无造孔剂模压烧结制备多孔Cu_(60)Zn_(40)合金的工艺及组织调控

Effect of Preparation Methods on Pore Structure and Zinc Volatilization of Porous Cu_(60)Zn_(40) Alloy

金属多孔材料在制备过程中通常需要掺杂造孔剂以调控孔隙结构,但去除造孔剂需要较长时间,且残留造孔剂会对母材造成污染或腐蚀。以水雾化Cu_(60)Zn_(40)合金粉末为原材料,在未掺杂造孔剂条件下,采用单轴限位模压和烧结工艺制备了多孔Cu_(60)Zn_(40)合金,深入研究了高度压缩比和烧结时间对其孔隙结构的影响。研究结果表明,在未掺杂造孔剂的情况下,粉末冶金制备的多孔Cu_(60)Zn_(40)合金的孔隙结构主要受压制条件和烧结工艺控制。随着压坯高度压缩比从1.6增加至2.0,多孔Cu_(60)Zn_(40)合金的孔隙率降低了48.15%,同时最大孔径、平均孔径和最小孔径分别减小了45.51%、46.72%和66.43%。尽管孔隙形貌未发生明显变化,但该调控方式有效改变了合金的孔隙尺寸。随着烧结时间延长,多孔Cu_(60)Zn_(40)合金的孔隙形状明显趋于球形化,而孔隙率和孔隙尺寸变化幅度较小。因此,采用模压烧结法制备的多孔Cu_(60)Zn_(40)合金,可通过调整高度压缩比灵活调控开孔隙率和孔隙尺寸,可通过调控烧结时间优化孔隙形貌。此外,在多孔Cu_(60)Zn_(40)合金的烧结过程中,锌的挥发量与高度压缩比成反比,与烧结时间成正比。本研究为无掺杂造孔剂调控金属多孔材料孔隙结构提供了可靠的理论和技术支持,对粉末冶金制备金属多孔材料具有重要理论和实际意义。

During the preparation process of metal porous materials,it is usually necessary to add pore-forming agents to regulate the pore structure.However,the removal of pore-forming agents takes a long time,and the residual pore-forming agents may contaminate or corrode the parent material.The impact of height compression ratio and sintering time on the pore structure of porous Cu_(60)Zn_(40)alloy,prepared through uniaxial limited-pressure sintering without the addition of pore-forming agents,was thoroughly investigated.The findings reveal that the pore structure of the porous Cu_(60)Zn_(40)alloy,fabricated via powder metallurgy without the addition of a pore-forming agent,is predominantly governed by the pressing conditions and sintering process.Elevating the compression ratio of the green compact height from 1.6 to 2.0 results in a substantial 48.15%reduction in porosity.Correspondingly,there is a notable decrease in maximum,average,and minimum pore diameters by 45.51%,46.72%,and 66.43%,respectively,with no significant alterations in pore morphology.Increasing the sintering time induces a shift towards more spherical pore shape,accompanied by pore shrinkage and modest adjustments in open porosity and pore size for the porous Cu_(60)Zn_(40)alloy.Thus,the powder metallurgy approach for fabricating porous Cu_(60)Zn_(40)alloy for the fine-tuning of open porosity and pore size by manipulating the height compression ratio,while optimizing pore morphology can be achieved through adjustments in sintering time.Furthermore,the zinc volatilization during sintering of the porous Cu_(60)Zn_(40)alloy exhibits an inverse correlation with the high compression ratio and a direct correlation with the sintering time.This study provides reliable theoretical and technical support for the regulation of pore structure in metal porous materials without the addition of pore-forming agents,which is of significant theoretical and practical importance in the field of powder metallurgy for preparing metal porous materials.