金刚石与磨料磨具工程2025，Vol.45Issue(1)：56-66,11.DOI:10.13394/j.cnki.jgszz.2024.0026
钎焊工艺对钎焊金刚石界面组织和性能的影响
Effect of brazing process on microstructure and properties of brazed diamond interface
摘要
Abstract
Objectives:Diamond tools are widely used in various fields.Copper-based brazing materials are used for brazing diamond tools.In response to the problems of low-temperature phase flow and low bonding strength of copper-based brazing materials at high temperatures,different brazing temperatures and brazing times are designed,and the WC/Cu-Sn-Ti composite brazing material is used for vacuum induction brazing to study the changes in microstructure and mechanical properties of brazed joints.Methods:The brazing samples were made of HWD40 diamond with a particle size code of 35/40,a 45 steel matrix,and WC/Cu-Sn-Ti composite brazing filler metal.The vacuum degree was 1×10-3 Pa,the brazing temperature were 950,980,1 010,1 040 and 1 070℃,and the brazing time was 10,15,20 and 25 min,respectively.The SEM observation and XRD phase analysis were carried out on different samples after brazing.At the same time,friction and wear tests were carried out on brazing samples at different temperatures and different holding times to obtain the grinding amount and diamond drop rate of the samples,so as to analyze the mechanical prop-erties of the joint structures.Results:(1)Under the conditions of a brazing temperature of 980℃and a holding time of 15 min,the line scan analysis is conducted on the elements at the brazed diamond interface.It is found that the W ele-ment is enriched near the brazed diamond interface,possibly due to the diffusion of elements in WC.The XRD phase analysis showes the formation of TiC and W2C compounds at the diamond interface,which can improve the wettability between the diamond and brazing material,and enhance the adhesion of the brazing material to the diamond.In order to further determine the formation of TiC,the sample is subjected to aqua regia etching,and the surface of the diamond particle is analyzed by SEM and EDS to determine that the TiC is formed by the metallurgical reaction between the act-ive element Ti and the C element on the diamond surface.(2)To investigate the effect of the brazing process on the sur-face morphology of brazed diamond,the morphology of the diamond surface is analyzed at different brazing temperat-ures with a holding time of 15 minutes.It is found that the diamond surface has obvious pores and cracks at a brazing temperature of 950℃.When the brazing temperature is raised to 980℃,the cutting edge of the diamond remaines in-tact,and the diamond is exposed the most.As the brazing temperature continues to rise,the diamond graphitization phe-nomenon in the brazed sample becomes severe.Therefore,the brazing process with a holding time of 15 minutes and a brazing temperature of 980℃has the best effect.(3)Raman analysis is performed on the samples at 950,1 010,and 1 070℃to calculate the ratios of the diamond peak and graphite peak in the samples.It is found that when the temperat-ure increases from 950℃to 1 070℃,the temperature increases by 12%,and the degree of graphitization of diamond increases by 90%.At the same time,when the brazing temperature is 980℃,the main wear form of the diamond is flat and micro-damage,and the diamond shedding rate is 0.(4)To further compare the effect of insulation time on the per-formance of brazed joints,friction and wear tests are conducted on samples with different insulation times at the optim-al brazing temperature of 980℃.It is found that as the insulation time increases,the number of diamond drops in-creases from 0 to 3.However,if the insulation time is too long,the diamond particles suffer thermal damage.When the brazed sample with an insulation time of 15 minutes is used to grind marble,the marble grinding volume of the sample is 36.154 mm3,and the grinding performance of the sample is the best.Conclusions:The compound layer at the inter-face between the diamond particles and the WC/Cu-Sn-Ti composite brazing is uniform,continuous and dense.A thin and continuous layered TiC and a small amount of W2C phase are formed on the surface of diamond particles,which im-proves the bonding strength between the diamond and steel substrate.Under the conditions of a brazing temperature of 980℃and a holding time of 15 min,the friction coefficient of diamond particles in the grinding process is small,the grinding amount of the marble workpiece is large,and the diamond particle shedding rate is low.By reasonably con-trolling the brazing temperature and holding time,the efficiency and quality of diamond-abrasive tools in the processing of marble and other materials can be improved,the shedding rate of diamond particles can be reduced,and the service life of abrasive tools can be extended.At a brazing temperature of 980 ℃ and a holding time of 15 minutes,the dia-mond particles exhibit a low friction coefficient during the grinding process,a high grinding volume on marble work-pieces,and a low diamond drop-out rate.By controlling the brazing temperature and holding time,the efficiency and quality of diamond grinding tools in processing materials such as marble can be improved,reducing the diamond particle drop-out rate and extending the tool's service life.The WC/Cu-Sn-Ti brazing material was used for vacuum brazing of diamond.The effects of brazing temperature and holding time on the morphology,the interfacial structure,and mechanical properties of brazed diamond were studied using a scanning electron microscope,X-ray diffractometer,energy spectrum analysis,and shear and grinding experiments.The results show that the compound layer formed at the composite brazing interface between diamond particles and WC/Cu-Sn-Ti is uniform,continuous and dense,and a thin and continuous layered TiC and a small amount of W2C phases are formed on the surface of diamond particles,which improves the bonding strength between the diamond and steel matrix.As the brazing temperature increases and the holding time prolongs,the interface defects of brazing gradually decrease,and the degree of diamond graphitization in-creases.Under the brazing temperature of 980℃and a holding time of 15 minutes,the friction force and the coefficient of friction of diamond particles during the grinding process are relatively small,resulting in the largest grinding volume for the marble workpiece and the lowest detachment rate of diamond particles.关键词
Cu-Sn-Ti钎料/钎焊工艺/力学性能/金刚石磨具Key words
Cu-Sn-Ti brazing material/brazing process/mechanical properties/diamond grinding tool分类
化学工程引用本文复制引用
崔冰,姜雪,杜全斌,徐凡,严佩佩,王蕾,张黎燕..钎焊工艺对钎焊金刚石界面组织和性能的影响[J].金刚石与磨料磨具工程,2025,45(1):56-66,11.基金项目
河南省高校重点科研项目(24A460008) （24A460008）
河南省重点研发与推广专项科技攻关项目(242102220064,241111231600). （242102220064,241111231600）
