摘要
在Mg2Si增强的AZ91镁基复合材料试样上首先预制疲劳裂纹,然后在疲劳载荷的作用下向试样裂纹尖端渗注纳米CeO2/Ni-P复合镀液,采用SEM、EDS及XRD表征了沉积产物的形貌和结构,探讨了产物的沉积行为对镁基复合材料疲劳裂纹扩展的影响规律。结果表明,试验所用镁基复合材料的疲劳门槛值约为1.8 MPa.m1/2,纳米复合镀液能在镁基复合材料的裂纹尖端形成层片状膜层,并且膜层中的纳米CeO2颗粒分散均匀。复合镀液的沉积起到了明显的延滞裂纹扩展的作用,可以在高于镁基复合材料疲劳门槛值的载荷下使裂纹不扩展。
Pre-fatique crack was performed on Mg2Si/AZ91 composites samples at first, and then nano-CeO2/Ni-P electroless bath was dropped into the crack tips of the composites samples under fatigue loading. Microstructure, components and phases of the Ni-P deposits layer were analyzed by SEM, EDS and XRD, respectively. The effect of the deposition behavior on fatigue crack growth of the composites was discussed. Results show that the threshold value of Mg matrix composite materials is about 1.8 MPa-m1/2. A lamellar Ni-P deposition layer with uniform distribution of nano-CeO2 particles are deposited in the fatigue crack tips, which plays a significant role in preventing the crack propagation under a higher load than the fatigue threshold of the Mg2Si/AZ91 composites.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第1期16-20,共5页
Transactions of Materials and Heat Treatment
基金
南京工程学院校级科研基金项目(KJB201203)
南京工程学院创新基金项目(CKJ2011002)
关键词
镁基复合材料
复合化学镀
疲劳裂纹
疲劳门槛值
Mg matrix composite materials
electroless composite plating
fatigue crack
threshold value of fatigue
