Journal
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Volume 804, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.msea.2020.140516
Keywords
CoCrNi; Medium-entropy alloy; HCP; TRIP; Strength; Ductility
Categories
Funding
- National Natural Science Foundation of China [51771184, 51801203]
- Open Project of State Key Laboratory of Environment Friendly Energy Materials [18KFHG02]
- Innovation Center of Nuclear Materials for National Defense Industry
Ask authors/readers for more resources
Introducing the transformation-induced plasticity (TRIP) effects into non-equiatomic CoCrNi medium entropy alloys (MEA) by increasing the content of Co to lower the stacking fault energy shows improved strength and ductility. The study found that the HCP phase was present in Co40 alloy, while the 2% HCP phase mainly precipitated at the interface in Co50 alloy. Tensile tests showed that Co40 alloy exhibited increased yield strength and ultimate tensile strength without sacrificing plasticity, while Co50 alloy showed significantly increased total elongation and UTS. Interrupted tensile tests revealed the microstructure evolution during deformation process in Co50 alloy.
Introducing the transformation-induced plasticity (TRIP) effects into the CoCrNi medium entropy alloy (MEA) to improve the strength and ductile of the alloy is a hot issue in MEA. Herein, we developed two novels non-equiatomic CoCrNi (with Co content of 40 and 50 at. %) MEAs with TRIP effects by increasing the content of Co to lowering the stacking fault energy. It was found that the HCP phase is too tiny to be neglected in Co40 alloy, while in Co50 alloy the 2% HCP phase mainly precipitating at the interface between the annealing twin and the matrix can be found. The tensile test results show that Co40 alloy exhibits a simultaneously improved yield strength (YS) and ultimate tensile strength (UTS) without sacrificing plasticity, while for Co50 alloy, the sample shows significantly increased total elongation (TE) and UTS. The microstructure evolution of Co50 alloy during the deformation process was systematically studied by interrupting the tensile test under different strains. This work proposed that non-equiatomic MEA with more desirable mechanical properties than the equiatomic one can be obtained via introducing TRIP effects.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available