微压入仪的设计与柔度分析

摘要

Based on the instrumented indentation technique,an indentation tester with nanometer accuracy is presented which integrate the functions of driving, measuring,controlling and data-analyzing to-gether.The test's intermediate error is decreased by loading with voice coil actuator without transmissionmechanismThen the signal is acquired from high-precision capacitive displacement sensor and strain gauge load cell.Afterwards an closed loop control system based on PID algorithm is developed and control software is programmed.The instrument fiexity calibrated by finite element method is 1.8×l0-8m/N,much smaller than that of commercial instrument tester,thus the accuracy of the testing result is guaranteed sufficiently.%设计了基于仪器化压入技术的具有纳米测试精度的微压入仪,仪器集驱动、检测、控制和数据分析等功能于一体.采用音圈电机加载,无传动机构,减少了中间误差；通过高精度电容式位移传感器和应变式载荷传感器采集信号；设计了基于PID算法的闭环控制系统,编写了控制软件.通过有限元方法分析了加载时机架和试样的变形,标定了仪器柔度,仪器总体柔度约为1.8×10-8m/N,远小于目前商用仪器化压入仪的柔度,从原理上保证了测试结果的准确性.