利用SPS烧结Cu-Al合金去合金化制备多孔铜工艺研究

Research on Preparing Nanoporous Copper by Dealloying Using SPS Sintering Cu-Al Alloy

金属多孔材料由于兼具结构材料和功能材料的特性,在催化、过滤、热交换、燃料电池、传感、储能和生物电化学等方面有着广泛的应用前景,是近些年来的研究热点。目前多孔金属的制备面临着所得材料孔径较大且分布不均的问题,这使其使用场合受到限制。因此,制备孔隙较小且分布均匀的多孔铜具有重要意义。本实验对Cu15Al85、Cu30Al70成分原料进行放电等离子烧结,烧结温度400℃,烧结压力分别为10 MPa、20 MPa和30 MPa,制备出两种Al-Cu合金前驱体。前驱体随后在0.5 mol/L、1.0 mol/L和1.5 mol/L三种不同浓度盐酸中进行去合金化,获得的多孔铜材料成分、形貌、微观结构等利用扫描电子显微镜、能谱仪进行观察和分析。研究表明,Cu15Al85原料粉在30 MPa烧结压力下获得的前驱体外观体积最小,材料最致密,随后的去合金化速率最小;1.5 mol/L的盐酸对Cu-Al前驱体中Al的去除率最高,且表现出最快的腐蚀速度;同一盐酸浓度下去合金化,Cu15Al85比Cu30Al70体现出更低的腐蚀速率,获得孔隙尺寸较大且孔隙率较高的多孔铜。

Porous metal materials have broad application prospects in catalysis, filtration, heat exchange, fuel cell, sensing, energy storage and bioelectrochemistry due to their characteristics of both structural and functional materials. The preparation of porous copper is one of the hot topics in recent years. Therefore, it is important to prepare porous copper with small pores and uniform distribution. In this experiment, two types of nano Cu-Al powder, Cu15Al85 and Cu30Al70, were turned into Al-Cu alloy cylinders with SPS sintering technique under the pressure of 10 MPa, 20 MPa, and 30 MPa respec-tively. Three different concentrations of hydrochloric acid (0.5 mol/L, 1.0 mol/L, and 1.5 mol/L re-spectively) were used to finish the dealloying. The composition, morphology and microstructure of porous copper were observed and analyzed by SEM and EDS. The experiment results show that the precursor obtained under the pressure of 30 MPa has the smallest size, highest density, and the rate of dealloying is lowest. The removal ratio and corrosion rate of Al in the precursor dealloying in hydrochloric acid of 1.5 mol/L are highest. Comparing with the Cu30Al70, the precursor sintered from powder of Cu15Al85 has lower corrosion rate in the same concentration of hydrochloric acid, and po-rous copper with larger size pores and higher porosity was obtained consequently.