Dilution Micro-Crack
A tiny crack in the transition zone from unwanted mixing of filler and base metal, usually due to embrittlement.
Physicochemical mechanism of action
Mixing microcracks occur due to faulty mixing of filler and base materials in the weld metal. This undesirable mixing can lead to embrittlement, which in turn leads to microcracks.
Metallurgical relevance & risks in welding
These microcracks can lead to reduced toughness and increased crack initiation in the weld. They impair the mechanical properties of the material and can lead to premature failure under load.
Workshop practice & instructions
To avoid mixing microcracks, it is important to ensure careful selection of filler materials and correct mixing. Melting time and temperature should be precisely controlled to minimize embrittlement. For spray transfer welding, it is especially important that the gas flow is continuous and uniform.