Al2O3@Y3Al5O12纳米短纤维对铝合金基复合材料的增强作用  

Enhancement effect of Al2O3@Y3Al5O12 short nanofibers on aluminum alloy matrix composites

作　　者：何玲[1,2] 刘晨光 李文生[1] 孙卫民[1] 潘莉莉 HE Ling;LIU Chenguang;LI Wensheng;SUN Weimin;PAN Lili(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《复合材料学报》2020年第2期400-407,共8页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51674130);沈阳材料科学国家研究中心-有色金属加工与再利用国家重点实验室联合基金(18LHPY006);甘肃省重点研发计划(17 JR7GA014)

摘　　要：采用一种具有芯-壳结构的复合纳米纤维增强铝合金复合材料,可以在提高抗拉强度的同时增加塑性。通过真空热压烧结技术制备了Al2O3@Y3Al5O12复合纳米短纤维增强2024铝合金复合材料。研究了纤维添加质量分数对复合材料致密度、硬度、抗拉强度及延伸率的影响;并探究了芯-壳结构在复合材料增韧中的作用。结果表明:Al2O3@Y3Al5O12纳米短纤维具有良好的分散性,在超声分散及机械搅拌混粉后均匀吸附在铝合金颗粒表面,无分层及团聚现象;经热压烧结后, Al2O3@Y3Al5O12纳米短纤维以短纤维形态均匀分散在铝合金基体内,少量添加Al2O3@Y3Al5O12纳米短纤维起到了桥联和孔洞填充作用,使复合材料致密度和硬度提高;添加质量分数为1wt%时,抗拉强度和延伸率取得最大值,由铝合金的249.3 MPa、 2.9%增加到299.1 MPa、 4.3%。Al2O3@Y3Al5O12纳米短纤维的添加可以细化晶粒,阻碍裂纹扩展,且在拔出/断过程中Al2O3@Y3Al5O12纳米短纤维芯-壳结构的塑性变形起到了增强增韧作用。By using a kind of composite nanofibers with core-shell structure to reinforce aluminum alloy matrix composites, it can improve the tensile strength while increasing plasticity. Al2O3@Y3Al5O12 short nanofibers reinforced 2024 aluminum alloy composites were prepared by vacuum hot-pressing sintering technique. The effects of Al2O3@Y3Al5O12 nanofibers content on the relative density, hardness, tensile strength and elongation of composites were studied, and the effect of the core-shell structure on the toughening mechanism of the composites explored. The results show that the Al2O3@Y3Al5O12 short nanofibers have good dispersion, and the fibers are uniformly adsorbed on the surface of aluminum alloy particles without stratification and agglomeration was method of ultrasonic dispersion and mechanical agitation. After hot-pressing sintering, the Al2O3@Y3Al5O12 short nanofibers are uniformly dispersed in the aluminum alloy matrix with a form of short fibers, and a small content of Al2O3@Y3Al5O12 short nanofibers plays the role of bridging and hole filling, which increases the relative density and hardness of the composites. There are the maximum tensile strength and elongation of the composites at the nanofiber mass fraction of 1 wt%, which increase from 249.3 MPa(matrix) to 299.1 MPa, 2.9%(matrix) to 4.3%, respectively. The addition of Y3Al5O12-Al2O3 short nanofibers can refine the composites grain, hinder crack propagation, and the plastic deformation of Y3Al5O12-Al2O3 core-shell structure plays a strengthening and toughening effect in the process of pulling out/breaking.

关 键 词：铝合金复合材料 Al2O3@Y3Al5O12复合纳米纤维 抗拉强度 延伸率 芯-壳结构 

分 类 号：TB331[一般工业技术—材料科学与工程]