Fig. 3: Cryogenic tensile property of the additively manufactured alloys at 87 K.
a Engineering stress-strain curves of our nTiC-CoCrNi sample containing coherent TiC nanoprecipitates, in comparison to the reference AM CoCrNi sample and the μTiC-CoCrNi sample with micron-sized incoherent TiC precipitates. The long axes of the tensile specimens are perpendicular to the building direction, and the tensile properties of other orientations and fracture toughness are shown in Supplementary Fig. 9 and 10. The inset c displays the change in yield strength, ultimate tensile strength, and total elongation of the three samples when the temperature decreases from 298 K to 87 K. nTiC-CoCrNi sample displays a simultaneous improvement in strength and ductility at the cryogenic temperature, whereas the AM CoCrNi and μTiC-CoCrNi samples show a decreased ductility. The inset d shows the strain-hardening-rate curves of the AM CoCrNi and nTiC-CoCrNi samples at 87 K. b The product of cryogenic tensile strength and total elongation as a function of yield strength of the studied materials with the same orientation, in comparison to other AM alloys tested at near liquid-nitrogen temperature (77–87 K), including various medium/high entropy alloys8,9,55,56,57,58,59,60, Fe-based alloys61,62,63,64, Ni-based alloys65,66, and Ti-based alloy67. More details of the literature data are listed in Supplementary Table 1. The error bars represent standard deviation. Source data are provided as a Source Data file.
