LAUSR

Abstract In this work, nickel aluminum bronze (NAB) alloys with superior mechanical properties were prepared by continuous heavy hot rolling at two different temperatures. When rolled at 950 °C with a reduction ratio of 90%, slabs with an ultrahigh strength over 1300 MPa and an elongation nearly 5% can be obtained, and the strength can be further improved by subsequent ageing process. The contribution of each strengthening factor to the yield stress was analysed using a semiquantitative model. The results show that grain refinement and dislocation strengthening are the two most important factors. Besides, a subsequent 700 °C/5min heat treatment was carried out to improve the ductility of rolled slabs to nearly 15%, while the yield strength can be maintained at around 800 MPa. After heat treatment at 700 °C, high density annealling twins were generated. It was revealed that the intracrystalline twin boundaries helped to refine the microstructures and such refinement benefited the strength and ductility in many ways.