Journal of Materials Science, Vol.34, No.7, 1447-1460, 1999
A comparison of strengthening mechanisms in rolled and axisymmetrically deformed Ti-20Y composites
Two Ti-20%Y metal-metal composites were deformation processed: one axisymmetrically and the other by rolling. The microstructures, preferred crystallographic orientations, and tensile strengths of each were measured periodically as the deformation progressed. The axisymmetrically deformed Ti matrix developed a [10 (1) over bar 0] fiber texture, and the rolled composite acquired a texture with the [0001] tilted 31 degrees from the sheet normal toward the transverse direction with [10 (1) over bar 0] parallel to the rolling direction. The orientations of the {10 (1) over bar 10}[11 (2) over bar 0] and [0002][11 (2) over bar 0] slip systems in Ti with these textures were used in conjunction with the maximum possible slip distances for dislocation travel in each specimen to demonstrate that the axisymmetrically deformed material should be stronger than the rolled material for composites of equal phase thickness and spacing. The strengths of the two composites measured in this study were compared at similar microstructural phase sizes and spacings, and the axisymmetrically deformed composite was indeed found to be somewhat stronger, although the difference in strengths was not large.