Fig. 5: Fracture and damage micromechanisms of AM CoCrNi, nTiC-CoCrNi and μTiC-CoCrNi samples deformed at 87 K. | Nature Communications

Fig. 5: Fracture and damage micromechanisms of AM CoCrNi, nTiC-CoCrNi and μTiC-CoCrNi samples deformed at 87 K.

From: In-situ nano-reprecipitation enables superior cryogenic mechanical properties in a 3D printable medium-entropy alloy

Fig. 5: Fracture and damage micromechanisms of AM CoCrNi, nTiC-CoCrNi and μTiC-CoCrNi samples deformed at 87 K.

a EBSD IPF plus IQ map of the fracture surface region of the AM CoCrNi sample, showing intergranular cracking. b The misorientation distribution across the two intergranular cracks marked in (a). c The fracture morphology of the AM CoCrNi, showing distinct intergranular facets. d EBSD IPF plus IQ map, SE and ECCI images of a magnified grain boundary region, showing the formation of micro-sized cracks or voids at the twin-grain boundary interactions. e The fracture morphology of the nTiC-CoCrNi sample, showing a ductile dimple-typed fracture behavior. f SE and g EBSD IPF plus IQ map probed closed to the fracture surface, showing the absence of intergranular cracking and the presence of high number-density microvoids. h BF-STEM and i HR-TEM images of the nTiC-CoCrNi sample cryogenically deformed to 18% strain, showing the blocking effect of TiC nanoprecipitate on the growth of deformation twins. j, k The fracture morphology of the μTiC-CoCrNi sample, showing a locally brittle fracture behavior of particle fracture and interface debonding. The inserted EDX Ti mapping in (j) marks the position of unmelted TiC particles. l The SE image and EBSD results taken close to the fracture surface of the μTiC-CoCrNi sample, validating the occurrence of interface debonding between the matrix and the micro-sized TiC particles as well as the particle cracking. Source data are provided as a Source Data file.

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