S45C/Si_3N_4/S45C接合体の残留応力と引張破断応力の関係  [in Japanese] Relationship between Tensile Fracture Stress and Residual Stress in S45C/Si_3N_4/S45C Bonded Joints  [in Japanese]

Tensile tests of S45C/Si_3N_4/S45C bar-type specimens which were bonded in 1987 and 1988 by a metalizing method, were conducted at room temperature in laboratory air. Using broken specimens, the effect of bonding-induced residual stress on the tensile fracture stress was investigated in this study. The main results obtained were as follows. (1)When the length of Si_3N_4 was nearly equal to the diameter of the specimen, the analytical results based on a finite-element method showed the validity of measuring the residual stress near the interface of the unbroken side. (2)The residual stress near the interface which was measured by an X-ray diffraction method was tensile and increased monotonously toward the interface. (3)The residual stress distributions were influenced by the diameter of the specimen, the length of Si_3N_4 and the year of bonding. (4) The tensile fracture stress decreased with the increase of the interface residual stress which was extrapolated from the residual stress distribution, and a linear relationship was found between them.