| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1578510 | Materials Science and Engineering: A | 2011 | 11 Pages |
The evolution of microstructure during local rapid (induction) heat treatment (LRHT) and its effect on the tension and fatigue properties of Ti–6Al–4V with an initial microstructure of fine-grain equiaxed alpha or coarse-grain colony alpha were investigated. LRHT of material with an initial equiaxed condition formed a graded microstructure that varied from a fully transformed one at the surface to a bimodal (equiaxed/transformed) one at the center. After final aging (LRHTA), such a material was characterized by an attractive blend of tension and fatigue properties (UTS = 1285 MPa, elongation = 6.3%, endurance limit 710 MPa). An analysis of the dependence of mechanical properties on the volume fraction of heat-treated material revealed that LRHTA processing to 50% transformed in the critical cross section (from point of view of maximum applied loading) gave a balance of tensile properties similar to those obtained via bulk (100%) rapid heat treatment of Ti–6Al–4V. In contrast, the LRHTA of Ti–6Al–4V with a coarse-grain colony-alpha preform condition required longer heating times to refine the structure and provided only a modest improvement in mechanical properties.
Research highlights▶ A detailed study of the influence of LRHT on the microstructure and properties of Ti–6Al–4V was performed. ▶ LRHT of Ti–6Al–4V yields a microstructure consisting of a radial gradient in beta-grain size. ▶ Such a microstructure is a result of the temperature gradient developed during rapid heating. ▶ LRHTA of Ti–6Al–4V produces an attractive balance of tensile and fatigue properties. ▶ LRHT properties are noticeably better than those obtained with conventional treatments.
