Material defects in a PM-Nickel-base superalloy

The purpose of this work was the determination of the type, size and frequency of defects in a nickel-base superalloy (U700). In order to obtain a higher frequency of defects compared to the standard material the alloy was deliberately doped with organic defects (rubber particles). Eight different types of defects were documented and their influence on the surrounding material investigated by energy and wavelength dispersive x-ray analysis. With the aid of a fully automated scanning device the intersection areas of the defects were dtermined (shape and size of the circumferential ellipses and the distribution of linear intercepts). The spatial defect size distributions were derived from the distributions of intercept areas and evaluated statistically. The resulting defect distributions were compared to those of unsieved powder.