Friction welding buffer layer
Friction weld buttering is a technique where a special intermediate layer is applied to avoid brittle intermetallic phases and increase joint strength. This buttering layer protects the core material from direct contact with the friction tool.
Physical-Chemical Working Mechanism
Friction welding can form brittle intermetallic phases that soften the material and promote cracking. The buffer layer creates a barrier between the core material and the friction medium, preventing direct contact and avoiding these brittle phases.
Metallurgical Relevance & Welding Risks
Without buffering, brittle intermetallic phases can form, significantly reducing weld strength and promoting cracks. This can lead to early component failure. The buffer layer protects the core material and increases its toughness.
Shop Practice & Action Instructions
For friction welding of hard-to-weld material combinations, a buffer layer is essential. The layer should be made of a metallurgically compatible material that works well with the metals involved and prevents brittle phases. Buffer thickness is typically 0.1 to 0.3 mm. Apply it before welding by spraying or painting.