Elevated-Temperature Mechanical Behavior of As-Cast and Wrought Ti-6Al-4V-1B

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 42; no. 10; pp. 3046 - 3061
• Main Authors: Chen, W., Boehlert, C. J., Howe, J. Y., Payzant, E. A.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2011; Springer
• Subjects: Alloy powders; ALLOYS; ANISOTROPY; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; DEFORMATION; Exact sciences and technology; EXTRUSION; Fatigue (materials); MATERIALS SCIENCE; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metallic Materials; Metals. Metallurgy; MICROSTRUCTURE; Nanotechnology; ORIENTATION; POWDER METALLURGY; PROCESSING; RATCHETING; STRESSES; Structural Materials; Surface layer; Surfaces and Interfaces; Symposium: Structural Materials for the Americas; TENSILE PROPERTIES; TEXTURE; Thin Films; Titanium; Titanium base alloys; Fatigue; Duplex Microstructure; Extrusion Axis; Induction Skull Melting; Ultimate Tensile Strength; Mechanical properties; Temperature; Aluminium alloy; High temperature; Vanadium alloy; Titanium base alloys
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-011-0618-y

This work studied the effect of processing on the elevated-temperature [728 K (455 °C)] fatigue deformation behavior of Ti-6Al-4V-1B for maximum applied stresses between 300 to 700 MPa ( R  = 0.1, 5 Hz). The alloy was evaluated in the as-cast form as well as in three wrought forms: cast-and-extruded, powder metallurgy (PM) rolled, and PM extruded. Processing caused significant differences in the microstructure, which in turn impacted the fatigue properties. The PM-extruded material exhibited a fine equiaxed α  +  β microstructure and the greatest fatigue resistance among all the studied materials. The β -phase field extrusion followed by cooling resulted in a strong α -phase texture in which the basal plane was predominately oriented perpendicular to the extrusion axis. The TiB whiskers were also aligned in the extrusion direction. The α -phase texture in the extrusions resulted in tensile-strength anisotropy. The tensile strength in the transverse orientation was lower than that in the longitudinal orientation, but the strength in the transverse orientation remained greater than that for the as-cast Ti-6Al-4V. The ratcheting behavior during fatigue is also discussed.