CuNiSnTi钎料钎焊立方氮化硼界面产物分析

Analysis on interfacial products of the joint of cubic boron nitride brazed to CuNiSnTi filler metal

采用扫描电镜、能谱仪、微区X射线衍射仪研究了Cu Ni Sn Ti活性钎料钎焊立方氮化硼（c-BN）界面产物的微观结构和形成机理,并运用动力学分析了界面反应产物的生长过程及反应激活能.结果表明,钎焊过程中CuNi Sn Ti钎料对c-BN具有良好的润湿性,钎料与c-BN发生化学反应,实现c-BN与钢基体的可靠连接;钎料与c-BN界面处生成Ti-N和Ti-B化合物新相,形成了钎料/Ti N/Ti B/Ti B2/c-BN的结构形式;在钎焊温度1 323∽1 398 K,保温时间5∽20 min之间依据抛物线生长法则指出界面处产生的化学反应和原子间的相互扩散是促使界面反应层形成与生长的主要因素及形成机理.

The microstructure and formation mechanism of the products in the interface of the joint of c-BN brazed to CuNiS nT i filler metal were investigated by scanning electron microscope（ SEM）,energy dispersion spectrometer（ EDS）,as well as micro X-ray diffraction（ XRD）. Also,the growth process and diffusion activation energy of the interfacial reaction products were deeply studied with a kinetics theory. The results showed that the CuN iS nT i filler metal exhibited a good wettability on c-BN in the brazing. And the reaction between filler metal and c-BN occurred,therefore the reliable connection between c-BNand steel substrate was realized. The new phase of Ti-N and Ti-B compounds were found in the interface between filler metal and cBN. Then the formed structure of the interface was in the form of filler / TiN / TiB / TiB 2 / c-BN. The growth process of reaction layer depends mainly on the inter-diffusion among the atoms and chemical reaction generated at the interface in the brazing temperature of 1 153- 1 193 K for 5- 20 min following a parabolic rule.