Cold-rolled Ti-Al-V-Zr-Fe titanium alloy tubing with outstanding tensile properties

• Published in: Journal of alloys and compounds 2023-01, Vol.931, p.167558, Article 167558
• Main Authors: Wang, Wenrui, Yuan, Lihong, Zhang, Hao, Wei, Zengliang, Zhang, Hui, Zhang, Wangfeng
• Format: Article
• Language: English
• Subjects: Aircraft hydraulic systems; Aluminum; Cold rolling; Deformation mechanisms; Hydraulic equipment; Hydraulics; Iron; Mechanical properties; Plastic deformation; Room temperature; Strengthening; Strengthening mechanisms; Tensile properties; Tensile stress; Textures; Ti alloy tubing; Titanium alloys; Titanium base alloys; Vanadium; X-ray Diffraction; Zirconium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167558

Increasing the operating pressure of the hydraulic lines is one of the directions to improve the comprehensive performance of the hydraulic system of an aircraft. However, the existing Ti-3Al-2.5V (limited strengths) and Ti-6Al-4V (poor cold formability) alloy tubing are not applicable to the hydraulic lines with an operating pressure over 28 MPa. In this work, a new type of Ti-Al-V-Zr-Fe titanium alloys were developed and the thin-walled seamless tubing was fabricated by cold rolling. After being annealed at 550 °C, Ti-4Al-2V-1.2Zr-0.3Fe (σb=1029 MPa, δ = 19%) and Ti-4.5Al-3V-1.5Zr-0.45Fe (σb=1102 MPa, δ = 18%) alloy tubing have outstanding room temperature tensile properties mainly due to dislocation strengthening. In addition, the strong radial textures in Ti-Al-V-Zr-Fe titanium alloy tubing, which increase the average Schmid factors under axial tensile loads, play a vital role in the strengthening contributions from dislocations and in the plastic deformation mechanisms. This work is of theoretical importance and practical value for developing aerospace hydraulic tubing with an excellent combination of mechanical properties. •The Ti-4Al-2 V-1.2Zr-0.3Fe tubing annealed at 550 °C: σb= 1029 MPa and δ = 19%.•The Ti-4.5Al-3 V-1.5Zr-0.45Fe tubing annealed at 550 °C: σb= 1102 MPa and δ = 18%.•The dislocation strengthening is the major strengthening mechanism of the tubing.•Strong textures are vital to the strengthening contributions from dislocations.•Strong textures are of significance to the plastic deformation mechanisms.