Form and Distribution Characterization of Reaction Products at the Brazing Interface Between Ni-Cr Alloy and Diamond

摘要

In order to reveal the size, number, form and distribution characterization of resultant at the brazing diamond interface using Ni-Cr alloy, vacuum furnace brazing was carried out. SEM-EDS microanalyses have shown that during brazing the chromium present in the alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product. X-ray diffraction revealed that the wetting and bonding behaviour on diamond surface by molten Ni-Cr alloy is realized through Cr_3C_2 and Cr_7C_3 which are produced by interaction between Cr atoms of Ni-Cr alloy and C atoms of diamond surface at elevated temperatures. Furthermore, the size, number, form and distribution characterization of Cr_3C_2 and Cr_7C_3 were discovered and the brazing mechanism for diamond was illuminated.