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在塑性分切应变幅(γ_(pl))约为10~(-4)～10~(-2)范围内,研究了共面双滑移取向[233]和单滑移取向[4 18 41](Shimid因子Ω=0.5)铜单晶体的循环形变行为。当γ_(pl)<2×10~(-3),[233]晶体的初始硬化速率θ_(0.2)较低,几乎与应变幅大小无关。当γ_(pl)>×10~(-3),θ_(0.2)随γ_(pl)的增加而显著增大。当γ_(pl)≥3.5×10~(-3)时,[233]晶体的循环硬化曲线出现二次硬化阶段,且二次硬化的临界应变幅介于单滑移单晶体和多晶体之间,表明[233]双滑移晶体的硬化行为比单滑移晶体更接近多晶体。[233]晶体的循环应力-应变(CSS)曲线在塑性应变幅γ_(pl)=3×10~(-4)～2×10~(-3)范围内出现1个准平台区。[233]晶体试样表面形成的两类宏观形变带(DBⅠ和DBⅡ)呈严格的正交关系,并随着外加应变幅的增加而不断发展。
In the range of plastic shear strain (γ_ (pl)) of about 10 ~ (-4) ~ 10 ~ (-2), the effects of coplanar double slip orientation [233] and single slip orientation [4 18 41 ] (Shimid factor Ω = 0.5) Cyclic deformation of copper single crystal. The initial hardening rate θ_ (0.2) of [233] crystal is lower when γ_ (p1) <2 × 10 ~ (-3), almost independent of the amplitude of strain. When γ_ (pl)> × 10 ~ (-3), θ_ (0.2) increases remarkably with the increase of γ_ (pl). When γ_ (pl) ≥3.5 × 10 ~ (-3), the cycle hardening curve of [233] appears in the secondary hardening stage, and the critical strain amplitude of secondary hardening is between single slip single crystal and polycrystal. It shows that [233] double-slip crystals behave more like polycrystals than single-slip crystals. The cyclic stress-strain curve of the crystal shows a quasi-flat zone in the range of plastic strain amplitude from 3 × 10 -4 to 2 × 10 -3. Two kinds of macroscopic deformation bands (DBⅠ and DBⅡ) formed on the surface of the crystal sample have a strict orthogonality relationship and develop continuously with the increase of the applied strain amplitude.