Abstracts Book - IMRC 2018

• SD3-O021 Invited Talk
LAYER STABILITY IN TI/AL COMPOSITES PRODUCED BY
ACCUMULATIVE ROLL BONDING (ARB) CONSIDERING THE
DEVELOPMENT OF LOCAL AND BULK TEXTURE
Oertel Carl Georg 1 , Scharnweber Juliane 1 , Romberg Jan 2 , Freudenberger Jens 2 , Skrotzki Werner 1
1 Technische Universität Dresden, Institut für Festkörper- und Materialphysik, Germany.
2 Leibniz-Institute for Solid State and Materials Research Dresden (IFW Dresden), Institute for
Metallic Materials, Germany.
Ti/Al laminated sheets have been produced by Accumulative Roll Bonding (ARB
[1]) at ambient temperature, both with and without intermediate annealing. A
maximum of eight and six ARB cycles was conducted, respectively.
Without annealing, pronounced shear banding across layers commonly
observed in ARB composites [e.g. 2] occurs after few ARB cycles, transforming
the layered structure in an Al-Matrix with embedded Ti-fragments. During
subsequent ARB processing, the thickness reduction of the latter becomes very
inhomogeneous, being overall significantly retarded compared to the
geometrical reduction of the sheets. An annealing in between rolling cycles was
found to promote homogeneous deformation of both phases during ARB,
resulting in Ti/Al-composites with stable layers with a minimal spacing of about
4 µm after eight ARB cycles [3].
The evolution of microstructure and local texture of both Al and Ti was studied
by electron backscatter diffraction, the bulk texture was measured by neutron
diffraction.
It was found that during intermediate annealing, recrystallization occurs in both
Al and Ti, retarding the microstructural refinement. The bulk texture of Al is
dominated by S, copper and brass component. With intermediate annealing,
each rolling and annealing step strengthens and weakens the rolling
components, respectively. In Ti, the usual 30° tilt of the c-axis around the rolling
and towards the normal direction was observed with maxima at either or being
parallel to the rolling direction. During the intermediate annealing, the latter
component becomes dominant.