(1. 武漢東湖學(xué)院，機電工程學(xué)院，武漢 430212；
2. 武漢理工大學(xué)，現(xiàn)代汽車零部件技術(shù)湖北省重點實驗室，武漢 430070；
3. 哈爾濱工業(yè)大學(xué)，材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 為了滿足航空航天領(lǐng)域?qū)Ω呷埸c開孔泡沫金屬的迫切需求，針對現(xiàn)有開孔泡沫金屬熔點低、強度和抗氧化性能差，以及孔隙率低、孔徑結(jié)構(gòu)分布不均勻等難題，以三維網(wǎng)狀開孔泡沫Ni為基體，采用固體粉末包埋結(jié)合高溫固相擴散工藝，制備出一種孔隙率達到95%三維網(wǎng)狀開孔Ni-Cr-Fe泡沫合金。利用掃描電鏡(SEM/EDS)對開孔Ni-Cr-Fe泡沫合金化前后的組織形貌和元素擴散進行分析，進一步了解擴散過程中Ni-Cr-Fe骨架形成與元素擴散之間的規(guī)律，并且對合金化后泡沫合金的微觀形貌及結(jié)構(gòu)進行表征。同時，研究了800 ℃和1000 ℃條件下開孔Ni-Cr-Fe泡沫合金的準靜態(tài)壓縮性能和能量吸收性能。結(jié)果表明：隨著高溫固相擴散時間的延長，網(wǎng)絲骨架中Cr、Fe、Ni元素濃度梯度明顯平緩，(1200 ℃, 48 h)均勻化熱處理后，網(wǎng)絲骨架中Cr、Fe、Ni 3種元素發(fā)生了充分的互擴散，達到合金成分均勻化。并且，開孔Ni-Cr-Fe泡沫合金保持著初始泡沫Ni基體的三維網(wǎng)狀及骨架中空結(jié)構(gòu)。同時，高溫壓縮時開孔Ni-Cr-Fe泡沫合金具有典型韌性金屬泡沫的變形特性，其壓縮強度隨著泡沫合金中Cr、Fe含量的增加而明顯增大，而能量吸收性能表現(xiàn)出先增加后降低的趨勢。
關(guān)鍵字: 開孔泡沫金屬；固體粉末包埋工藝；高溫固相擴散工藝；合金化；力學(xué)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
