(1. 武汉东湖学院，机电工程学院，武汉 430212；
2. 武汉理工大学，现代汽车零部件技术湖北省重点实验室，武汉 430070；
3. 哈尔滨工业大学，材料科学与工程学院，哈尔滨 150001)
摘 要: 为了满足航空航天领域对高熔点开孔泡沫金属的迫切需求，针对现有开孔泡沫金属熔点低、强度和抗氧化性能差，以及孔隙率低、孔径结构分布不均匀等难题，以三维网状开孔泡沫Ni为基体，采用固体粉末包埋结合高温固相扩散工艺，制备出一种孔隙率达到95%三维网状开孔Ni-Cr-Fe泡沫合金。利用扫描电镜(SEM/EDS)对开孔Ni-Cr-Fe泡沫合金化前后的组织形貌和元素扩散进行分析，进一步了解扩散过程中Ni-Cr-Fe骨架形成与元素扩散之间的规律，并且对合金化后泡沫合金的微观形貌及结构进行表征。同时，研究了800 ℃和1000 ℃条件下开孔Ni-Cr-Fe泡沫合金的准静态压缩性能和能量吸收性能。结果表明：随着高温固相扩散时间的延长，网丝骨架中Cr、Fe、Ni元素浓度梯度明显平缓，(1200 ℃, 48 h)均匀化热处理后，网丝骨架中Cr、Fe、Ni 3种元素发生了充分的互扩散，达到合金成分均匀化。并且，开孔Ni-Cr-Fe泡沫合金保持着初始泡沫Ni基体的三维网状及骨架中空结构。同时，高温压缩时开孔Ni-Cr-Fe泡沫合金具有典型韧性金属泡沫的变形特性，其压缩强度随着泡沫合金中Cr、Fe含量的增加而明显增大，而能量吸收性能表现出先增加后降低的趋势。
关键字: 开孔泡沫金属；固体粉末包埋工艺；高温固相扩散工艺；合金化；力学性能
（1. School of Mechanical and Electrical Engineering, Wuhan Donghu University, Wuhan 430212, China;
2. Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070, China;
3. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:In order to meet the requirements of the high melting point open-cell foams in aerospace applications and in view of the problems existed in open-cell foams with the low-melting point, poor strength and oxidation resistance, low porosity and uneven distribution of pore, the 3D reticulated Ni-Cr-Fe alloy foams with 95% porosity were synthesized by co-deposition of chromium and iron onto open-cell nickel foams. Then the open-cell Ni-Cr-Fe foams were homogenized by the high-temperature solid-phase diffusion. To understand the rule between Ni-Cr-Fe skeleton formation and element diffusion behavior, the microstructure and elemental analysis of the open-cell Ni-Cr-Fe alloy foams were conducted by scanning electron microscopy (SEM) and energy spectrum diffraction (EDS) before and after homogenized. At the same time, the quasi-static compression and energy absorption performance of the open-cell Ni-Cr-Fe alloy foams were studied at 800 ℃ and 1000 ℃, respectively. The results show that the Cr, Fe and Ni concentration gradients are smooth along the strut thickness, when the diffusion time of high temperature solid phase is extended. The struts of open-cell Ni-Cr-Fe alloy foams are homogenized after heat treatment at 1200 ℃ for 48 h. As compared with the open-cell Ni foam, the Ni-Cr-Fe alloy foams keep the original reticulated structure. At the same time, the Ni-Cr-Fe alloy foams show the deformation characteristics of typical ductile metal foams in the high temperature compression test. With the increase of Cr and Fe contents in the alloy foams, the compression strengths of the open-cell Ni-Cr-Fe alloy foams increase and the energy absorption performances first increase and then decrease.
Key words: open-cell metal foam; pack cementation process; high-temperature solid-phase diffusion; alloying; mechanical properties
