What is stress cracking or intergranular penetration in a brazing context and how is it avoided?
Nickel and nickel-based alloys are susceptible to cracking during brazing with silver brazing filler metals. This cracking is often known as inter-granular penetration or stress cracking. High nickel content copper alloys, such as 70:30 cupro-nickel, are also prone to this type of failure. Removing the source of stress will eliminate the problem. Silver-flo 60 is recommended where freedom from stress cannot be guaranteed. The relatively low zinc content and high brazing temperature make it less likely to initiate stress cracking.
