Size dependent residual stress field of composite ceramic with eutectic interphases
Composite ceramics with eutectic interphases fabricated through SHS process can acquire high toughening and good plasticity.Composite ceramics with eutectic interphases were mainly composed of eutectic ceramic rod with random orientation,in which nano-fibers with eutectic interphases are dispersed within the ceramic matrix.Our study is based on a model in which a rod-shaped equivalent composite inclusion is embedded in an infinite effective medium,and the equivalent composite inclusion is composed of a fiber with eutectic interphase and matrix -atmosphere.We consider that the mechanical property of the effective medium is same as composite ceramics with eutectic interphases.Fiber,eutectic interphase,matrix-atmosphere and effective medium composed of four-phase-model.First,four-phase-model method is used to study residual stress field of composite with eutectic interphases aroused thermal inconsistency.Then,considering matrix,eutectic interphase and fiber are isotropy,the residual stress distribution of composite ceramic with eutectic interphase is obtained.Finally,the size dependence of residual stresses is analyzed.The results show shat the resid-ual-stress-field in the eutectic ceramic rod relates to the stiffness,thermal expansion coefficients,shape and volume content of inclusions and interphases in the eutectic ceramic rod.The residual stresses in matrix are compressive and dependent on the diameter of fiber.Their absolute value will increase as the diameter of nano-fiber increase.When the diameter of nano-fiber is bigger than 100nm,the residual stresses in matrix are approximately constants.The residual stresses in eutectic interphase are compressive and not almost dependent on the diameter of fiber.The residual stresses in fiber are tensile and dependent on the diameter of fiber.Their value will decrease when the diameter of nano-fiber increase.When the diameter of nano-fiber is bigger than 50nm,the residual stresses in nano-fiber are approximately constants.The analysis result will lay a foundation for damage evolution research of composite with interphases.
Size dependent Residual stress field Rod-shaped eutectic Nano fiber inclusion Four-phase-model method
Xiequan Liu Xinhua Ni Zhaogang Cheng Baofeng Li Lei Zhao
Department of Basic Course,Mechanical Engineering College,Shijiazhuang 050003,China
国际会议
成都
英文
397-401
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）