SiC_(p)尺寸对铸态AZ91镁合金显微组织与腐蚀性能的影响  

Effect of SiC_(p)Size on Microstructure and Corrosion Properties of Cast AZ91 Mg-alloys

作　　者：吕鑫 邓坤坤[1,2] 王翠菊 聂凯波[1] 史权新[1] 梁伟[1,2] LV Xin;DENG Kunkun;WANG Cuiju;NIE Kaibo;SHI Quanxin;LIANGWei(School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of Interface Science and Engineering in Advanced Materials,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]太原理工大学先进材料界面科学与工程教育部重点实验室,太原030024

出　　处：《中国腐蚀与防护学报》2023年第1期135-142,共8页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(52001223,51771128和51771129)。

摘　　要：采用半固态搅拌铸造方法制备出亚微米SiC_(p)增强AZ91复合材料(S1)、微米SiC_(p)增强AZ91复合材料(M10)以及双尺度SiC_(p)增强AZ91复合材料(S1+M9)。利用OM、SEM、XRD、浸泡法、电化学测试等研究了不同尺寸SiC_(p)对铸态AZ91镁合金显微组织与腐蚀性能的影响。结果表明,SiC_(p)的添加可以显著细化AZ91镁合金中半连续网状Mg17Al12相,这归因于SiC_(p)对Mg17Al12相的异质形核作用。Mg17Al12相能够包裹亚微米SiC_(p)析出,并且可以依附微米SiC_(p)表面析出。通过对比含有相同SiC_(p)体积分数的S1+M9和M10,可以看出S1+M9的耐蚀性相比M10显著降低,表明当SiC_(p)含量一定时,SiC_(p)的尺寸从微米变为亚微米会导致AZ91镁合金的耐蚀性降低。The sub-micron SiC_(p),micron SiC_(p) and dual-scale SiC_(p) reinforced AZ91 Mg-alloy based composites,namely composites(S1),(M10),and(S1+M9)respectively,were prepared by semi-solid stirring casting method.They were then characterized by means of optical microscope,scanning electron microscope,X-ray diffraction,immersion method,and electrochemical test,etc in terms of the effect of the particle size of SiC_(p) on the microstructure and corrosion properties of the as-cast AZ91 Mg-alloys.The results show that the addition of SiC_(p) can refine significantly the semi-continuous network-like Mg_(17)Al_(12) phase in the AZ91 Mg-alloy,which is attributed to the heterogeneous nucleation effect of SiC_(p)on the Mg_(17)Al_(12) phase.The Mg_(17)Al_(12) phase can be precipitated as Mg_(17)Al_(12) particles with core of sub-micron SiC_(p),and/or directly on the surface of micron SiC_(p).By comparing the two composites reinforced with the same volume fraction of SiC_(p),it can be found that the corrosion resistance of S1+M9 is significantly lower than that of M10,indicating that when the content of SiC_(p) is constant,changing the size of SiC_(p) from micron to sub-micron will reduce the corrosion resistance of the composites.

关 键 词：AZ91镁合金 SiC_(p) 显微组织 腐蚀性能 

分 类 号：TG174[金属学及工艺—金属表面处理]