated for the above impact parameters. The experimental results indicate that the inlaid polymer has a very important positive effect on the impact behavior and improves the characteristics of the composite in comparison with conventional foam and pure Al.
关键词:
MPPC
,
null
,
null
