Titanium Alpha Stabilization Factor

Titanium exists in two crystal forms: at room temperature it is hexagonal alpha titanium, at higher temperatures body-centered cubic beta titanium. Alloying elements like aluminum or oxygen stabilize the alpha phase and raise the transformation temperature. This is important for welding because the microstructure transformation during cooling can cause stresses and cracks. So you have to ensure that the part cools slowly and evenly, then the structure remains crack-free.