A novel coating method to fabricate ZrC reinforced metal matrix composite cladding

Abstract As a novel method to fabricate ZrC-reinforced Zr-based composites, pre-melted electron beam freeform fabrication was proposed to elevate the hardness and wear resistance of Zr alloys. After careful choice for material and precise shape design, a graphite diversion nozzle, which was used as a preliminary vessel for diffusion of C from graphite into liquid Zr under the oscillating effect of bombardment and stir by electron beam, played a predominately critical role in ZrC formation and the consequent ZrC/Zr composite fabrication, indicating a pre-melted process during electron beam freeform fabrication. The crystal structure of ZrC was characterized by ordered arrangement along 〈111〉, and the interface between ZrC and Zr matrix was negative lattice misfits. The strain at the interface led to a deflection angle of about 4° between the (200)ZrC and (101)Zr. The lattice distortion at the interface and dispersion strengthening effect of ZrC were the main reasons for the increase in hardness and wear resistance of Zr matrix composites.