Scientific and technical background for application of niobium as adhesion-active component of metal brazes for oxide and nitride materials brazing

Abstract

An activation of metal solders with niobium was considered for the brazing of the refractory (Al₂O₃-SiO₂)oxides and (AlN-TiN), Si₃N₄ nitrides. Capillary and contact processeses were investigated on a boundary between the specified nonmetals and the Ni-51,9Nb and Cu-6Ni-51,9Nb% (wt.) melts. It was established, that niobium influences positively on the adhesive properties of the melts; presence of silicon in a composition of the oxide and nitride materials promotes the wettability. Brazed joints were obtained for the nonmetals under investigation with themselves and with refractory metals (Nb, Mo). Bend strength of the brazed joints was 75-90% of the bend strength of the corresponding monolithic ceramic materials. That exceeds by 1,5-2 times the bend strength of the similar joints obtained elsewhere by diffusion welding. Obtained brazed joints are characterized by the higher working temperatures in comparison to similar joints obtained with the standard titanium-containing brazes.