Pakistan's FAKhalid et al. used the method of brazing in a vacuum furnace to study the microstructure of the diamond interface with Cu-14.4Sn-10.2Ti-1.5Zr alloy as the brazing filler metal. Brazing process: vacuum degree 2×10-8Pa, brazing temperature 930°C, holding time 10min, cooling rate 20°C/min. Scanning electron microscopy and X-ray energy spectrum analysis showed that the titanium carbide formed at the diamond-solder interface had a two-layer structure, the first layer was a cubic TiC, and the second layer was a slender or cylindrical TiC.
Meng Weiru of Xi'an Jiaotong University used the method of brazing in a vacuum furnace to test the adaptability of diamond brazing filler metal. Three kinds of BNi2 (NiCrSiB), BNi7 (NiCrP) and self-made CuSnNiTi brazing filler metals containing strong carbide forming elements Cr and Ti were used respectively, and the respective brazing temperatures were 1050 ° C, 950 ° C and 900 ° C, respectively, and the holding time was 10 min. And a single layer brazed diamond circular saw blade (φ125 mm) under a vacuum of 0.13 Pa. Scanning electron microscopy observation of morphology and X-ray energy spectrum analysis showed that the three solders have good wettability to diamond. The Cr and Ti elements in the solder will diffuse to the diamond surface and C element in the diamond. Combines to form carbides. The formation of carbides causes a chemical-metallurgical bond between the diamond, the brazing filler metal and the matrix, which improves the holding power of the diamond, but the bonding condition and the sawing performance vary with the brazing filler metal. The test confirmed that the self-made copper-based solder has a low brazing temperature, the thermal damage of the diamond during brazing is small, and the diamond has a good holding power, and the brazing material has good adaptability to the cut stone, and effectively improves the hardness. Utilization of diamonds. Taiwan University used Cu-15Ti-10Sn alloy brazing filler metal to compare the effects of brazing method (brazing temperature 925 ° C, heat preservation 5 min) and laser brazing method (brazing time 10 seconds) on the microstructure of diamond interface. Under the brazing condition in the vacuum furnace, a continuous transition layer (TiC film) is formed on the surface of the diamond; and under the condition of laser brazing, a discontinuous transition layer is formed on the surface of the diamond.
The above studies show that different solder alloys (including solder composition, content, state, etc.), brazing methods and brazing process parameters directly affect the interaction between the solder and the matrix and diamond, the form of the product and Combines the microstructure of the interface to affect the bond strength and the quality and performance of the brazing tool