The 1.5 mm thick Cu/Al composite sheet was obtained after explosive-welding and 6 passes cold rolling. The effects of annealing temperature and time on the microstructure, mechanical properties, and conductivity of cold-rolled Cu/Al composite sheets were investigated. The results show that the thickness of the interface diffusion layer with compounds of Al₂Cu, AlCu, and Al₄Cu₉ increases with the increase in annealing temperature and holding time, and the total activation energy is 108 kJ mol⁻¹. The tensile strength of composite sheets decreases and the fracture elongation increases with the increase of annealing temperature. Especially when the annealing temperature increased from 300 ℃ to 350 ℃, the tensile yield strength decreased from 225 MPa to 77 MPa, and the elongation increased from 16% to 37.5%. The tensile-shear strength of composite sheets reaches to 117 MPa after annealing at 400 ℃ for 2 h. The conductivity of composite sheet is greatly affected by the annealing time. At the annealing temperature of 350 ℃ and time of 4 h, the composite sheets show a better conductivity of 96.4% IACS.

The effect of rolling temperatures on the interface microstructure and mechanical properties is investigated using 2-mm-thick TA1/Q235B composite sheets, which were prepared after nine passes of hot rolling of explosive welded plates. The results show that the vortex region and the transition layer exist in the interface at the explosive welded plate, while only the transition layer exists in the interface after hot rolling. The transition layer is composed of α-Ti, TiC, Fe, and FeTi, and the thickness increases with the increasing rolling temperature. The microhardness of the explosive welded plate is higher than that of the hot-rolling sheet, and the microhardness of interface are higher than that of matrix metals. The interface shear strength and tensile elongation of the hot-rolled sheet increase with the increasing hot rolling temperature, while the ultimate tensile strength (UTS), yield strength (YS) and Young modulus decrease with the increase of hot rolling temperature. The shear strength of sheets is related to the interfacial compounds, and the tensile strength is mainly affected by the grain morphology of the matrix.

The effects of solution treatment time on the morphology evolution of Si particles and the thermal conductivity and tensile properties of Sb-modified alloys were studied. The results show that the evolution of Si particles follows four mechanisms: spheroidization, necking and splitting of particles with large aspect ratios, fusion of spherical particles, and coarsening controlled by diffusion. The first three mechanisms mainly occur at the early stage of solution treatment. The addition of Sb does not change the evolution law of the Si particles, but it does change the contribution of various evolution mechanisms, including promoting spheroidization, fusion, and coalescence, as well as significantly reducing the coarsening rate, which makes the thermal modification of Sb-modified alloys more effective. The increase in thermal conductivity during solution treatment is related to the decrease of the anharmonicity of lattice vibration, lattice wave scattering, and electron scattering of Si particles. The 0.4 wt. % Sb-modified alloy exhibits excellent tensile strength and elongation under as-cast T4- and T6-heat-treated conditions, because the modification significantly reduces the stress concentration of the Si particles and delays the germination and propagation of microcracks.