较浅压入下针尖曲率半径对纳米压入硬度影响研究

Study on Different Curvature Radius Tips on the Nano Indentation Hardness at Super Low Depth

基于3种不同曲率半径压头针尖对熔融石英进行纳米压入,用原子力显微镜(AFM)直接法测得压头针尖的面积函数及针尖曲率半径。研究表明,在极浅压入条件下,压头曲率半径的变化会导致硬度值的测量误差,曲率半径越小的压头针尖随接触深度的变化会更快得到真实值;相同的压入深度,曲率半径小的压头针尖测得的压入硬度值比曲率半径大的测得的压入硬度值更接近其真实值。

Nano indentation experiments that were carried out with three different curvature radius tips on fused silica. The curvature radius and the area function of the tips is measured directly by the AFM method. In shallow indentation conditions, the measurement errors of indentation hardness would be affected by the variation of curvature radius of tip. The smaller the curvature radius of the tip , the faster obtained of the true indentation hardness as the increase of contact depth. As the same small indentation depth, the tested hardness is closer to its true value under a smaller curvature radius tip than that of larger one.