Effect of heat treatment on the microstructure,mechanical properties and fracture behaviors of ultra-high-strength SiC/Al-Zn-Mg-Cu composites  

作　　者：Guonan Ma Shize Zhu Dong Wang Peng Xue BolüXiao Zongyi Ma 

机构地区：[1]Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]Centre of Excellence for Advanced Materials,Dongguan 523808,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第10期2233-2243,共11页矿物冶金与材料学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2022YFB3707405);the Guangdong Basic and Applied Basic Research Foundation,China(No.2021A1515110525);the National Natural Science Foundation of China(Nos.U22A20114 and 52301200);the Liaoning Revitalization Talents Program,China(No.XLYC2007009)。

摘　　要：A high-zinc composite,12vol%SiC/Al-13.3 Zn-3.27 Mg-1.07Cu(wt%),with an ultra-high-strength of 781 MPa was success-fully fabricated through a powder metallurgy method,followed by an extrusion process.The effects of solid-solution and aging heat treat-ments on the microstructure and mechanical properties of the composite were extensively investigated.Compared with a single-stage sol-id-solution treatment,a two-stage solid-solution treatment(470℃/1 h+480℃/1 h)exhibited a more effective solid-solution strengthen-ing owing to the higher degree of solid-solution and a more uniform microstructure.According to the aging hardness curves of the com-posite,the optimized aging parameter(100℃/22 h)was determined.Reducing the aging temperature and time resulted in finer and more uniform nanoscale precipitates but only yielded a marginal increase in tensile strength.The fractography analysis revealed that intergranu-lar cracking and interface debonding were the main fracture mechanisms in the ultra-high-strength SiC/Al-Zn-Mg-Cu composites.Weak regions,such as the SiC/Al interface containing numerous compounds and the precipitate-free zones at the high-angle grain boundaries,were identified as significant factors limiting the strength enhancement of the composite.Interfacial compounds,including MgO,MgZn2,and Cu5Zn8,reduced the interfacial bonding strength,leading to interfacial debonding.

关 键 词：metal matrix composites heat treatment interfacial reaction mechanical properties fracture mechanism 

分 类 号：TB333[一般工业技术—材料科学与工程] TG156[金属学及工艺—热处理]