Microstructure and properties of Cu-Ti matrix composites with in situ dispersive oxide fabricated by internal oxidation process

Cu-Ti alloy, as a typical aging strengthening alloy, possesses the high strength and wear resistance, widely used in engineering applications. However, the conductivity of Cu-Ti alloy significantly decreases when the content of Ti exceeds 4 wt%, which is due to the scattering effect of lattice distortion of the matrix on electrons caused by the difference in atomic radius between Cu and Ti. The precipitation of in situ dispersive nano-Cu-Ti-O compounds particles and heat treatment is expected to reduce lattice distortion of matrix and improve the strength of materials. We employed Cu2O as the oxygen source to generate oxide particles to reinforce Cu-Ti composites through an internal oxidation process. The influence of solid solution time on the microstructure and properties of nano-oxide- reinforced Cu-Ti composites is explored, and the composition of oxide particles is Cu2Ti4O with a size of approximately 100 nm, which has a good interface bond with matrix. The strength reaches 675 MPa when the solid solution time is 16 h, and the strengthening mechanism and conductivity improvement mechanism were discussed. Actually, Ti atoms precipitated as beta '-Cu4Ti and Cu2Ti4O, reducing lattice distortion of the matrix and increasing electrical conductivity after solid solution and aging treatment. This study provides a novel approach for preparing nano-oxide-reinforced Cu-Ti matrix composites.