COLLABORATIVE RESEARCH AND DEVELOPMENT (CR&D) Delivery Order 0043: Deformation and Texture Development During Hot Working of Titanium

摘要

This research in support of the Air Force Research Laboratory Materials and Manufacturing Directorate was conducted at Wright-Patterson AFB, Ohio from 3 November 2005 through 31 January 2008. This task developed constitutive models for alpha/beta titanium alloys with colony-alpha microstructure and validated texture prediction models for plate rolling. A method for separating the textures of primary alpha alpha(sub p) and secondary alpha alpha(sub s) in alpha/beta titanium alloys with a duplex microstructure was developed. Utilizing electron backscatter diffraction (EBSD) and energy- dispersive spectroscopy (EDS), the approach relies on the non-uniform partitioning of alloying elements between primary alpha and regions containing secondary-alpha lamellae and residual beta matrix phase. The method was evaluated using samples of Ti-6Al-4V for which vanadium partitions strongly to secondary alpha + beta regions. The technique thus provides a useful tool for quantifying the evolution of deformation texture in the primary alpha and transformation texture in secondary alpha formed via decomposition of the beta matrix following hot working or final heat treatment.