Sintering-temperature-dependent microstructure and properties of lamellar W-Cu composites

Dislocation density of W phase depended on both recovery process and pressure-sintering-induced thermal deformation. • Weak interfacial bonding caused by low sintering temperature promoted interlayer delamination under compression. • Lamellar W-Cu composites sintered at 850 °C exhibited the best strength-plasticity matching. The lamellar structure offers an effective strategy to improve the integrated mechanical and physical properties of W-Cu composites. However, as a key processing parameter for material fabrication, the underlying mechanisms by which sintering temperature regulates microstructural evolution and properties in lamellar W-Cu composites have remained unclear. In this study, the influences of sintering temperature on the microstructure and properties of lamellar W-30Cu composites and the related mechanisms were systematically explored. With rising sintering temperature, the grain size and dislocation density of Cu continuously increased, whereas the dislocation density of W first increased and then decreased. The electrical conductivity of composites increased progressively with elevating sintering temperature due to the increased densification and Cu grain growth. The compressive mechanical properties exhibited a complex temperature-dependent evolution. Lower sintering temperature (≤750 °C) caused weak interfacial bonding and poor plasticity. The composite sintered at 800 °C exhibited the highest yield strength owing to W dislocation strengthening, albeit with limited plasticity. Further heating to 850 °C slightly decreased yield strength but greatly improved plasticity, realizing superior strength-plasticity matching. This study provides fundamental understanding and technical support for processing optimization of high-performance lamellar W-Cu composites.