摘要
以Fe55耐磨合金粉末为基础,通过添加不同含量的25%NiCr-75%Cr_(3)C_(2)粉末,制备了铁基复合合金粉末,并采用激光直接沉积的方法,在Q235钢基板上制备不同含量Cr_(3)C_(2)的铁基复合涂层。利用OM、SEM、XRD、显微硬度测试、摩擦磨损实验、高温氧化性实验及电化学工作站等分析手段,分析比较了各沉积涂层的组织与性能。结果表明,添加Cr_(3)C_(2)的复合涂层主要由α-Fe、γ-Fe、Cr_(7)C_(3)、(Cr,Fe)_(7)C_(3)、Cr_(23)C_(6)、CrFeB和Cr_(3)C_(2)等相组成。在添加30%(质量分数)Cr_(3)C_(2)的涂层中出现了以Cr_(3)C_(2)颗粒为中心向周边辐射的长杆状和多边形块状(Cr,Fe)_(7)C_(3)的典型放射状组织,并且放射状组织中三种碳化物的形成先后顺序是Cr_(3)C_(2)→(Cr,Fe)_(7)C_(3)→Cr_(23)C_(6)。Cr_(3)C_(2)的添加增加了共晶组织的数量,改变了共晶组织的形态。未添加Cr_(3)C_(2)的涂层中共晶组织约占40.2%(体积分数),而添加30%Cr_(3)C_(2)的涂层中共晶组织达到50.6%(体积分数);添加9%Cr_(3)C_(2)的涂层共晶组织明显细化,片层间距明显减小。与Fe55涂层相比,添加9%、15%和30%(质量分数)Cr_(3)C_(2)的三种涂层的硬度、耐磨性、高温抗氧化性及耐腐蚀性均显著提高,而添加15%Cr_(3)C_(2)的涂层的综合性能最佳。本研究提出的Cr_(3)C_(2)增强Fe55合金涂层的方法有望为研发激光增材制造高硬度、耐磨损和耐腐蚀等的摩擦零件工作层提供新途径。
In this study,the Fe-based composite alloy powders were obtained by mechanically(ball-milling)mixing different amounts of 25%NiCr-75%Cr_(3)C_(2) powders with Fe55 wear-resistant alloy powders.And then,using the prepared composite alloy powders,Fe-based composite coa-tings with different Cr_(3)C_(2) contents were subsequently fabricated on Q235 steel substrates via laser direct deposition.The microstructure and properties of the deposited coatings were analyzed using many experimental means such as OM,SEM,XRD,microhardness test,friction and wear test,high temperature oxidation test and electrochemical workstation,and so on.The results showed that,the composite coatings containing Cr_(3)C_(2) are mainly composed of α-Fe,γ-Fe,Cr_(7)C_(3),(Cr,Fe)_(7)C_(3),Cr_(23)C_(6),CrFeB and Cr_(3)C_(2),etc.The coating with 30%Cr_(3)C_(2) exhibits ty-pical radial structures which constitute of long rod-shaped and polygon block(Cr,Fe)_(7)C_(3) radiating from the center of Cr_(3)C_(2) particles to the perip-hery,and the chronological formation sequence of the three carbides in the radial structure is Cr_(3)C_(2)→(Cr,Fe)_(7)C_(3)→Cr_(23)C_(6).Moreover,the addition of Cr_(3)C_(2) can result in the increase of the amount of eutectic structure and the change in morphology,as the coatings with no/with 30% Cr_(3)C_(2) contains about 40.2%/50.6%eutectic structure,and the eutectic structure of the coating with 9%Cr_(3)C_(2) is obviously refined,with a remarkably smaller lamellar spacing.Compared with Fe55 coating,all the composite coatings(with 9%,15%and 30% Cr_(3)C_(2))got significantly improved in comprehensive mechanical properties such as hardness,wear resistance,high temperature oxidation resistance and corrosion resistance,and the coating with 15% Cr_(3)C_(2) has the best integrative performance.The strengthening method for directly deposited Fe55 alloy coatings by adding Cr_(3)C_(2) proposed in this work is expected to provide new insights for the development of laser-additive manufacturing high-hardness,wear resistant and corrosion resistant working layer of friction parts.
作者
尹桂丽
陈岁元
梁京
刘常升
YIN Guili;CHEN Suiyuan;LIANG Jing;LIU Changsheng(Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education,Key Laboratory for Laser Application Technology and Equipment of Liaoning Province,School of Materials and Engineering,Northeastern University,Shenyang 110819,China;School of Material Science and Engineering,Liaoning University of Technology,Jinzhou 121001,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第10期10127-10133,共7页
Materials Reports
基金
国家重点研发计划项目课题(2016YFB1100201)
工信部绿色系统集成项目(2017-53)
沈阳市新兴产业研发计划项目(18-004-2-26)。
