In-Situ Observation of Thermal Deformation Behavior of Tin-Kover Joints by Laser Beam Microscopy and Thermo-Elasto-Plastic Analysis
Hiroyuki TANAKA, Hiroshi OKADA and Toshio NARITA
Abstract:The laser beam microscopy was applied to the in-situ observation of thermal deformation of the tin-Kover joint in heating and cooling processes over the temperature range between 298 and 423K. The surface displacement of the tin-Kover joint was measured with accuracy at 0.1ƒÊm, and the crack initiation and propagation of the tin-Kover joint was observed in-situ during the heating and cooling the joint. Using the axial symmetric 2-dimensional thermo-elasto-plastic analysis, the stress-strain distributions were calculated in the heating and cooling processes over the temperature range between 298 and 423K. The observed displacement and calculated one agreed in the heating process, whereas the calculated displacement differed from the observed one in the cooling process. The calculated displacement accumulated in the thermal cycle, not returning to the initial position, and the correlation between the observed displacement and calculated one in heating and cooling processes was discussed. Key Words:In-situ observation, Laser beam microscopy, Thermal deformation, Thermo-elasto-plastic analysis, Tin-Kover joint