Enhanced microstructural homogeneity in metal-matrix composites developed under high-pressure-double-torsion

• Composites of Cu–20 vol.% SiC are fabricated using high-pressure-double-torsion (HPDT).
• High homogeneity of microstructure in the composites is achieved.
• More homogeneous dispersion of the SiC particles is obtained using HPDT than HPT.
• Crystallographic texture in the composites is much weaker than in pure Cu.

In this work, metal-matrix composites of commercially pure copper (Cu) and silicon carbide (SiC) are synthesized by standard high-pressure torsion (HPT) and novel high-pressure-double-torsion (HPDT) processes of severe plastic deformation (SPD). Based on detailed microstructural examinations, it is found that significant homogeneity of fine particle distribution as well as weakness of crystallographic texture can be obtained in the composites fabricated using these processes. The most homogeneous particle distribution is obtained in the material processed under HPDT, which imposes the highest strain levels. Crystallographic texture in the composite is found to be weaker than in monolithic Cu processed under the same processing conditions. The randomization of texture in the composites is linked to the homogenization of the particle distribution.