极浅压入下纳米压痕仪针尖面积函数校准方法的研究

采用原子力显微镜直接扫描纳米压痕仪针尖法、球面拟合法和熔融石英标准样块的间接测量法对极浅压入下纳米压痕仪的针尖面积函数进行比较分析。实验表明,在极浅压入下,原子力显微镜直接法由于真实地反映了针尖尖端的几何形貌因而获得的面积函数更为准确可靠。建立了相应的数学模型,对于直接法测量中主要的误差,即由于原子力显微镜针尖曲率半径带来的误差进行了分析,结果表明在极小压入深度下压入深度越小,原子力显微镜针尖曲率半径带来的压痕仪针尖面积函数相对误差越大。

Study on the Calibration Method of the Tip Area Function of the Nanoindenter at Super Low Depth

Three methods are used to calibrate the tip area function of the nanoindenter at super low indentation depth,there are direct method based on atomic force microscope,spherical surface fitting method and indirect method based on the measurement results of the reference block of fused silica.It was revealed that tip area function calibrated by the direct method is mostly reliable and precise,of which the geometry morphology of the top end of the nanoindenter tip was truly fitted.Moreover,the corresponding mathematical model was established to analysis the main error of the AFM method,which was the error caused by the curvature radius of the atomic force microscope tip.The results show,under the super low indentation depth,the relative error of the tip area function of the nanoindentation is increasing with the decrease of indentation depth,which is mainly due to the curvature radius of the atomic force microscope tip.