真空烧结Fe-Al多孔材料的元素挥发及其对孔结构的影响  

Elemental evaporation and its effect on pore structure in porous Fe-Al alloys' vacuum sintering

作　　者：陈刚[1] 沈培智[1] 高海燕[1] 贺跃辉[1] 黄伯云[1] 徐南平[2] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]南京工业大学膜科学技术研究所,南京210009

出　　处：《粉末冶金材料科学与工程》2010年第3期229-235,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(20636020);国家自然科学基金委员会创新研究群体科学基金资助项目(50721003);国家杰出青年科学基金资助项目(50825102)

摘　　要：以Fe、Al元素混合粉末为原料,采用粉末冶金法,通过偏扩散/反应合成—烧结,制备Fe-Al金属间化合物多孔材料。根据烧结前后多孔试样的质量变化,并结合XRD、SEM、EDS等测试手段,对烧结过程中多孔试样基础元素挥发行为及孔结构变化进行研究。结果表明,真空烧结元素粉末制备Fe-Al多孔材料过程中,最终烧结温度为1 000℃、保温4 h时,Fe-Al多孔试样质量损失率为0.05%,而最终烧结温度为1300℃时质量损失率达到10.53%;随着最终烧结温度升高,合金元素沿孔壁表面挥发程度增大,导致Fe-Al多孔试样的孔径、开孔隙率和透气度变大。采用MIEDEMA模型和LANGMUIR方程,对真空烧结过程中的质量损失原因进行理论分析,表明Al的挥发是导致多孔试样的质量和孔结构变化的主要原因。Porous Fe-Al alloy has been prepared by powder metallurgy through partial diffusion and reactive synthesis using Fe、Al mixture powder as raw materials.The mass and final pore structure changes of porous Fe-Al were characterized by the XRD,SEM,EDS,etc.The results show that the mass loss rate is 0.05% at the final sintering temperature of 1 000 ℃,while it is 10.53% at 1 300 ℃ both holding for 4 h.The pore size,open porosity and permeability of porous Fe-Al increase with the increasing of sintering temperature and the elemental evaporation is stronger along with surfaces of pore walls.Based on the MIEDEMA model and LANGMUIR equation,the reason for elemental evaporation during vacuum sintering was analyzed through calculation.The main reason for the mass loss of porous Fe-Al is that Al evaporates intensely during sintering,which leads to the mass and pore structure changes of porous Fe-Al.

关 键 词：真空烧结 金属间化合物 FE-AL 多孔材料 挥发 

分 类 号：TG146[一般工业技术—材料科学与工程]