The stress rupture properties and the fracture character of thin wall specimens of DD6 single crystal superalloy with ［001］ direction were investigated at 980℃ and 250MPa. Result showed that stress rupture life of the thin wall specimens was less than that of the standard sample

which exhibited thin wall effect obviously. There was a function relationship between thickness and stress rupture life. The edge zone of the fracture surface of thin wall specimens was oxidized seriously

while the inside zone was affected by microvoid coalescence fracture. The fracture of thin wall specimen was indicated by coalescence of the “surface oxidation-crack initiating-crack growth” and “inside creep damage”. The extent of surface oxidation was more serious

while the stress rupture life was shorter.