恒温时间对PCD复合片高频感应钎焊性能影响研究  

Study of influence of holding time on weld property in hi-frequency induction brazing of polycrystalline diamond compact

作　　者：贾乾忠[1] 张弘弢[1] 李嫚[1] 董海[1] 

机构地区：[1]大连理工大学机械工程学院,辽宁大连116024

出　　处：《大连理工大学学报》2013年第3期370-375,共6页Journal of Dalian University of Technology

摘　　要：采用AgZnCuMnNi钎料高频感应钎焊聚晶金刚石复合片(PDC)与硬质合金,研究了690℃钎焊温度下不同恒温时间对其钎焊性能的影响.利用扫描电镜、电子探针、X射线衍射仪等对钎缝界面和聚晶金刚石(PCD)层的热损伤进行了分析,并测试了钎缝抗剪强度.结果表明:钎缝内主要存在Ag基固溶体、Cu基固溶体、Cu0.64Zn0.36相和少量MnNi相,恒温时间15s时,含Cu基固溶体、Cu0.64Zn0.36相和MnNi相的灰黑色晶粒对钎缝起到弥散强化作用,钎缝抗剪强度达最大值350.6MPa;随着恒温时间的延长,灰黑色晶粒平均等积圆直径逐渐变大,钎缝边界形成连续金属间化合物层,抗剪强度下降;PCD层的热损伤随钎焊中恒温时间的延长而加剧,生产中应采用较短的恒温时间.A AgZnCuMnNi filler metal is applied to join polycrystalline diamond compact （PDC） onto a cemented carbide substrate, using brazing temperature 690 ℃ and different holding time. The microstructure and phase composition of joints are investigated by means of scanning electron microscopy, electron probe micro-analysis and X-ray diffraction. The thermal damage layer of polycrystalline diamond （PCD） is also observed using scanning electron microscopy, while the bond strength of joints is determined by shear testing. The microstructural investigations reveal that Ag（s. s）, Cu（s. s）, Cu0.64Zn0.36 and a small amount of MnNi phases appear at the joint interface. The max shear strength of 350. 6 MPa is determined in samples joined at 15 s, which is partially due to dispersion strengthening of gray-black grains which contain Cu（s. s）, Cu0.64 Zn0.36 and MnNi phases in the joints. Equal-area-circle grain diameter of the gray-black grains grows with longer holding time, whereas the shear strength decreases because of the formation of continuous intermetallic compounds layer along the joint boundary. In addition, the thermal damage of the PCD layer deteriorates with the increasing of holding time, and shorter holding time is preferable in the production.

关 键 词：聚晶金刚石复合片 恒温时间 剪切强度 钎焊接头 热损伤 

分 类 号：TG454[金属学及工艺—焊接]