INVESTIGATION ON THIN-WALL EFFECT OF A DIRECTIONALLY SOLIDIFIED SUPERALLOY BY USING TUBULAR SPECIMENS
INVESTIGATION　ON　THIN－WALL　EFFECT　OF　A　DIRECTIONALLY　SOLIDIFIED　SUPERALLOY　BY　USING　TUBULAR　SPECIMENS

The thin-wall effect of DZ25G, a directionally solidified (DS) superalloy, has been studied by ustng tubular investment cast thin-wall specimens with shape and wall thickness near the air-cooled hollow blades.The results show that the stress-rupture properties of the thin-wall specimens (thickness 0.8, 1.2 and 1.6 mm) are equivalent to the standard ones (diameter 5 mm),i.e., under the experimental conditions in this study the alloy DZ25G has insignificant thin-wall effect. It is apparent that the resulte are different from previous work. In the paper the reasons resulting in the difference were discussion in terms of the specimen manufacture process and thus microstructure feature.