The present paper examines the temperature sensitivity of tensile twinning in a magnesium single crystal during nanoindentation of the prismatic plane. High temperature indentations from 25 °C to 250 °C were employed on a well polished magnesium single crystal {10-10} plane. For a indentation curve displaying a pop-in, a single twin was seen on the sample surface using Atomic Force Microscopy (AFM) imaging. For indentations that produced no pop-in, no twinning was observed. We thus conclude the pop-in arises from a twinning event in the present case. With increasing temperature, the mean pop-in load (measured from 200 repeat indentations of each testing temperature) drops markedly. This is interpreted by the thermal activation of nucleation of lattice dislocations, which immediately trigger a twinning event. Thermal activation analysis yields activation energies that are consistent with this idea. With increasing temperature the pop-ins became deeper and the twins, after further indentation, showed more growth. It is likely that non-basal slip is activated in the stress concentrations that arise during twinning and the thermal activation of this slip accounts for the observed temperature effects. It is concluded that in interpreting the temperature sensitivity of twinning stresses, any associated lattice dislocation activity must be considered.

本论文研究了在棱柱平面的纳米压痕过程中镁单晶中拉伸孪晶的温度敏感性。在抛光良好的镁单晶 {10-10} 平面上采用 25 °C 至 250 °C 的高温压痕。对于显示弹出的压痕曲线，使用原子力显微镜 (AFM) 成像在样品表面上看到了一个双胞胎。对于没有产生弹出的压痕，没有观察到孪晶。因此，我们得出结论，在本案中，pop-in 是由孪生事件引起的。随着温度的升高，平均弹入载荷（从每个测试温度的 200 次重复压痕测量）显着下降。这可以通过晶格位错成核的热激活来解释，这会立即触发孪晶事件。热活化分析产生与这个想法一致的活化能。随着温度的升高，pop-ins 变得更深，双胞胎在进一步压痕后显示出更多的生长。非基础滑移很可能在孪晶期间出现的应力集中被激活，这种滑移的热激活解释了观察到的温度效应。得出的结论是，在解释孪晶应力的温度敏感性时，必须考虑任何相关的晶格位错活动。非基础滑移很可能在孪晶期间出现的应力集中被激活，这种滑移的热激活解释了观察到的温度效应。得出的结论是，在解释孪晶应力的温度敏感性时，必须考虑任何相关的晶格位错活动。非基础滑移很可能在孪晶期间出现的应力集中被激活，这种滑移的热激活解释了观察到的温度效应。得出的结论是，在解释孪晶应力的温度敏感性时，必须考虑任何相关的晶格位错活动。