Lattice Mismatch
Lattice misfit is the difference in lattice structure between precipitates and the matrix phase. It affects mechanical properties and can lead to hardening.
Physical-Chemical Mechanism of Action
Lattice misfit arises from differences in crystal structure between precipitates (e.g., metals or carbon) and the surrounding matrix phase (e.g., steel). These differences create elastic strain fields that affect the mechanical properties of the material.
Metallurgical Relevance & Risks in Welding
High lattice misfit can lead to increased hardening and improved mechanical properties. However, it can also cause stress buildup and cracking, especially if precipitates are not well integrated into the matrix. This can affect cooling and mechanical load capacity of the weld.
Workshop Practice & Action Guidelines
To achieve optimal lattice misfit, pay attention to the choice of appropriate precipitates and matrix phase. Use suitable welding processes and parameters to ensure homogeneous cooling and good weld integrity. For high-misfit systems, post-weld treatments like normalizing or tempering can be helpful.