Secondary Phase Precipitation Kinetics
Secondary phase precipitation kinetics describes how new phases form and spread in supersaturated solid solutions. This process is controlled by diffusion temperature and concentration gradients.
Physico-chemical mechanism of action
Secondary phase precipitation kinetics refers to the formation of new phases in a supersaturated crystal lattice. This happens through diffusion of atoms or ions from the supersaturated phase into a new, stable phase. The rate of this precipitation depends on diffusion temperature and concentration gradients.
Metallurgical relevance & risks in welding
In welding fabrication, secondary phase precipitation kinetics can lead to phase differences that affect the microstructure. Too fast precipitation can lead to crack-prone structures like martensite, while too slow precipitation results in coarsened grain and low toughness.
Workshop practice & instructions
To control secondary phase precipitation kinetics in welding, it's important to optimize diffusion temperature and cooling rate. Too fast cooling can be achieved by using liquid coolants or by reducing weld thickness. Slow cooling can be achieved by using a heat exchanger or by using stable welding materials.