无压渗透法制备Al/AlN复合材料及其性能  

Fabrication and properties of Al/AlN composites by a pressureless infiltration process

作　　者：俞雨[1,2] 程继贵[1,2] 万磊[1,2] 梁槟星[1] 刘君武[1,2] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]安徽省粉末冶金工程技术研究中心,合肥230009

出　　处：《复合材料学报》2011年第6期166-171,共6页Acta Materiae Compositae Sinica

基　　金：安徽省自然科学基金(090414187);国家特种显示工程中心资金项目(042301D2)

摘　　要：在常压下通过熔渗工艺将AlSi7Mg合金渗入由AlN粉末模压成形、预烧所获得的预烧结坯中,得到了不同Al含量的Al/AlN复合材料。采用X射线衍射仪对复合材料的相组成进行了测试,采用金相显微镜和SEM对其显微组织进行了观测,并对不同Al含量的Al/AlN复合材料的维氏硬度、抗弯强度、热膨胀系数及导热系数等进行了测试分析。结果表明:在900℃下,N2气氛中通过熔渗工艺可以制备出相对密度高于98.5%的Al/AlN复合材料,且在整个制备过程中AlN坯体尺寸几乎没有变化;Al/AlN复合材料的硬度和强度随Al含量的增加而降低,导热系数和热膨胀系数则随Al含量增加有所增加;Al体积分数为38%和62%时,Al/AlN复合材料维氏硬度分别为HV 715和HV 203,抗弯强度分别为492MPa和388MPa,室温导热系数分别为73W/(m.K)和120W/(m.K),室温至200℃的平均线膨胀系数分别为8.60×10-6 K-1和1.11×10-5 K-1;Al/AlN复合材料的热膨胀系数与Al含量的关系符合Kerner模型。Al/AlN composites with different Al content were prepared by infiltrating AlN preforms with molten AISi7Mg alloy. Phase composition of the composites was characterized by XRD. Microstructure of the composites was observed by optical microscope and SEM. Mechanical and thermal properties of the composites with different Al content were also tested. The results show that Al/AlN composites with relative density of more than 98.5% can be obtained by infiltrating the AlN preforms with different porosity at 900℃ in N2 atmosphere. There is nearly no shape and dimension change of AlN preforms during the infiltration process. The mechanical and thermal properties of the composites vary with Al content. As Al volume fraction varies from 38% to 62%, the Vickers hardness of the composites decreases from HV 715 to HV 203, the bending strength decreases from 492 MPa to 388 MPa, the room temperature thermal conductivity of the composites increases from 73 W/（m K） to 120 W/（m K）, and the mean linear thermal expansion coefficient （TEC） between room temperature and 200 ~C varies from 8.60× 10-6 K-1 to 1. 11×10-5 K-1. The results also show that the relation between the TEC and A1 volume fraction of the composites agrees with the Kerner model.

关 键 词：AlN多孔坯体 Al/AlN复合材料 无压渗透 力学性能 热学性能 

分 类 号：TB333[一般工业技术—材料科学与工程]