Microstructure and mechanical properties of Nb15Al10Ti alloy produced by mechanical alloying and high temperature processing

摘要

In this work, an Nb15Al10Ti alloy produced by mechanical alloying was investigated. The milling of elemental powders of Nb, Al as well as TiAl intermetallic phase resulted in the formation of homogenous niobium solid solution, Nb_(ss), and refinement of powder particles. Powder after milling was consolidated by conventional hot pressing at 1300degC under pressure of 25 MPa as well as by hot isostatic pressing at 1200degC under pressure of 1 GPa. Microstructure of consolidated material was examined by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. Materials after consolidation were composed of three phases: niobium solid solution Nb_(ss), Nb_3Al intermetallic phase and titanium oxide dispersoid TiO. The analysis of the mechanical properties indicated that both refinement of microstructure as well as introduction of ductile Nb_(ss) into the microstructure contributed to very high yield strength and fracture toughness satisfactory for this strength.