发泡参数对粉末冶金制备泡沫铝显微组织和压缩性能的影响（英文）

Effects of foaming parameters on microstructure and compressive properties of aluminum foams produced by powder metallurgy method

使用廉价CaCO_3作为发泡剂,采用粉末压块熔炼工艺制备单胞间具有通道的半开孔泡沫铝。将铝和CaCO_3粉末混合物冷压缩成在空气气氛和一定温度下发泡的致密圆柱形前驱体。研究前驱体压缩压力、发泡剂含量、发泡温度和发泡时间对所得泡沫铝显微组织、线膨胀率、相对密度和压缩性能的影响。结果表明,所得泡沫铝的显微组织分布均匀,晶粒尺寸小于100μm,具有半开孔结构,相对密度为55.4%~84.4%%。随着压缩压力(127~318)的增大,当发泡剂含量为15%(质量分数)时,泡沫铝的线膨胀率、压缩强度和紧实应变增大。当发泡温度从800°C升高到1000°C时,除压缩强度和相对密度外,泡沫铝的其他参数都增大。研究结果表明,最佳发泡温度和发泡时间分别为900°C和10~25 min。

Semi open-cell aluminum foams having channels between individual cells were produced using low cost CaCO3foamingagent and applying the powder compact melting process.To this end,the aluminum and CaCO3powder mixtures were coldcompacted into dense cylindrical precursors for foaming at specific temperatures under air atmosphere.The effects of severalparameters including precursor compaction pressure,foaming agent content as well as temperature and time of the foaming processon the cell microstructure,linear expansion,relative density and compressive properties were investigated.A uniform distribution ofcells with sizes less than100μm,which form semi open-cell structures with relative densities in the range of55.4%-84.4%,wasobtained.The elevation of compaction pressure between127-318MPa and blowing agent up to15%(mass fraction)led to anincrease in the linear expansion,compressive strength and densification strain.By varying the foaming temperature from800to1000°C,all of the investigated parameters increased except compressive strength and relative density.The results indicated theoptimal foaming temperature and time as900°C and10-25min,respectively.