| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
In industrial field, R.A.Glendhill et al. (J.Adhesion, 1980, vol.11, p3-15) developed a method for predicting the joint durability which only required the information about the diffusion coefficient and equilibrium water uptake in adhesives and the short-term mechanical properties. The object of this study is to determine whether it is possible to use this analysis for predicting the joint durability of tensile butt joints, consisting of a dental 12% Au-Ag-Pd alloy bonded with a commercial 4-META dental adhesive resin cement immersed in water at 20ﾟ,37ﾟ,50ﾟ and 60ﾟC
The amount of water penetrated at the interface between the resin cement and the alloy was calculated from the Fick's equation for water absorption, and the diffusion coefficient and equilibrium water uptake in the cement. The stress-intensity factor was obtained according to the ASTM standard, and the tensile adhesive strength immersed in water at 60ﾟC for three days was also determined. Using these values and the water concentration profile, values of joint's fracture stress were then deduced as a function of the temperature and immersion time prior to testing. To make sure that the prediction of the joint durability is appropriate, the theoretically predicted values were compared to the experimentally determined strength values at 60ﾟC.The agreement between the prediction and experimental measurements was good.
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