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在塑性分切应变幅(γ_(pl))为1.2×10~(-4)～6.5×10~(-3)范围内,系统研究了临界双滑移取向[017]铜单晶体的循环形变行为,并将其与[034]临界双滑移及[001]和[011]多滑移取向单晶体的结果进行了比较。当γ_(pl)<2×10~(-3),[017]晶体的初始硬化速率θ_(0.2)几乎与应变幅大小无关。当γ_(pl)>2×10~(-3),θ_(0.2)随γ_(pl)的增加而显著增大。[017]晶体的循环应力-应变(CSS)曲线不呈现平台区,但在塑性应变幅范围(5.0×10~(-4)～1.5×10~(-3))内近似出现一准平台。[017]晶体的滞后回线形状参数V_H在γ_(pl)=9.4×10~(-4)下可用来确定驻留滑移带(PSB)的萌生应力,其萌生应力约为39MPa。而在其他一些应变幅下,V_H与PSB的形成无明显对应关系。对于取向位于标准取向三角形001/011边上的铜单晶体,由011→001方向,其初始硬化速率逐渐升高,CSS平台行为发生明显的变化,从类似单滑移晶体的结果过渡到类似多晶体的结果,即:由较宽的平台区的出现([011]晶体),到平台区的缩短([034]和[012]晶体),再到准平台区的出现([017]晶体),直至平台区的完全消失([001]晶体)。
The cyclic strain behavior of copper single crystal with critical twin slip orientation [017] was studied systematically in the range of 1.2 ~ 10 ~ (-6) And compared it with the results of [034] critical double slip and [001] and [011] multi-slip oriented single crystals. When γ_ (p1) <2 × 10 ~ (-3), [017] The initial hardening rate θ_ (0.2) of the crystal is almost independent of the strain amplitude. When γ_ (pl)> 2 × 10 ~ (-3), θ_ (0.2) increases remarkably with the increase of γ_ (pl). The Cyclic Stress-Strain (CSS) curve of the crystal does not exhibit a plateau region, but a quasi-plateau appears approximately within the range of plastic strain amplitude (5.0 × 10 -4 to 1.5 × 10 -3). The hysteresis loop shape parameter V_H of the crystal can be used to determine the initiation stress of the resident slip band (PSB) under the condition of γ_ (pl) = 9.4 × 10 ~ (-4). The initiation stress is about 39 MPa. At other strain amplitudes, there is no obvious correspondence between the formation of V_H and PSB. For the monoclinic copper single crystal orientated on the 001/011 side of the normal orientation triangle, the initial hardening rate gradually increases from 011 → 001, and the behavior of the CSS platform changes obviously. The transition from the single-slip crystal to the polycrystalline (Ie, [017] crystals), the shortening of plateau regions ([034] and [012] crystals) and the presence of quasi-plateau regions Until the platform area disappears completely ([001] crystal).