Superplastic forming and accuracy of denture base made of Ti-6Al-4V alloy

Superplastic forming for Ti-6Al-4V denture base was studied and the fabrication accuracy was also investigated. The ceramic die used to fabricate the denture base was made by mixing the green of ZrO₂ and TiO₂ with PVA and press them into oral cavity model to get the semi-finished ceramic die. Then it was sintered at 1300°C for 3 hours in the atmosphere to produce the finished ceramic die with the complicated oral shape and enough strength for superplastic forming. The 0.8 mm Ti-6Al-4V sheet was blow formed to be denture base at 925°C. The average thickness of denture base framework has 21% reduction compared with the original sheet by superplastic forming. The accuracy of Ti-6Al-4V denture base framework was also investigated using the impression measuring method. Difference between the denture base and the ceramic die almost does not affect the accuracy and the thickness distribution of denture base also satisfies ordinary clinical requirements.