Corrosive Esophagitis

Abstract

The classical sin²Ψ-method has been applied to investigate the main processing steps of a powder manufacturing route. For this investigation the hexagonal metal rhenium has been chosen to study the residual stress evolution within powder densification and the subsequent sintering. Despite the small penetration depth of the X-ray beam into rhenium it will be demonstrated that, the analysis of the sample on the basis of a biaxial residual state (σ33=0) can lead to physically totally unrealistic results within the sin²Ψ-technique. Even in those cases, where the appearance of the results derived by standard evaluation procedures (slopes within the sin²Ψ-plots) seems to be clear at a first glance, the uncritical acceptance can lead to serious errors. The differentiation demands a very detailed investigation of the sample in different diffraction geometries. More complex analysis routines, like the Rietveld based “combined analysis”, can clear without ambiguity concerning the stress state and enable the doubtless distinction between compressive/tensile and biaxial/triaxial.