Joining of Diamond Grains to Medium Carbon Steel with Ni-Base Powder during Laser Brazing
In order to develop new generation brazed Diamond grinding wheels, the joining experiments of Diamond super abrasive grains and medium carbon steel using the powder mixture of Ni-Cr alloy as active brazing alloy are carried out via laser in an argon atmosphere. The relevant characteristics of the special powder mixture, the microstructure of the interfacial region, which are both the key factors for determining the joining strength among the Diamond grains, the filler layer and the steel substrate, are investigated extensively by means of scanning electron microscope (SEM) and energy dispersion spectrometer (EDS), as well X-ray diffraction (XRD) analysis. The formation mechanism of carbide layers was discussed. All the results indicate that high strength bonding between diamond grits and the steel substrate has been successfully realized because the chromium in the Ni-based alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product Cr3C2, and the bond between the alloy and the Diamond was established through the reaction product.
Bo Zhao, Guanglin Wang, Wei Ma, Zhibo Yang and Yanyan Yan
Z. B. Yang et al., "Joining of Diamond Grains to Medium Carbon Steel with Ni-Base Powder during Laser Brazing", Key Engineering Materials, Vol. 455, pp. 392-396, 2011