Twinning
Twinning is a symmetrical folding of a lattice region in face-centered cubic or hexagonal metals under high load. It leads to increased hardness and toughness, but can also cause cracks.
Physical-Chemical Mechanism of Action
Twinning occurs in face-centered cubic or hexagonal metals when they are loaded under high plastic strain. Lattice regions fold together symmetrically, leading to increased hardness and toughness.
Metallurgical Relevance & Welding Risks
Twinning can have positive effects by increasing strength. However, it can also lead to cracks if the material is overstressed or under uneven strain. This can happen especially near edges and corners.
Shop Practice & Action Guidelines
To use twinning effectively, weld metals under controlled plastic strain. Do not exceed the maximum strain to avoid cracking. For critical components, it is advisable to precisely regulate strain and cooling.