Study on Creep-Fatigue Mechanical Behavior and Life Prediction of Ti2AlNb-Based Alloy

Abstract

Low-cycle fatigue, creep and creep-fatigue tests of Ti2AlNb-based alloy were carried out at 550 °C. Compared with low-cycle fatigue, a creep-fatigue hysteresis loop has larger area and smaller average stress. The introduction of creep damage will greatly reduce the cycle life, and change the fatigue crack initiation point and failure mechanism. Based on the linear damage accumulation rule, the fatigue damage and creep damage were described by the life fraction method and the time fraction method, respectively, and the creep-fatigue life of the Ti2AlNb-based alloy is predicted within an error band of ±2 times.

Plastic Shakedown Behavior and Deformation Mechanisms of Ti17 Alloy under Long Term Creep–Fatigue Loading

“…After unloading of stress, part of the residual strain is retained in the specimen, and the cyclic curve is not closed, and the plastic strain increment ∆ε p ≠ 0. Furthermore, the area enclosed by the stress-strain curve in cycle 1 is larger, which means the plastic strain energy ∆w p is greater [21]. Cycle 2 is shown in Figure 6b, the specimen still undergoes elastic deformation during the loading and unloading stages, but the total strain at the end of loading is smaller than that at the beginning of unloading in cycle 1.…”

Theoretical study of the effects of alloying elements on TiO2/Ti2AlNb interface adhesion properties

“…They show broad application prospects in the aviation field. Compared with traditional Ti alloys, they have higher aluminum contents 1,2 and can be used to achieve the effect of improving the thrust-to-weight ratio of aeroengines. 3 However, there are also some defects that hinder their practical application, among which the insufficient oxidation resistance is one of the most critical issues.…”

First-Principles Investigation on the Adsorption and Diffusion of Oxygen at the B2(110)–O(001) Interface in Ti2AlNb Alloys

“…Ti 2 AlNb alloys are regarded as the next generation of the most promising lightweight high-temperature aerospace structural materials due to their excellent mechanical properties, such as their good creep resistance, high strength-to-weight ratio, and satisfactory hot workability [1][2][3]. Ti 2 AlNb alloys are composed of an order of the orthorhombic (O) phase (space group: Cmcm, Pearson symbol: oS16), B2 phase (space group: Pm3m, Pearson symbol: cP2), and α 2 phase (space group: P6 3 /mmc, Pearson symbol: hP8) [4,5].…”