Controlling the tensile properties of a high-strength-ductility Ti2AlNb alloy by hot rolling

Abstract

In this work, a high-strength-ductility Ti2AlNb alloy is fabricated by hot rolling the compact prepared by spark plasma sintering. The microstructure and tensile properties of the rolled sheets were controlled by changing the thickness reduction and rolling pass. Results show that rolling causes grain growth, larger thickness reduction results in pronounced grain coarseness. Rolling cannot cause recrystallization but reheating can. Higher thickness reduction results into higher recrystallization ratio, which decreases with increasing the reheating times. All sheets have tensile strengths higher than 980 MPa with elongation higher than 9%. The multiple rolling process causes the increase in ultimate tensile strength (UTS) and yield strength but decrease in elongation (EL). The maximum UTS of 1048.1 MPa is obtained after two rolling passes with 42% thickness reduction per pass. The maximum EL of 12.6% is obtained after reheating the single pass rolled sheet with 30% thickness reduction. All the sheets present ductile fracture mode.

Keywords

• Hot rolling
• Spark plasma sintering
• Ti2AlNb alloy
• Strength
• Ductility