Phase Boundary Mobility
Phase boundary mobility is the speed at which interfaces between different crystal phases move under the influence of a driving force. It affects the transformation rate in the weld pool.
Physical-Chemical Mechanism of Action
Interphase mobility describes how quickly boundaries between different crystal phases in a metal shift. This process is driven by forces such as temperature or stress.
Metallurgical Relevance & Welding Risks
Interphase mobility determines how quickly different crystal phases in the weld are transformed. Too high mobility can lead to rapid growth of metallization products, causing porosity or uneven deformation. Too low a value can result in incomplete transformation of the weld, leading to toughness loss and crack susceptibility.
Shop Practice & Action Items
To ensure optimal interphase mobility, it is important to precisely control the melting temperature and cooling rate. High temperature increases mobility, while slow cooling decreases it. For hard steels like martensite, rapid cooling is required to achieve a homogeneous structure. For softer alloys like austenite, keep the cooling rate controlled to avoid porosity.