Nucleation and Growth of Cr₇C₃ of Brazing Diamond with Ni-Cr Alloy in Protective Atmosphere Furnace

Abstract

Mono-crystal diamond was brazed with Ni-Cr alloy in protective atmosphere furnace, SEM and XRD were used to analyze the carbides on the surface of diamond and the phases of diamond after brazing, respectively. The results show that the diamond brazed in protective atmosphere furnace can realize high strength connection; the diamond has clear edges and complete morphology after brazing. On the surface of diamond, the arrangement of Cr3C2 is regular, the growth direction of Cr3C2 has a certain orientation relationship with the (111) crystal plane of diamond, all the Cr7C3 nucleates and grows on the surface of Cr3C2, finally, the inner layer is regular arrangement Cr3C2 and the external layer is Cr7C3.

Research and Development of Powder Brazing Filler Metals for Diamond Tools: A Review

“…Cr would concentrate near the surface of the diamond, and reacts with C, subsequently forming Cr 3 C 2 and Cr 7 C 3 . In turn, this becomes the key factor in achieving solid bonding [27][28][29]. The main phenomenon involving an interfacial bonding mechanism for steel and diamond, using a Ni-Cr alloy, is the cross-diffusion of Ni, Cr, and Fe between the brazing alloy and the steel substrate [21].…”

“…Cr would concentrate near the surface of the diamond, and reacts with C, subsequently forming Cr3C2 and Cr7C3. In turn, this becomes the key factor in achieving solid bonding [27][28][29].…”