Ti-C含量对多孔TiC/FeAl复合材料孔型结构和力学性能的影响  

Effects of Ti-C contents on the pore structures and mechanical properties of porous TiC/FeAl composites

作　　者：迟静[1] 李敏[1] 王淑峰[1] 吴杰[1] CHI Jing;LI Min;WANG Shufeng;WU Jie(School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学材料科学与工程学院,青岛266590

出　　处：《复合材料学报》2018年第9期2503-2511,共9页Acta Materiae Compositae Sinica

基　　金：山东省自然科学基金(ZR2014EMM009)

摘　　要：以尿素为造孔剂,利用自蔓延高温合成技术制备了多孔TiC/FeAl复合材料,主要考察了Ti-C含量(质量分数为15wt%~35wt%)对多孔TiC/FeAl复合材料孔型结构和压缩性能的影响。当Ti-C含量不高于25wt%时,多孔TiC/FeAl复合材料由毫米孔和孔壁微孔组成规则的复合孔型结构。相互连通的毫米孔产生于尿素颗粒的挥发和液相迁移;微孔尺寸为10~50μm,产生于Fe-Al-Ti-C粉末的自蔓延过程,孔径随Ti-C含量的增加而增大。通过调整尿素的体积分数,多孔TiC/FeAl复合材料的孔隙率可控制在56.64%~85.35%。当Ti-C含量不高于25wt%时,多孔TiC/FeAl复合材料的抗压强度随Ti-C含量的增加而增大。当Ti-C含量高于25wt%时,多孔TiC/FeAl复合材料壁面微孔形状很不规则,且抗压强度下降。孔隙率约为64.3%时,多孔Fe-Al金属间化合物和TiC/FeAl复合材料(Ti-C含量为25wt%)的抗压强度分别为20.03MPa和66.68MPa,对应的应变值分别为4.77%和8.21%。另外,多孔TiC/FeAl复合材料的压缩性能可用Gibson-Ashby模型来解释。The porous TiC/FeAl composites were fabricated by using carbamide as apace-holders via self-propagating high-temperature synthesis（SHS）.The effects of Ti-C contents（mass fraction：15 wt%-35 wt%）on the pore structures and compressive behaviors of the porous TiC/FeAl composites were investigated.When Ti-C content is not more than 25 wt%,the porous TiC/FeAl composites exhibit composite pore structures composed of millimeter pores and micro pores dispersed in pore walls.The interconnected millimeter pores originate from the volatilization of carbamide particles and the migration of liquid phases,while the micro pores are formed during the SHS process of the Fe-Al-Ti-C powders,the pore size（10-50μm）of micro pores increases with increasing Ti-C content.Depending on the volume fraction of the carbamide,the porosity of the porous TiC/FeAl composites can be controlled in a range of 56.64%-85.35%.When Ti-C mass fraction is not more than 25 wt%,the compressive strength of porous TiC/FeAl composites increases with increasing Ti-C content.When Ti-C mass fraction is higher than25 wt%,the morphology of micro pores becomes very irregular,and the compressive strength decreases.As the porosity is about 64.3%,the compressive strengths of porous Fe-Al and porous TiC/FeAl composite with 25 wt% TiC are 20.03 MPa and 66.68 MPa,corresponding strains are 4.77% and 8.21%,respectively.Furthermore,the compressive behavior of porous TiC/FeAl composites can be understood by the Gibson-Ashby model.

关 键 词：Ti-C 多孔TiC/FeAl 自蔓延高温合成 孔型结构 压缩性能 

分 类 号：TB333[一般工业技术—材料科学与工程]