Active Brazing Alloy Produced by Electroless Plating Technique

Abstract

It is known that ceramics in general, are either non-wetting or show poor wetting by pure metals. However, good wetting behaviour is one of the most important requirements for successful brazing. This paper will introduce an electroless coating technique used to produce an active brazing alloy (ABA). The technique can also be extended to produce other binary and ternary ABAs. Cu-25Ti was produced by precipitation of Cu on Ti powder after 19 cycles. The initial plating shows that for 60 minutes of deposition, around 9wt% of copper can be deposited on 15 grams of titanium powder. The wetting behaviour of this ABA on α-Si 3 N 4 substrate shows a rapid decrease of the contact angle and that equilibrium is reached after 15 minutes with an angle ≃ 20°. SEM and XRD characterisation are presented as well as the microstructure of an ABA-Si 3 N 4 interface.