Abstract:The effect of intermetallic compound (IMC) thickness on the thermal and mechanical properties of Al/Cu honeycomb rods was investigated. The Al/Cu honeycomb rods were fabricated using repeated hydrostatic extrusions at 200 °C. During the process, an IMC layer with 1 mm in thickness was generated at the Al/Cu interface. Different IMC thicknesses were obtained by post-heat treatment at 420 °C for 0.5 to 2 h. The IMC thickness increased to 10.1 mm. The IMC layers were identified as Al₂Cu (θ), AlCu (η₂), and Al₄Cu₉ (γ₁) phases. The thermal conductivities in the longitudinal direction and cross direction decreased by 11.9% ((268±4.8) to (236±4.4) W/(m·K)) and 10.4% ((210±3.2) to (188±2.8) W/(m·K)), respectively, with increasing IMC thickness. The ultimate tensile strength and elongation of the Al/Cu honeycomb rod are (103±8.4) MPa and (73±6.2)%, respectively. The ultimate tensile strength increased to (131±6.5) MPa until the IMC thickness reached 7.7 mm. It subsequently decreased to (124±3.9) MPa until the IMC thickness reached 10.1 mm. The elongation of the Al/Cu honeycomb rod then sharply decreased to (29±2.5)% with increasing IMC thickness.

Key words: intermetallic compound; Al/Cu honeycomb rod; anisotropy; thermal conductivity; tensile strength; hydrostatic extrusion