Chemical CompositionTable 1 outlines the chemical composition of the Ti-6Al-2Sn-4Zr-2Mo alloy. The primary elements include
Titanium (balance), Aluminum (5.50-6.50%), Tin (1.80-2.20%), Zirconium (3.60-4.40%), and Molybdenum (1.80-2.20%). Other elements such as Silicon, Iron, Oxygen, Nitrogen, Carbon, Hydrogen, and Yttrium are present in minimal amounts, with specific limits for each.
Mechanical Properties
Table 2 provides the mechanical properties of the alloy according to AMS 4976H-2012 standards. At room temperature, the tensile strength (σb) is ≥896 MPa, yield strength (σ0.2) is ≥827 MPa, elongation (A) is ≥10%, and reduction of area (Z) is ≥25%. At 482℃, these values are ≥621 MPa, ≥483 MPa, ≥15%, and ≥30% respectively. The alloy exhibits high creep resistance at 510℃ for 35 hours under 241 MPa with a deformation of ≤0.10%.
Application and Development
Ti-6Al-2Sn-4Zr-2Mo is a near α titanium alloy known for its high creep resistance, suitable for operating temperatures between 470℃ and 550℃. It is primarily used in the manufacture of discs and blades for high-pressure compressors in aero-engines. Developed in 1974, it has been extensively researched and is used in aircraft engines like F414, F119, and TRENT800.
Ultrasonic Testing
Table 3 describes the ultrasonic testing parameters as per AMS 2628. The classification includes near-surface hole depth, billet diameter, calibration FBH diameter, and acceptable amplitude levels. The signal-to-noise ratio is maintained at 2.5, with specific calibration and acceptable amplitude values depending on the billet diameter and depth.
Micrograph
Figure 1 presents a micrograph at 100X magnification, although specific details are not provided in the text.