Abstract
The inverse gradient-grained CoCrFeMnNi high-entropy alloy with a desirable mechanical property that evades the strength-ductility trade-off is fabricated by the process of cold rolling and subsequent laser surface heat-treatment.Due to the gradually decayed thermal effect along with the thickness,the grain size increases from the hard core to the soft surface in terms of the inverse gradient-grained sample,which is in good consistent with the microhardness profiles.The hetero-deformation induced strengthen-ing and strain hardening caused by the inverse gradient-grained structure improve the strength-ductility combination,as well as the high-order hierarchal nanotwins due to the enhanced interaction with dis-locations.For the laser surface heat-treatment technique,the strength and ductility are significantly in-creased by enlarging the microhardness difference and decreasing the thermal stress.Considering the high volume fraction of gradient-grained layer and a great deal of high-order hierarchal nanotwins in the central region,the laser surface heat-treatment technique is a promising way to produce the gradient-structured materials without thickness limitation.
基金项目
Zhejiang Provin-cial Natural Science Funds of China(LZ20E050003)
Wenzhou Science and Technology Projects(ZG2020038)
Wenzhou Science and Technology Projects(H2020004)
NETL
NSTL
维普
万方数据