A new method to strengthen turbine disc superalloys at service temperatures

TMW® superalloys have superior mechanical properties up to 725 °C. Numerous annealing twins are present because these alloys have relatively low stacking fault energies. Nanoscale deformation twins are the dominant mechanism during creep and tensile testing at 725 °C. In addition to traditional strengthening mechanisms enhanced by higher Ti addition, twinning structures enhanced by higher Co addition also play an important role in strengthening coarse-grained alloys at high temperatures. The effects of twin strengthening are discussed.