LAUSR

Abstract Nanocrystalline metals are often strong but with a low thermal stability. In this study, a bulk nanocrystalline Mg-1.5at%Ti alloy with a high thermal stability is successfully fabricated by mechanical alloying and subsequent high-temperature/high-pressure consolidation. The rapid grain growth of nanocrystalline Mg and Mg-1.5at%Ti alloy starts at ∼100 °C (0.40 T m ) and 450 °C (0.78 T m ), respectively. The high thermal stability of nanocrystalline Mg-1.5at%Ti alloy can be attributed to the segregation of Ti atoms at grain boundaries. The high thermal stability of nanocrystalline Mg-Ti alloy enables us to consolidate the alloy powders at a high temperature of 400 °C (0.73 T m ) under a pressure of 4 GPa, yielding a bulk nanocrystalline Mg-Ti alloy with a high strength of 202 MPa and a large fracture strain of above 0.8.