压电驱动型微纳米压痕测试装置的设计与试验研究

Design and Experimental Investigation of PZT-driving Type Micro/nanoindentation Device

集成压电叠堆和柔性铰链设计一种微纳米压痕测试装置,分析测试装置的原理、组成和工作过程。该装置在压入方向上可实现0.05～30μm范围内线性位移输出,在无隔振和未做恒温处理的试验环境,位移传感器示数波动小于10 nm。提出一种新的机架柔度测试方法,利用该方法得到测试装置的机架柔度值为4.8 nm/mN。熔融石英材料压痕试验结果验证测试装置和机架柔度获取方法的可行性。对测试装置进行校准,利用校准后的测试装置对单晶硅片(100)晶面进行压痕试验,对应于最大压入载荷49.60 mN,当压入载荷卸载至18 mN时压痕曲线出现典型的pop-out现象,说明测试装置对于材料结构的细微变化具有较高的分析能力。根据Oliver-Pharr相关理论,计算得到单晶硅片(100)晶面在最大压入载荷为49.60 mN时的硬度为16.29 GPa,弹性模量为181.63 GPa。

Micro/nanoindentation device is designed by integrating the piezoelectric stack and the flexure hinge. Principle, components and working process of the developed device are analyzed. The proposed device can realize linear displacement output in the range of 0.05-30 μm. In the experimental environment without vibration isolation and constant temperature treatment, fluctuation of the measured displacement is less than 10 nm. A novel method for measuring instrument compliance is proposed. Via this method, compliance of the developed device is obtained and it is 4.8 nm/mN. Indentation testing results of fused quartz verify the feasibility of the developed device and the proposed method for measuring device compliance. The device is calibrated. The indentation experiment of single crystal silicon on the （100） crystal surface is carried out by the calibrated device. Corresponding to the maximum indentation load of 49.60 mN, pop-out phenomenon appears when the indentation load decreases to 18 mN, which indicates that the device has the ability to distinguish small changes of material structures with high resolution. Based on the Oliver Pharr method, hardness and elastic modulus of the used single crystal silicon are 16.29 GPa and 181.63 GPa respectively when the indentation load is 49.60 mN.