EFFECT OF HIGH-TEMPERATURE DEFORMATION ON THE PHYSICAL-MECHANICAL PROPERTIES OF IN SITU TITANIUM COMPOSITES WITH SILICIDE-BORIDE STRENGTHENING

Abstract

The efficiency of application of thermomechanical processing was investigated to optimize mechanical properties of cast ternary and multi-component hypoeutectic alloys on the basis of titanium with silicide-boride reinforcement, prepared by electron-beam crucible-skull melting. All the studied alloys exhibit low plasticity in as cast state. It was shown that high temperature deformation, namely, forging samples heated to 1050 °С in air, can significantly enhance properties of investigated alloys: the plasticity of ternary Ti–Si–B alloys by 4 to 6 times (from 0.5 to 2–3%), the fracture toughness by three times (from 11 to 36 MPa • m^0.5). For the alloys with Zr, Al and Sn additions the plasticity was increased by an order of magnitude (up to 0.2–0.3%) and the fracture toughness almost by twice. The highest high-temperature strength at sufficient fracture toughness 26 MPa•m^0.5 was obtained for the Ti₈₀Zr_1,2Al_5,5Sn_2,1Si_8,7B_2,5 alloy: 1038, 887 and 572 MPa at 600, 700 and 800 °С, respectively.