Abstract
Improvement in shape recovery ratio in Ti-V-Fe-Al alloy at the temperature between 40℃ and 80℃ was attempted, and its application as a dental implant was discussed.In Ti-11.5V-1.7Fe-3.3Al alloy melted by an argon arc melting furnace with a low vacuum system, the shape recovery ratio at 80℃ was significantly improved from 44% to 85% by aging for only 3 seconds at 400℃ and succesive low temperature bending at -20℃.Furthermore, in the same alloy melted by an argon arc melting furnace with a high vacuum system, even better results with a higher recovery ratio and a low scatter value were obtained;that is, 98.5±0.8% at 80℃ and 89.9% even at 60℃ by the same treatment mentioned above.According to the oxygen analysis, approximate correlation between shape recovery ratio and oxygen concentration was observed, and reduction in oxygen concentration seems to be effective.The best condition to obtain the highest recovery at present is as follows:solution treat Ti-11.5V-1.7Fe-3.3Al with low oxygen concentration at 800℃ and age for 3 seconds at 400℃, then bend plastically at -20℃.According to the condition mentioned above, a model implant with 0.6mm thickness was prepared, and an opening angle with 50° in its edge part was memorized.After spape recovery treatment at 80℃, an opening angle with 40° was recovered.Based on these results, this alloy might have further room for improvement, but seems to be possible to use in dental implants.