A high-entropy alloy with dislocation-precipitate skeleton for ultrastrength and ductility

Deformation mechanisms based on the multiscale molecular dynamics of a gradient TA1 titanium alloy

“…On one hand, active dislocation motion can effectively enhance the material's ductility. 56 It ensures that the material can endure more significant deformation without failure. On the other hand, the increase in dislocation density also enhances the material's strength.…”

New trends in additive manufacturing of high-entropy alloys and alloy design by machine learning: from single-phase to multiphase systems

“…AM processes, including PBF and DED, have shown many significant advantages in fabricating HEA components compared to traditional processing methods, such as casting, wrought and welding. Until now, many kinds of HEAs have been manufactured by AM methods, including single-phase HEAs (FCC or BCC) [20,[59][60][61][62][63][64][65][66][67] , EHEAs (FCC + BCC) [68][69][70][71][72][73][74] and precipitation-strengthened HEAs [75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] . Figure 3 summarizes the tensile yield strength against the uniform elongation of as-printed HEAs at room temperature.…”

“…In addition, for EHEAs manufactured by L-PBF, their tensile properties vary over a wide range, which may be caused by the relative proportions between the FCC and BCC phases and different microstructural features [68][69][70][71][72][73][74] . Another approach to strengthening the soft FCC matrix is to introduce second hardening phases, such as incoherent ceramic particles (carbides [75][76][77][78][79][80] , nitrides [81,82] , oxides [83] , and so on), and coherent L1 2 [84][85][86][87][88][89] . Among these second hardening phases, it was found that the coherent L1 2 phase can significantly improve the tensile strength of the as-printed FCC HEAs without seriously sacrificing ductility.…”

“…high-density dislocation networks and coherent particles to the matrix using the L-PBF technique and subsequent heat treatment. Similar methods have also been applied to other HEAs to improve their mechanical properties and corrosion properties, including Co 1.5 CrFeNi 1.5 Ti 0.5 Mo 0.1 , FeCoNiAl 7 Ti 7 and FeCoNiAl 3 Ti 3 [85][86][87][88] .…”

In Situ Atomic-Scale Quantitative Evidence of Plastic Activities Resulting in Reparable Deformation in Ultrasmall-Sized Ag Nanocrystals

“…How nanosized fcc metals (∼2 nm) accommodate plastic deformation and whether the generalized SF energy curve is a valid predictor of their deformation mechanism remain open questions. In addition, plastic deformation activity in pure metals, such as phase transitions, SFs resulting from partial dislocations, and deformation twinning, leads to permanent structural changes that are believed to be irreparable after unloading. ,,,,,− This phenomenon is supported by most of the reported molecular dynamics (MD) simulations and experimental studies on fcc metals, though a few MD simulations have predicted that the deformation twin can be repaired with unloading for nanosized fcc metals. − Furthermore, in most cases, the deformation of pure fcc metals is governed by the dislocation activity and deformation twins, and the phase transition from fcc to hexagonal close-packed (hcp) can only be observed under extremely high stress. − Whether such plastic deformation modes can occur under conventional deformation and whether the phase transformation in pure metals is reparable after the release of strain and stress remain unknown.…”