Abstract: heinteracteach other among three kindsofthermalresidualstresses were analyzed firstly. Theresultsshown thatthe presenceof microstressandthermal mismatch stresshad noinflu enceon the measurement of macrostress, but macrostress can affect the measured value of thermal mismatch stress. Theeffectofthicknessofspecimen on thermalresidualstresses was discussed. Macrostresscan be neglected in thin specimen, thermal mismatch stressincreased with quenchingtemperatureincreasing, andobtainedtheir maximum valuesat400 ℃,then decreased . Forthethickspecimen, thecompressive macrostressatthesurfaceincreased with the quenching temperature increasing. The changing tendency of thermal mismatch stresswith quenchingtemperature wasquite differentcompared withthethinspecimens, which ob tainedtheir minimum valueat400℃.

Key words: thermalresidualstresses, X ray diffraction, SiCw/ Alcomposites