Semenenko V. The composite microstructures formation in high-melting carbide eutectics and their physical and mechanical properties

The dissertation is devoted to the investigation of formation regular perfect composite structures in eutectic systems on base Mo,Nb,Ta with carbide phases (20 : 46 vol. %) and model ones. Composites obtained by unidirectional solidification through creating of high statical (constant) temperature gradient on solid-liquid boundary. Given data on influence of structure formation parameters on process, which obtain regular composite. Specific feature of structural defects and phases formation and redistribution under various cooling conditions were studied. There аге found mechanisms of the matrix purification from carbon during heat treatment (up to 2g10-4 %) and of carbide phases coarsening . The improvement in plasticity and mechanical properties of heterophase systems is shown by attained. Composites with regular structures are stable up to 0,92 Tm. Also in given work shown utilization of unidirectional solydification for plastification of borid matrix and improvement in 3 : 9 times of wear