ニッケル合金薄膜の粒成長を利用した高温繰返し応力測定法

抄録

When an electrodeposited copper or nickel foil is subjected to a cyclic loading, grain growth occurs in the foil. If the relationship between the grain density, stress amplitude and number of cycles has been calibrated beforehand, it is possible to measure the stress amplitude based on the grain density. Since the thermal recrystallization occurs in the foil when the ambient temperature rises, the upper limit of the ambient temperature is limited to 80 oC and 250 oC for the copper foil and the nickel foil, respectively. In this paper, the possibility of stress measurement at higher temperature was examined by applying nickel alloy foil. First, the nickel alloy foil was heat treated under various conditions. Then the grain size was analyzed using EBSD in order to check whether grain growth occurred. Moreover, the pulsating tension tests were carried out under 350 to 450 oC, and the grain size was also analyzed. It was revealed that the nickel alloy foil was recrystallized at a temperature of 350 to 450 oC. Moreover, the grain growth due to cyclic loading could also be confirmed under 350 to 450 oC. Therefore, the possibility of stress measurement by nickel alloy foil under high temperature environment was suggested. A calibration equation for stress measurement was proposed based on the grain size equation proposed for the recrystallization.