A lightweight orthorhombic-phase strengthened TiZrVNbAl multicomponent intermetallic alloy with promising ambient ductility and high-temperature strength

High-temperature alloy with good ambient ductility, high elevated-temperature strength and low density is desired for industrial application. Here, a novel lightweight TiZrVNbAl multicomponent intermetallic alloy with good combination of ambient ductility and high-temperature strength was developed. The designed alloy is composed of multicomponent B2 intermetallic matrix and dispersed micro-scale orthorhombic-phase (O-phase) precipitates. The multicomponent B2 intermetallic matrix can undergo plastic deformation through the mixture of planar and wavy slip of b = a<111> and b = a<001> dislocations, while the O-phase deforms by producing dislocation and stacking faults. Moreover, the O-phase can effectively contribute to strength by impeding dislocation motion at elevated temperatures (600 °C–800 °C). Consequently, the TiZrVNbAl alloy exhibits a large elongation of ∼14%, high specific tensile yield strength of ∼171.2 MPa g/cm³ at room temperature and a high specific compressive strength of ∼62.3 MPa g/cm³ at 800 °C. The present results will give new insights into the development of lightweight ductile high-temperature alloys.