摘要
对离心铸造Al-8.5Ni-xSi复合材料铸件的微观组织进行了观察,研究了Si含量对复合材料的组织、硬度和耐磨性的影响。结果表明:Al-8.5Ni-9Si铸件的外层偏聚了较多的初生NiAl3颗粒,内层为无颗粒的基体层;而Al-8.5Ni-14Si,Al-8.5Ni-19Si铸件则形成了具有大量初生NiAl3/Si颗粒的外层增强层,中间无颗粒的基体层以及含有较多初生Si/NiAl3颗粒的内层增强层的三层组织。随着Si含量由9%(质量分数,下同)增加到14%,19%,Al-8.5Ni-xSi铸件增强层的初生NiAl3/Si颗粒体积分数逐渐增大,材料的硬度及耐磨性逐渐增强。在离心场中,初生NiAl3的离心运动与初生Si的向心运动是形成Al-8.5Ni-xSi铸件不同组织的主要原因。
The microstructures of the centrifugal composites Al-8.5Ni-xSi tubes were observed.Effects of Si content on the microstructures,hardness and wear-resistance of the tubes were investigated.The results show that the Al-8.5Ni-9Si tube consists of an outer layer containing some primary NiAl3 and the inner layer of Al matrix.While the Al-8.5Ni-14 Si,Al-8.5Ni-19 Si tubes both have an outer layer segregating many primary NiAl3 and Si particles,the middle layer having no particles and the inner layer containing a few primary NiAl3 and Si particles.The particle volume fractions in the reinforcement layer of the Al-8.5Ni-xSi tubes increase gradually as well as the hardness and the wear resistance with the Si content increasing from 9%（mass fraction,the same below）to 14%and 19%.The centrifugal migration of NiAl3 and the centripetal movement of Si in the centrifugal field play an important role in the formation of the Al-8.5Ni-xSi tubes which have various structures.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2015年第2期53-60,共8页
Journal of Materials Engineering
