Welds are designed to meet a multitude of performance requirements including strength (tension/compression/torsion/bending), corrosion resistance, vibration, fatigue (mechanical/thermal), toughness, creep, electrical/thermal conductivity and appearance, to name a few. The functional results of any given weld are dependent on joint design, material selection and process selection, all of which affect each other.
Joint design is critical to weld product development and will depend heavily on braze and weld process selection and functional requirements. Laser welds for example require much greater attention to fit-up than say MIG welding. If distortion is an issue, it could be minimized by changing joint design, adding restraints or using heat sinks.
Material selection will be contingent on previously mentioned performance requirements, but designers must also take into account the heat-affected zone (HAZ) and fusion zone properties. Some materials may weld easily to itself, but when welded to a different alloy may have a propensity to crack unless careful precautions are taken. Post weld processing considerations must also be taken. Such considerations are non-destructive testing (NDT) or post-weld heat treatment (PWHT) to improve the properties of the weld region.
Process selection on the other hand, may take production rates and weld cycle time into consideration. If the weld is a repair, existing structures or equipment may dictate process because welding equipment such as a MIG guns may not be able to suitably access the weld joint. On the other hand, some materials are considered unweldable using conventional arc welding processes, but may be suitably joined using one of the many solid-state processes.
The number of scenarios that you may encounter during product development are infinite – make Advanced Welding Solutions your preferred partner.
Weld metal microstructures & toughness