MECHANO-ELECTROCHEMISTRY OF MICRO-SURFACE AREA OF MATERIALS

在pH 8.4硼酸盐溶液中对单晶铁（100）表面进行了纳米压痕试验，测量了铁表面的载荷-深度曲线，并由此评估了铁表面的硬度和弹性模量等力学性能，为建立机械-电化学基础知识提供了基础知识。铁表面的硬度随纳米表面积的位置而波动。而在被动电位区，平均硬度值在0.25 V时最小。在0.25 v以上电位下，平均硬度随电位（即钝化膜厚度）的增加而线性增加。利用平均硬度与薄膜厚度之间的线性关系，可以将薄膜本身的硬度与基体铁的硬度区分开来。此外，在pH 8.4硼酸盐溶液中，对1.0 V钝化的单晶铁（100）和单晶铁（110）表面进行了纳米压痕试验，进一步研究了硬度与表面晶向的关系。然而，单晶铁（100）和单晶铁（110）表面的硬度没有显著差异。测定了不同电解质溶液中经阳极氧化的多晶钛表面硬度随阳极氧化膜形成电位的变化。当成膜电位达到8 V时，硬度随成膜电位的增大而增大。硬度在8v以上迅速下降，薄膜在8v以上发生局部击穿。此外，在硫酸中阳极氧化的钛表面硬度最大。采用激光束偏转法测量了钛阳极氧化膜中产生的应力，研究了膜中应力与硬度的关系。在硫酸中，钛的阳极氧化膜产生最大的压应力。因此，发现压应力与硬度之间存在良好的相关性。在高于8 V的电位下，压应力部分释放，阳极氧化膜局部击穿。在8v以上电位处，硬度迅速下降是由于阳极氧化膜局部击穿导致压应力部分释放所致。少

Nanoindentation tests were performed for the single crystal iron (100) surfaces electrochemically controlled in pH 8.4 borate solution to measure the load-depth curves from which the mechanical properties such as hardness and elastic modulus of the iron surfaces were evaluted to obtain the fundamental knowledge for estabilshment of mechano-electrochemistry. The hardness of the iron surfaces was fluctuated depending on the position of nano-surface area. The average value of hardness, however, took a minimum at 0.25 V in the passive potential region. At the potential above 0.25 v, the average hardness increased linearly with increasing the potential, I.e., the thickness of passive film. The hardness of film itself could be separated from that of the substrate iron by using the linear relation between average hardness and film thickness. Moreover, the nanoindentation tests were performed for the single crystal iron (100) and (110) surfaces passivated at 1.0 V in pH 8.4 borate solution to … More investigate the depedence of hardness on crystal orientation of the surface. However, no significant differences in hardness was observed between single crystal iron (100) and (110) surfaces.The hardness of the polycrystalline titanium surfaces subjected to anodic oxidation in various electrolyte solutions was measured as a function of formation potential of anodic oxide film. The hardness increased with increasing the film formation potential up to 8 V. The hardness decreased rapidly above 8 V at which the local breakdown of the film would take place. Moreover, the largest hardness was observed for the titanium surfaces subjected to anodic oxidation in sulfuric acid. The stresses generated in the anodic oxide film on titanium were measured by a laser-beam deflection method to investigate the relation between stress in the film and hardness. The largest compressive stresses were generated in anodic oxide film on titanium in sulfuric acid. Therfore, it is found that there is a good correlation between compressive stress and hardness. The partial release of the compressive stresses were observed at the potential above 8 V at which the local breakdown of anodic oxide film took place. The rapid decrease in hardness at the potential above 8 V was ascribed to the partial release of compressive stress ue to local breakdown of anodic oxide film. Less