Applications Of Micro-Raman Spectroscopy In Micro-scale Mechanical Test

With the rapid development of materials science, the advanced composites and micro-devices which possess micro/nano-structure have been used more and more widely, and they become more complicated, which lead to some new mechanical problems inevitably. Thus, how to measure the mechanical quantities such as stresses and strains of these micro-elements attracts great interest. Up to now, existed experimental techniques, mostly measure at macro-scale, are difficult to apply to micro-scale fields, such as MEMS. Micro-Raman Spectroscopy(MRS)has many special advantages of nondestructive, non-contact, high spatial resolution (1μm), broaden spectrum range, and Raman shift unaffected by the frequency of laser source. Furthermore, one of the most interesting characteristics of Raman spectrum is sensitivity to strain in the sample. When the material is under strain, this may cause a Raman shift, by which strain may be possibly direct measure. The underlying basis of micro-Raman spectroscopy for strain measurement is that Raman shift reflects the atomic spacing change, namely the strain information.In this thesis, Micro-Raman technique is used to the micro-droplet test for the composite (Kevlar-29 aramid fibre/epoxy resin), the measurement of film residual stress and the study of piezoelectric effect quartz sand. Then it concludes three parts:1. The effect of geometry of the end of the sample on the distribution of the stress field has been investigated. The micro-droplet test into which MRS is introduced has been conducted for the cases of two kinds of end anglers, then the distributions of the fibre axial stress, the interfacial shear stress and the stress transfer length have been obtained. Form the obtained experimental results, we can find that the geometrical characteristics can affect significantly the stress distributions in the micro-droplet test.2. The residual stress in uncooled infrared focal plane arrays(UIRFPA) which composes of SiO2 film and Si matrix has been investigated by using MRS. The process of the thermal oxidation may lead to the residual stress which has an important effect on the properties of the micro-elements. Therefore, it is necessary to measure the film residual stress. The distribution of the residual stress along the cross–section of the matrix has been obtained by MRS, and then the film residual stress is obtained by means of the force equilibrium. In addition, the X-ray diffraction is...