The plastic flow behaviour of single crystals of the CoCrFeMnNi high-entropy alloy is shown to be greatly influenced by the twinning multiplicity on the stress-strain (σ(ε)) curves, the strain hardening coefficient Θ = dσ/dε, plasticity and fracture. It is shown that a maximum effect of strain hardening is obtained during the onset of twinning in two systems in the $\left[\overline{1}11\right]$- and $\left[\overline{1}44\right]$-oriented crystals, while a transition to the development of twinning predominantly in one system simultaneously with slip, is accompanied by a decrease in strain hardening. At 77K in the $\left[\overline{1}11\right]$-, $\left[\overline{1}23\right]$- and [011]-oriented crystals, when twinning develops in one system with slip, the extension of the linear hardening stage and plasticity increase as a result of the suppression cross-slip and shifting the neck formation according to the Considère condition to higher stress levels. The development of deformation by twinning only in several systems and the suppression of the relaxation of local stresses during twin-twin intersection by slip or twinning, leads to the failure of quasi-cleavage in the $\left[\overline{1}44\right]$-oriented crystals at 77K, after 50% strain. With the development of twinning predominantly in one system and a high density of dislocations, the $\left[\overline{1}11\right]$-, $\left[\overline{1}23\right]$- and [011]-oriented crystals show ductile failure, since the stresses for neck formation according to the Considère condition are reached before the stresses for brittle fracture.

孪生多重性对应力-应变（σ（ε））曲线，应变硬化系数Θ=dσ/dε，塑性和断裂的孪生多重性影响很大，表明CoCrFeMnNi高熵合金的单晶塑性流动行为。结果表明，在两个系统中孪生开始时，可​​以获得最大的应变硬化效果。$\left[\overline{\mathrm{1个}}11\right]$-和 $\left[\overline{\mathrm{1个}}44\right]$定向晶体，虽然主要在一个系统中过渡到孪晶的发展，但同时发生了滑移，但伴随着应变硬化的降低。在77K$\left[\overline{\mathrm{1个}}11\right]$-， $\left[\overline{\mathrm{1个}}23\right]$-和[011]取向的晶体，在具有滑移的一个系统中形成孪晶时，由于抑制交叉滑移和根据Considère条件将颈部形成转移到更高的应力，线性硬化阶段的延长和可塑性增加水平。仅在几个系统中通过孪生产生变形，并通过滑动或孪生抑制孪生-孪生相交过程中局部应力的松弛，导致了准解理作用的失败。$\left[\overline{\mathrm{1个}}44\right]$经过50％应变后在77K取向的晶体。随着孪晶在一个系统中的发展以及高位错的密度，$\left[\overline{\mathrm{1个}}11\right]$-， $\left[\overline{\mathrm{1个}}23\right]$-和[011]取向的晶体表现出延性破坏，因为在脆性断裂应力之前就已经达到了根据Considère条件形成颈部的应力。