Tailoring the strength-conductivity combination in Cu matrix composites via in-situ TiB2 synthesis
Yifan Yan, Yilin Qiu, Xi Zhang, Bao Wang, Rui Li, Haoran Wu, Wei Zheng, Weiyang Long, Guoshang Zhang, Zhiyuan Zhu, Pengfei Yue, Kexing Song
Abstract
Optimal interfacial bonding coupled with outstanding strengthening efficiency of reinforcement remains the cornerstone for developing high-performance Cu matrix composites. This study focuses on modulating both interface characteristics and microstructural architecture through in-situ processing, aiming to achieve a strength-conductivity balance in Cu matrix composites. Fabricated via direct current resistance sintering, the in situ TiB 2 /Cu composites exhibit increasing yield strength from 174 MPa to 388 MPa with increasing TiB 2 content, achieving a 155.9%-470.6% enhancement over pure Cu while maintaining room-temperature thermal conductivity exceeding 200 W/m·K. Notably, these in-situ composites achieve superior strength-conductivity synergy compared to both conventional Cu matrix composites and Cu alloys reported in existing literature. This is attributed to the in-situ process regulation achieving: semi-coherent interfacial bonding, grain refinement (98% refinement), dislocation strengthening (32.6-fold multiplication in dislocation density), and effective load transfer. Complementary mesomechanical simulations demonstrate that composite damage primarily originates from stress-strain concentration within the interparticle matrix regions, with matrix ductile fracture dominating the failure mode, and no significant interfacial debonding observed. These findings establish a theoretical framework for designing Cu matrix composites with exceptional strength-conductivity properties.