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

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 degrees 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.