1500 MPa级新型超高强中韧钛合金

A New Type Extra-High Strength and Medium Toughness Titanium Alloy of Ti-1500

针对目前高强韧钛合金发展的瓶颈,从分类应用角度考虑,在现有高强韧钛合金的基础上,通过Mo当量选择合金元素的种类和权重,结合组织结构设计,设计了一种新型超高强中韧亚稳β钛合金。经过实验室和中试规格铸锭的加工和测试,在优化的锻造和热处理工艺下,该合金可以稳定达到两种强度级别,一种是抗拉强度大于1500 MPa、延伸率大于5%、断裂韧性大于45 MPa·m^(1/2);另一种是抗拉强度大于1300 MPa、延伸率大于6%、断裂韧性大于60 MPa·m^(1/2)。相比于现有高强韧钛合金,这两种强度级别钛合金均显示出明显的性能优势。

Aiming at the development bottleneck of high strength and high toughness titanium alloy,from the perspective of classification applications,and based on existing research of extra-high strength and high toughness titanium alloy,a new type of metastableβ-titanium alloy was designed by selecting the types and weights of alloying elements by Mo equivalent,combined with the design of the structure.After processing and testing of ingots of laboratory and pilot scale specifications,under optimized forging and heat treatment processes,the alloy can stably reach two strength levels.One is that the strength is greater than 1500 MPa,the elongation is greater than 5%,and the fracture toughness is greater than 45 MPa·m^(1/2);the other is that the strength is greater than 1300 MPa,the elongation is greater than 6%,and the fracture toughness is greater than 60 MPa·m^(1/2).In comparison with the existing high strength and high toughness titanium alloys,there is evident superiority of the new alloy for any performance levels.