抄録
Sintered Fe-Cr alloy containing TiN particles has high wear and heat resistance. These materials have been developed for the valve seat insert, which is a part of automobile diesel engines. In this study, X-ray and neutron diffraction techniques were used to carry out residual stress measurements of composite material, in order to evaluate the stresses in each phase. The influence of inclusions (titanium nitride) on the residual stress was examined. Measured data obtained from both phases were compared to the micromechanics model based on Eshelby's approach and the Mori-Tanaka theorem. The range of applicability of the theoretical expectation in the determination of the residual stress in composite material was investigated. It was found that (1) in the case of the neutron diffraction technique, the matrix 110, 200 and 211 diffractions were observed in the matrix (Fe-Cr)phase. The 111, 200, 220, 311 and 222 diffraction peaks were observed in the TiN phase. (2) The change in the stress of each phase under an elastic load was examined. Individual phase stresses in the matrix and TiN increase proportionally with the applied stress, and the ratio of the amount of change to applied stress indicates that the TiN phase is more abundant the matrix.
