Thermophysical properties and deposition of B2 structure based Al-Ni-Ru-M alloys

Thermal expansion coefficients (i) increase with temperature, (ii) are similar to those of superalloys and steels, and (iii) are mostly dependent on Ru content. A fused and subsequently pulverized Al-Ni-Ru B2 alloy was deposited on a Ni-based superalloy substrate made of modified CMSX-4 using vacuum and atmospheric plasma spraying. The coatings obtained were characterized for their microstructure, phase composition, hardness, and bond strength. The coatings exhibited sound microstructural integrity and favorable coating-substrate adhesion. The phases originally present in the powder were also found to be retained in the coating. Interdiffusion processes between the investigated coatings and the Ni-based superalloy substrate were primarily estimated by the diffusion couples approach. The segregation of a new intermetallic phase was detected at the (Al50Ni40Ru10 alloy)/(modified CMSX-4) interface.