Effect of Zone Melting Conditions on the Structure and Mechanical Properties of Casting Rods of a Near-Eutectic Co Alloy

Abstract—The structure and mechanical properties of casting rods of Co alloy 84KKhSR subjected to zone melting (ZM) under different conditions are studied using bending and compression tests. The optimum ZM conditions, namely, a melt zone temperature of 1150°C and a speed of melt zone movement through an inductor of 10 mm/min are determined based on three-point bending test data. These conditions are noted to ensure the maximum strength (\(\sigma _{{\text{u}}}^{{{\text{bend}}}}\) = 1970 MPa) and elastic deflection of sample; a fine eutectic structurally strengthened with longitudinally oriented dendrites forms in a rod. A high compression strength of 2300–2600 MPa and the hyperelasticity effect are shown to form at a melt temperature of 1150°C and a speed of melt zone movement of 1–20 mm/min. The elastic deformation is 2–3%, and the total reversible deformation can reach 6%; plastic deformation traces are absent. Prospects for the use of high strength hyperelastic cast near-eutectic rods are shown.