高体积分数SiCp/7075Al复合材料的时效析出行为  

Aging Behavior of High Volume Fraction SiCp/7075Al Composites

作　　者：刘冀念[1,2] 董蓉桦 刘炎[3] 刘永星[3] 

机构地区：[1]中国航天员科研训练中心,北京100094 [2]北京理工大学材料科学与工程学院,北京100081 [3]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《材料科学与工程学报》2016年第3期357-361,共5页Journal of Materials Science and Engineering

摘　　要：高体积分数SiC颗粒增强7系铝基复合材料(SiCp/7XXXAl)具有高比强度比刚度等特点,因此适宜作为结构件在航空航天、汽车等领域应用。本文采用压力浸渗法制备了45vol.%的SiCp/7075Al复合材料,并对复合材料和基体合金的时效行为进行了系统的研究。DSC分析结果发现复合材料的η′相和η相的放热峰分别比基体7075合金降低了4.4℃和0.5℃。复合材料与7075铝合金达到峰时效的时间均为9h,峰时效时复合材料与基体7075铝合金的硬度分别提高了38.7%(从213.4到296HB)和107.6%(从98.2到203.9HB)。颗粒的加入使得基体中的位错密度显著增加,这有利于析出相的形核。但另一方面,合金元素在界面的偏聚会抑制析出相的析出。因此,SiCp/7075Al复合材料的析出行为是两方面共同作用的结果。High volume fraction SiC particle reinforced 7XXX alloy composites（SiCp/7XXXAl）are suitable for application as structural component in aerospace and automobile industries,due to their high specific strength and specific stiffness.In this paper,45 vol.% SiCp/7075 Al composite was prepared by pressure infiltration method.The microstructure and aging behavior of Al alloy matrix and composite were investigated systematically.DSC results show that the exothermic peak ofη′andηin composites are reduced by4.4℃ and 0.5℃ relative to 7075 alloy,respectively.The time to reach the aging peak for SiCp/7075 Al composite and 7075 alloy was the same（9hrs）.At the aging peak,the hardness of SiCp/7075 Al composite and7075 alloy have been increased by 38.7%（from 213.4to 296HB）and 107.6%（from 98.2to 203.9HB）respectively.It is believed that addition of SiC particles to high volume fraction makes the dislocation density of matrix increase significantly,which thus can accelerate the nucleation of precipitate.On the other hand,the segregation of alloying elements may inhibit the precipitation during aging treatment.Therefore,the aging behavior of the SiCp/7075 Al composite is a comprehensive effect of the above two aspects.

关 键 词：TG金属基复合材料 时效 析出 超强铝合金 力学性能 

分 类 号：TB333[一般工业技术—材料科学与工程]