DEVELOPMENT OF HIGH TEMPERATURE ULTRA-MICROINDENTOR USING LASER-PHASE-MODULATION-INTERFEROMETER

超微压头是目前唯一一种能够直接测量微区硬度和力学性能的方法，在材料开发和产品管理中具有广阔的应用前景。然而，目前的情况是，由于在较高温度下的技术困难，这种测量技术的推广落后。现有的压头微位移测量方法是通过电容间接测量的，热膨胀的影响会导致测量误差。本研究的目的是建立高温精细测量技术，利用最新的激光测量技术，通过直接测量压头与样品表面之间的相对位移来解决热膨胀问题。在第一财政年度（1995年），我们研制了一种用于测量垂直位移的激光相位调制干涉仪，并设计和试制了一种将激光束引入样品表面的压头。压头距中轴线1mm处有直径1mm的孔，孔内有半镜面。通过干涉反射镜反射的两束光束和样品表面，直接测量压头与样品表面之间的相对位移。在1996财政年度，我们将压痕机安装到现有的微压痕试验机上，并从各个角度估计了效率。最大分辨率为1nm。由于反射光束对光纤的入射角对分辨率有很大的影响，我们还发现了对样品台的斜率进行微调的必要性。指出，只要满足这些条件，就可以进行高温下的超微压痕试验，其程序和精度与室温下相同，避免了温度的影响。

Ultra-micro-indentor is the only one method for the direct-measurement of hardnesses and mechanical properties in micro area, and is expected to be applied to material-development and products-management. It is, however, the present situation that the generalization of this measurement-technique is behind because of the technical difficulties at relatively high temperature. In the existing technique, the micro displacement of indentor is indirectly measured by a electric capacitance, therefore the influence of thermal expansion causes errors. The purpose of the present study is the establishment of the fine measurement technique at high temperature, solving the problem of thermal expansion with the direct measurement of the relative displacement between the indentor and sample surface, using a up-to-date laser measurement technique. In the first fiscal year (1995), we developed a laser-phase-modulation-interferometer for the measurement of vertical displacement, and made a design and a trial manufacture of an indentor which introduce the laser beam to the sample surface. The indentor have a hole with 1mm diameter at 1mm distance from the central axis, and have a half-mirror within the hole. The relative displacemet between the indentor and the sample surface is directly measured by interfering the two beams reflected by the mirror and the sample surface. In the fiscal year of 1996, we installed the indentor to an existing micro indentation testing machine and estimated the efficiency from various points of view. The maximum resolution is 1nm. We also found the necessity of fine adjustment of the slope of the sample stage, because the incident angle of the reflected beam to the optical fiber strongly influence the resolution. It is pointed that, if such conditions are satisfied, the ultra micro indentation test at high temperature is available with the same procedure and accuracy as at room temperature avoiding the temperature influence.