纳米压痕技术在工程材料研究中的应用

Application of Nano-indentation in Engineer Materials Research

纳米压痕技术具有高灵敏度、操作简单等优点,可以在微纳尺度上获得块体材料、薄膜以及涂层等的多种力学性能参数。尤其随着材料基因组技术的推广,其将成为应用越来越广泛的力学性能表征方法。本研究介绍了纳米压痕技术的Oliver-Pharr方法原理,以及其在载荷-位移、硬度、弹性模量、断裂韧度、蠕变性能、残余应力、纤维界面性能表征方面的应用。在使用过程中仍存在一些问题需要注意和进一步研究:纳米压痕技术获得的力学性能参量需要考虑其测试模型的适用性;材料表面加工过程需要很高的技术及一致性,以最大减小甚至消除材料表面状态及物理特征对测试结果准确性和重复性的影响;由于测试位置较难精确定位,标准压头外形尺寸存在偏差以及设备本身的热漂移,纳米压痕测试重复性差。

With the advantages of high sensitivity and simple operation,the nano-indentation technology can be used to obtained micro-and nano-size mechanical properties of block materials,films,coatings and so on. Especially with the advancement of material genome technology,it is more and more widely used to characterize mechanical properties. In this paper,the OliverPharr principle and the application of nano-indentation in the load-displacement,hardness,elastic modulus,fracture toughness,creep properties,residual stress and interfacial characterization are introduced. Some existing problems of the nano-indentation technology are analyzed： The mechanical property parameters testing by nano-indentation technology should take into account the applicability of the test model; In order to minimize or even eliminate the effect of the surface state and physical characteristics of material on the accuracy and repeatability of the test results,the processing of material surface requires high technology and consistency; The nano-indentation test has poor repeatability,because of the difficulty in accurately locating the test position,the size deviation of the standard indenter and the thermal drift of the device itself.