In-situ SEM nanoindentation and nanoscratch testing methods are commonly used for mechanical characterization and investigation of the deformation and failure mechanisms of coating materials with micro- to nano-scale thicknesses. However, existing SEM-based integrated nanoindentation and nanoscratch instruments have two main limitations. First, the measured mechanical properties of the coating materials at micro- to nano-scale thicknesses are highly sensitive to surface roughness. Second, the existing SEM-based instruments lack the capability to acquire the morphology of residual imprints in real-time after nanoindentation and nanoscratching. In this study, a novel SEM-based integrated nanoindentation, nanoscratch, and atomic force microscopy (AFM) instrument, namely, NMT-AFM was proposed, developed and fabricated. The self-sensing piezoresistive cantilever (PRC) was selected as the AFM force sensor owing to its miniaturization ability. However, the resistance of the PRC sensor fluctuated because of the electron irradiation from SEM, resulting in the continuous drift of the PRC signal during SEM imaging. To overcome this limitation, a mechanism of PRC signal drift inside SEM was analyzed for the first time, and a PRC signal drift reduction method was proposed based on the mechanism analysis. The experimental results indicated that the PRC signal drift was reduced to 2nm in 2 minutes by applied external voltage value U_A of 30V to modified PRC, which proved the proposed mechanism of PRC signal drift during SEM imaging. Finally, the X-Y fine nanopositioner angle calibration test using AFM calibration chip VGRP-UM and the nanoindentation/nanoscratch characterizations of the TiAlSiN coating material were conducted.

原位SEM纳米压痕和纳米划痕测试方法通常用于机械表征和研究具有微米级至纳米级厚度的涂料的变形和破坏机理。但是，现有的基于SEM的集成纳米压痕和纳米划痕仪器有两个主要限制。首先，在微米级至纳米级厚度下测得的涂料机械性能对表面粗糙度高度敏感。其次，现有的基于SEM的仪器缺乏在纳米压痕和纳米划痕后实时获取残留印记形态的能力。在这项研究中，提出了一种新型的基于SEM的集成纳米压痕，纳米划痕和原子力显微镜（AFM）仪器，即NMT-AFM。由于其小型化能力，自感压阻悬臂（PRC）被选作AFM力传感器。但是，PRC传感器的电阻由于SEM的电子辐照而波动，从而导致SEM成像期间PRC信号的连续漂移。为克服这一局限性，首次分析了SEM内部PRC信号漂移的机理，并在机理分析的基础上提出了一种PRC信号漂移降低的方法。实验结果表明，通过施加外部电压值，PRC信号的漂移在2分钟内减小到2nm 导致SEM成像期间PRC信号的连续漂移。为克服这一局限性，首次分析了SEM内部PRC信号漂移的机理，并在机理分析的基础上提出了一种PRC信号漂移降低的方法。实验结果表明，通过施加外部电压值，PRC信号的漂移在2分钟内减小到2nm 导致SEM成像期间PRC信号的连续漂移。为克服这一局限性，首次分析了SEM内部PRC信号漂移的机理，并在机理分析的基础上提出了一种PRC信号漂移降低的方法。实验结果表明，通过施加外部电压值，PRC信号的漂移在2分钟内减小到2nm修改后的PRC的30 V U _A证明了拟议的SEM成像期间PRC信号漂移的机理。最后，进行了使用AFM校准芯片VGRP-UM的XY精细纳米定位角校准测试，并对TiAlSiN涂层材料的纳米压痕/纳米划痕进行了表征。