Precipitation-Induced Lattice Distortion
Precipitation-induced lattice distortion occurs due to unequal atomic radii in newly formed phases, which hinders dislocation movement and reduces strength.
Physical-Chemical Mechanism of Action
During the precipitation of metals or alloys, new crystal phases can form. These phases often have different atomic radii, leading to local mechanical expansion or compression of the crystal lattice. These distortions impair the free movement of atoms within the lattice.
Metallurgical Relevance & Welding Risks
Precipitation-induced lattice distortion can lead to a reduction in strength and toughness of the material. It increases susceptibility to cracking and wear, especially under mechanical stress. In heavy welding processes like TIG or MIG, this distortion can be amplified by uneven heat transfer.
Workshop Practice & Action Instructions
To minimize precipitation-induced lattice distortion, it is important to ensure uniform heating and cooling of the weld. Use high-quality shielding gases and appropriate welding parameters for heavy metals like steel or nickel. If necessary, special lattice distortion reducing agents can be added to the weld pool to stabilize the crystal structure.