石墨烯改性Ni-Cr合金激光钎焊金刚石界面组织与力学性能研究  

Interface Structure and Mechanical Properties of Laser-brazed Diamond of Graphene-modified Ni-Cr Alloy

作　　者：崔长春 李奇林[1] 谈志东 单大平 丁凯[1] 韩锦锦 葛源 CUI Changchun;LI Qilin;TAN Zhidong;SHAN Daping;DING Kai;HAN Jinjin;GE Yuan(Jiangsu University of Technology,Jiangsu Changzhou 213001,China;Aecc Aviation Power Co.,Ltd.,Xi'an 710021,China;Meltron Metal Surface Technology(Changzhou)Co.,Ltd.,Jiangsu Changzhou 213164,China)

机构地区：[1]江苏理工学院,江苏常州213001 [2]中国航发动力股份有限公司,西安710021 [3]熔创金属表面科技(常州)有限公司,江苏常州213164

出　　处：《表面技术》2025年第7期109-117,共9页Surface Technology

基　　金：国家自然科学基金(51905234);江苏省高等学校自然科学研究重大项目(22KJA460004);江苏省基础研究计划自然科学基金项目(BK20220692);江苏省研究生科研与实践创新计划(SJCX23_1635)。

摘　　要：目的针对采用Ni-Cr合金制备钎焊金刚石砂轮时金刚石表面石墨化严重、内应力较大等热损伤问题,采用不同含量的石墨烯改性Ni-Cr合金,制备钎焊金刚石试样,研究石墨烯含量对激光钎焊金刚石界面组织及力学性能的影响。方法采用同轴送粉末法制备石墨烯改性钎焊金刚石试样,并分析质量分数为0.00%、0.01%、0.02%、0.03%的石墨烯改性钎焊金刚石试样的界面组织、物相、显微硬度、金刚石石墨化程度及金刚石颗粒的残余应力等,同时在相同工艺条件下制备不添加金刚石的石墨烯改性钎焊试样,并研究石墨烯改性钎焊层的耐磨性能。结果金刚石表面与钎料的界面处存在显著的元素相互扩散现象,其中Cr元素在金刚石附近明显偏析,界面反应生成的片状化合物主要为Cr_(3)C_(2)。随着石墨烯含量的增加,界面区域的C、Cr元素明显减少,金刚石石墨化程度及残余应力降低。钎焊层晶粒明显细化。钎焊层的显微硬度由866.6HV逐步上升到1119.0HV,平均摩擦因数从0.71降至0.61,磨损体积从4.03×10^(-2)mm^(3)降至1.86×10^(-2)mm^(3)。测试结果显示,当石墨烯的质量分数为0.03%时,钎焊金刚石石墨化程度及残余应力较低,且钎焊层具有更好的晶粒结构、耐磨性及更高的显微硬度。结论在镍铬钎料中适量添加石墨烯,将降低钎焊金刚石石墨化程度及残余应力等,提高钎焊层的显微硬度和摩擦磨损性能。Compared with electroplated diamond grinding wheel and sintered diamond grinding wheel,the brazed diamond grinding wheel has the characteristics of high bonding strength,large grits exposure,and high grinding performance,which is widely used in the grinding of engineering ceramics,optical glass,etc.However,thermal damage such as graphitization and residual stress will occur during the brazing of diamond with Ni-Cr alloy,which reduces the grinding performance of the brazed diamond grinding wheels remarkably.In order to solve this problem,the work aims to investigate the effect of the graphene addition on the interface structure and mechanical properties of laser-brazed diamond.ANSI 1045 steel with size of 100 mm×35 mm×10 mm was used as the matrix,Ni-Cr powder was evenly mixed with graphene powder of different mass fractions,i.e.0.00%,0.01%,0.02%and 0.03%separately.The graphene-modified Ni-Cr alloy was then mixed with diamond by ball milling according to the mass ratio of 7∶1.The samples were prepared on the matrix by laser brazing based on coaxial-powder feeding method.The brazed samples were tested and analyzed with SEM,XRD,Laser Raman spectroscopy,Vickers hardness tester,etc.The results showed that there was significant element diffusion at the interface between the diamond surface and the brazing alloy,and the width of diffusion layer was about 2μm,in which the concentration distribution of Cr in the interface region was relatively high,and the Cr element was obviously segregated near the diamond grit.The flake compound formed by the interface reaction was mainly Cr_(3)C_(2).With the increase of graphene content,due to its large specific surface area and excellent adsorption capacity,the reaction between the C element on the diamond surface and the Cr element in the brazing alloy was inhibited and reduced and the C and Cr elements in the interface region were significantly reduced.The carbides formed by the reaction at the interface between the diamond and the brazing metal were significantly reduced,and t

关 键 词：激光钎焊 石墨烯 金刚石 微观组织 热损伤 耐磨性 

分 类 号：TG425[金属学及工艺—焊接]