features-of-thermally-stressed-partsTarnishingIndicatessurface embrittlementOxidationContaminants anddeposits- "Secretions" in infiltrated sintered materials- Local fusing of meltsFracture symptoms:- Growth lines- Oxidation- Fracture originHardnessDeformation through - Residual stresses Buildup or breakdown- CreepHardness:- Absolute value- OrientationResidual stresses:- Type, size- OrientationImprints for metallography and SEM- Pitting samples- EtchingExternal appearance and non-destructive testingof thermally stressed parts:Cracking:- Gaping, closed- Continuous, branched- Single crack, crack field- Crack location in part, relative to machining marks etc. Local melting andbreaking open ofsolder seamsSplashed-on meltedmaterial drops- Weld splash- From machining (high-speed machining)