Microstructures and textures of a Cu–Ni–Si alloy processed by high-pressure torsion

• HPT for 10 turns led to an equiaxed grain size of ∼200 nm in Cu–Ni–Si alloy.
• The fraction of high-angle boundaries is ∼68% in the alloy after HPT for 5 turns.
• The texture after HPT is characterized by typical shear components of f.c.c. metals.

Experiments were conducted to evaluate the evolution of microstructure and texture in a commercial Cu–2.5%Ni–0.6%Si (wt.%) alloy during processing by high-pressure torsion (HPT) at room temperature up to a maximum of 10 turns. It is shown that HPT leads to grain refinement to a mean equiaxed grain size of ∼200 nm, the evolution occurs rapidly at the edges of the disks but progresses more slowly in the center of each disk and ultimately, after 10 turns, the grain structure is reasonably homogeneous. There is an evolution also in the grain boundary misorientations and after 5 or more revolutions the fraction of high-angle grain boundaries is about 68%. The texture after HPT is characterized by typical shear components of face-centered cubic metals and mainly by the reinforcement of the {1 1 1}〈2 1¯1¯〉 orientation of the A* texture component.