(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 以Mn、Si元素粉末为原料，用反应合成方法制备Mn-Si金属间化合物多孔材料，表征各烧结温度所对应的孔结构、膨胀率和微观形貌，研究烧结过程中孔隙产生的机理。结果表明：在Mn-Si金属间化合物多孔材料的制备过程中烧结体发生明显的体积膨胀，烧结温度在800 ℃之前时膨胀率和开孔隙率随着温度的升高不断增大，800 ℃以后，膨胀率和开孔隙率均呈下降趋势；在最终烧结温度1040 ℃下得到开孔隙率为47.60%、平均孔径为11.97 μm、孔结构均匀的多孔材料。探讨多孔材料的造孔机理，主要为压制孔隙的演变，成型剂的脱除，以及Mn元素和Si元素在扩散反应中不同扩散速度引起的Kirkendall效应。
关键字: Mn-Si；多孔材料；金属间化合物；造孔机理
（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
