A New Low-Cost β-Type High-Strength Titanium Alloy with Lower Alloying Percentage for Spring Applications

Spring applications require materials that possess a low Young’s modulus and high strength, in addition to having a lower alloying percentage for reduced costs. In this study, a new low-cost ¢-type titanium alloy with a lower alloying percentage than conventional ¢-type alloys was developed for spring applications using [Al]eq and [Mo]eq. The alloy is located in the near-¢ region and its ¢ transus temperature is about 1023K (750°C). This alloy could be cold rolled to a reduction ratio of 86.7% without any intermediate heat treatment. The solutionized alloy exhibits an ultimate strength of 925MPa, a 0.2% proof stress of 910MPa, an elongation of 18%, and a Young’s modulus of 78GPa; the comprehensive characteristics are better than those of conventionally used alloys (Ti-15-3 and ¢C) for spring applications.