STP432

    Relation of Strength and Toughness to Fine Structures in a Beta Titanium Alloy

    Published: Jan 1968


      Format Pages Price  
    PDF Version (1.6M) 24 $25   ADD TO CART
    Complete Source PDF (8.3M) 24 $92   ADD TO CART


    Abstract

    Although a great deal of mechanical properties data on titanium alloys have appeared in the literature, no attempt has been made to relate the fine structures in beta titanium alloys to strength and fracture toughness. Therefore, strength and fracture toughness properties of B-120VCA—obtained through a variety of thermal and thermomechanical treatments—were related to fine structures by transmission electron microscopy, electron fractography, etc. Effects of (1) prior solution-treating temperatures, (2) cold working after solution treating, and (3) cold working both before and after solution treating were evaluated in terms of strength and fracture toughness, and parallel fine structure studies. The double cold-work treatment, without aging, produced σt with a fracture toughness of 115 ksi√in. and may be promising for certain high-strength applications. Also short aging times produce unique combinations of strength and fracture toughness (σt ≈ 190 ksi, Kc ≈ 70 ksi√in. The kinetics of β→ α transformation were characterized and related to fracture toughness and strength properties. Precipitation of omega was suggested in the solution-annealed material during cooling to room temperature; further growth of this phase upon prolonged aging at 600 F was established. At 900 F, omega growth was limited, being replaced by alpha precipitation first in a discontinuous and later in a general dispersion.

    Keywords:

    titanium alloys, mechanical properties, fracture toughness, dynamic structural analysis, electron microscopy, electron fractography, aging, mechanical treatments, transformation


    Author Information:

    Banerjee, BR
    Associate director of research, Hunter Research Laboratories, Crucible Steel Co., Pittsburgh, Pa.

    Hauser, JJ
    Staff scientists, Hunter Research Laboratories, Crucible Steel Co., Pittsburgh, Pa.

    Capenos, JM
    Staff scientists, Hunter Research Laboratories, Crucible Steel Co., Pittsburgh, Pa.


    Paper ID: STP33621S

    Committee/Subcommittee: B10.01

    DOI: 10.1520/STP33621S


    CrossRef ASTM International is a member of CrossRef.