Tensile Flow Behaviour and Fracture Studies of Beta Titanium Alloys at Elevated Temperatures

Tensile testing on metastable beta alloy with various microstructures was carried out in this study. Beta 21S is a metastable alloy that exhibits a wide range of material characteristics depending on the processing techniques used. Three different sheets that have been used in this paper which has the same substance but three different microstructures. At a strain rate of 0.001/s, the tensile test was done on a single sheet at five different temperatures. The sheet has developed varied microstructures, the tensile nature of the material varies the alloy’s characteristics. Mechanical characteristics for 400°C, 500°C, 600°C, and 7000°C are described for 21S sheets. The alpha phase sheet elongated at room temperature by 1-3 %, whereas the pure beta phase sheet elongated by 22-24 %. There is a significant improvement in the extension of the sheet with the variation in temperature for the alpha phase. The elongation of the pure beta phase does not alter as the temperature rises. The fracture surface was tested at all temperatures and the optimal temperature for forming the sheet has been determined

Hot Deformation Behavior of a Beta Metastable TMZF Alloy: Microstructural and Constitutive Phenomenological Analysis

A metastable beta TMZF alloy was tested by isothermal compression under different conditions of deformation temperature (923 to 1173 K), strain rate (0.172, 1.72, and 17.2 s−1), and a constant strain of 0.8. Stress–strain curves, constitutive constants calculations, and microstructural analysis were performed to understand the alloy’s hot working behavior in regards to the softening and hardening mechanisms operating during deformation. The primary softening mechanism was dynamic recovery, promoting dynamic recrystallization delay during deformation at higher temperatures and low strain rates. Mechanical twinning was an essential deformation mechanism of this alloy, being observed on a nanometric scale. Spinodal decomposition evidence was found to occur during hot deformation. Different models of phenomenological constitutive equations were tested to verify the effectiveness of flow stress prediction. The stress exponent n, derived from the strain-compensated Arrhenius-type constitutive model, presented values that point to the occurrence of internal stress at the beginning of the deformation, related to complex interactions of dislocations and dispersed phases.

CARTECH Ti 15V-3Cr-3Sn-3Al

CarTech Ti 15V-3Cr-3Sn-3Al (UNS R58153) is a metastable beta titanium alloy that offers substantial weight reduction in comparison with other engineering materials. If used in the solution heat treated condition, the alloy has excellent cold formability. In the aged condition, the alloy has high strength. It is acceptable for use up to 230 °C (550 °F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ti-180. Producer or source: Carpenter Technology Corporation.

Thermal Deformation Behavior of a New Metastable Beta Titanium Alloy

The thermal deformation behavior of a new metastable beta titanium alloy composed of Ti-Al-Mo-V-Nb-Cr was studied under different experimental conditions of varying temperatures (760°C~ 970°C) and strain rates (0.001s−1, 0.01s−1, 0.1s−1, 1s−1 and 10s−1) up to deformation amount of 60%. The hot compression experiments were completed on a Gleeble-3500 thermal analogue. The experimental results showed that the true stress of the Ti-Al-Mo-V-Nb-Cr titanium alloy decreased with increasing the temperature and decreasing the strain rate, the stress peaks and the steady-state stress values were higher with the decreasing of temperature at the same strain rate. The calculated values of the deformation activation energy were 187.87 kJ/mol in the two-phase region and 165.17kJ/mol in beta single-phase region. The corresponding constitutive equation was determined by the multiple linear regression calculation on the hot compression experimental data, on the base of Arrhenius equations.