Study on spinning feasibility of Ti75 cast alloys

Power spinning feasibility of the Ti75 (Ti-3Al-2Mo-2Zr) alloy tube cast by a skull furnace ZHN-100 was studied; effects of parameters such as the spinning temperature (T), spin wheel feed rate (f) and pass thinning rate (Ψ_tn) on the spinning process performance of the alloy tube were discussed and the changes of cast microstructure and properties under different thinning rates were also researched. The results show that the appropriate first-pass spinning temperature is 600-800°C for the cast Ti75 alloy tube when the multi-pass heating backward spinning was applied; while the spinning temperature of the follow-up passes should be lowered gradually in order to ensure the product performance and accuracy. The spin wheel feed rate of 0.42-0.67 mm/r is proper, for which the higher value can ensure the easy-to-punch, and the smaller one is in favor of the surface quality increase of the product. The first-pass thinning rate should not be more than 30%, in order to ensure the smooth progress of spinning. The maximum thinning rate Ψ_t of wall thickness for the cast Ti75 alloy tube is up to 80%, confirming its excellent spinning properties.