(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 以Mn、Si元素粉末為原料，用反應(yīng)合成方法制備Mn-Si金屬間化合物多孔材料，表征各燒結(jié)溫度所對(duì)應(yīng)的孔結(jié)構(gòu)、膨脹率和微觀形貌，研究燒結(jié)過(guò)程中孔隙產(chǎn)生的機(jī)理。結(jié)果表明：在Mn-Si金屬間化合物多孔材料的制備過(guò)程中燒結(jié)體發(fā)生明顯的體積膨脹，燒結(jié)溫度在800 ℃之前時(shí)膨脹率和開孔隙率隨著溫度的升高不斷增大，800 ℃以后，膨脹率和開孔隙率均呈下降趨勢(shì)；在最終燒結(jié)溫度1040 ℃下得到開孔隙率為47.60%、平均孔徑為11.97 μm、孔結(jié)構(gòu)均勻的多孔材料。探討多孔材料的造孔機(jī)理，主要為壓制孔隙的演變，成型劑的脫除，以及Mn元素和Si元素在擴(kuò)散反應(yīng)中不同擴(kuò)散速度引起的Kirkendall效應(yīng)。
關(guān)鍵字: Mn-Si；多孔材料；金屬間化合物；造孔機(jī)理
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Porous Mn-Si material was prepared by reactive synthesis, and the pore structure, expansion rate and microscopic morphologies were characterized, and the mechanism of pore formation in the sintering process was investigated. The results show that the volume of compact increases significantly during the reactive synthesis process. When the sintering temperature is below 800 ℃, the expansion and the open porosity increase with increasing the sintering temperature. However, both the expansion and the open porosity begin to decrease after the temperature rising to 800 ℃. After being sintered at 1040 ℃, a porous material is obtained with a porosity of 47.60%, an average pore size of 11.97 μm, and a uniform pore structure. The main pore formation mechanisms are evolvement of interparticle pores, removal of binder and the Kirkendall effect due to the difference in diffusion rates of Mn and Si.
Key words: Mn-Si; porous material; intermetallics; pore formation mechanism
