Mo-ZrC-Cu composites have been synthesized by reactive melt infiltration of Zr-Cu binary alloys into porous Mo2C preforms at 1300 degrees C for 10 min in argon. The influence of Zr content in the Zr-Cu infiltrator on microstructure and mechanical properties of Mo-ZrC-Cu composites are investigated. The assynthesized composites consist of three major phases of Mo, ZrC and Cu, after a complete reaction of Mo2C(s) + Zr-Cu(I) -> Mo(s) + ZrC(s) + Cu(I). Mo2Zr phase is formed when Zr content exceeds 50 at% in the Zr-Cu infiltrator. The formed ZrC grains have sizes less than 1 mu m with Mo solid solute inside. Meanwhile, nanoscale zones enriched in Cu and C are also detected in ZrC grains. The angular ZrC particles and rounded Mo grains become larger with increasing Zr content in the Zr-Cu infiltrator. With decreasing Cu content from 43.5 to 31 vol% in Mo-ZrC-Cu composites, the elastic modulus and flexure strength increase from 146 to 156 GPa and from 542 to 569 MPa, respectively. (C) 2018 Elsevier B.V. All rights reserved.