Grain refinement during high temperature tensile testing of prior cold worked and peak aged Cu–Ti alloys: Evidence of superplasticity

摘要: Abstract The high temperature tensile properties of solution treated, cold worked and peak aged Cu–1.5 wt.%Ti Cu–4.5 wt.%Ti alloys have been investigated in the range from room (RT) to 550 °C. Yield strength (YS) (TS) Cu–1.5Ti alloy were found be independent test up 350 °C decreased thereafter, In case Cu–4.5Ti alloy, behaviour similar was observed. decrease strengths beyond is attributed coarsening β′ precipitate particles at 450 °C precipitation equilibrium phase β TEM analysis confirms presence metastable coherent Cu 4 Ti when tested 3 Ti, It interesting note that Cu–Ti elevated temperatures, ductility (% elongation) increase with 550 °C which dynamic recrystallisation. large elongation (160%) observed an indication superplasticity. We are reporting discovery superplasticity for first time. Ductile mode fracture these i.e. 350 450 °C. High superior those Cu–Be (C17200 C17510).