FeAl(Si)多孔材料的制备及高温力学性能

研究以Fe、Al、Si元素粉末为原料,采用粉末冶金法,通过偏扩散/反应烧结制备FeAl(Si)多孔材料。采用X射线衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)、多孔性能测试和高温拉伸实验等分析测试手段,研究FeAl(Si)多孔材料在烧结过程中的孔结构演变、显微组织形貌和高温力学性能。结果表明,在烧结过程中,随温度升高,孔隙数量增多,孔径增大,经1 120℃保温2 h后得到了具有孔结构丰富,孔隙均匀分布,单一FeAl(Si)相的多孔材料,该材料孔隙度为51.0%,最大孔径为27.3μm,透气度为373.7 m^3/(h·kPa·m^2)。随温度由室温升高,FeAl(Si)多孔材料的抗拉强度先升高后降低,500℃时,FeAl(Si)多孔材料表现出最大的抗拉强度15.24 MPa,温度进一步升高,抗拉强度急剧下降。低温下FeAl(Si)多孔材料表现为脆性断裂,高温下呈现出一定的塑性断裂特征。

Preparation and high temperature mechanical property of porous FeAl(Si) material

FeAl(Si) porous material was prepared by powder metallurgy method by partial diffusion/reaction sintering with Fe,Al and Si element powders as raw materials. The pore structure,microstructure and high temperature mechanical properties of FeAl(Si) porous material were investigated by XRD,SEM,EDS,porous performance tester and heat-strength tensile testing machine. The results show that the number of pores and pore size increased significantly with the increasing temperature. The pores were rounded and evenly distributed after sintering,and a single FeAl(Si) phase was obtained after sintering at 1 120 ℃. The open porosity of the prepared FeAl(Si) porous material was 51.0%,the maximum pore size was 27.3 μm,and the air permeability was 373.7 m 3/(h·kPa·m 2). The high temperature mechanical properties of the FeAl(Si) porous material increased first and then decreased with temperature increasing gradually from room temperature. When the temperature was 500 ℃,the FeAl(Si) porous material exhibited the maximum tensile strength of 15.24 MPa. While further increasing the temperature,the tensile strength decreased sharply. By studying the morphologies of the fractures surfaces,it was brittle fracture at low temperatures and plastic fracture at high temperatures.