Isothermal sections in the Cr-Ga-N system in the 650-1000 deg. C temperature range

摘要

Isothermal sections at 670, 740, and 800 deg. C in the Cr-Ga-N ternary system were investigated. Details of the Cr-Ga and Cr-N binary phase diagrams were confirmed, and the equilibrium diagrams were constructed. At all temperatures, Cr_3GaN was in equilibrium with all the condensed phases, except GaN. In the 670-800 deg. C temperature range, Cr_2GaN appears to be kinetically stable in contact with GaN. This led to the construction of behavior diagrams that are valid only as long as GaN is present in the initial mixture. Above ≈ 9l0 deg. C, Cr_2GaN decomposes to form Cr_3GaN, CrN, and Ga(l). At l000 deg. C, Cr_3GaN is in equilibrium with all the condensed phases, and CrN is in equilibrium with Ga.