Alternatives to Welding
Whenever Welding is difficult and expensive and if there is no essential need for the kind of metal continuity provided by welded joints. The main point is that welding processes in general are associated with elevated temperatures.
In many situations the application of heat may have adverse effects like crack formation, hardness and strength changes, production of brittle phases, microstructural modifications affecting corrosion resistance properties, unacceptable deformations, alignment and fit problems, introduction of residual stresses.
If the risks following the above effects entail the adoption of special procedures to counteract them, then welding becomes a much less attractive solution.
Among possible alternatives one could consider the following. Brazing and Soldering that require less heat and may provide adequate properties to the joint. Otherwise Mechanical Fastening, structural Adhesive Bonding, surface modification if effective, elimination of joint by design change.