Einfluß der Oberflächennachbehandlung auf die Schwingfestigkeit von gegossenen Aluminiumschaufeln für Axialventilatoren

The influence of cast defects on the fatigue behaviour is ascertained taking blades made of G- AlSi 10 Mg wa in the sand cast process. An improvement of fatigue strength is not only achievable by limiting casting defects such as surface pores, cavities and internal voids but also of post casting treatments like shot peening or hipping. The treatments shot peening or hot isostatic pressing improve the fatigue strength by about 15 to 17 %, and the fatigue life by a factor of two in comparison to the untreated material state. But this rate of improvement due to compressive residual stresses in the case of shot peening and due to the elimination of pores by hipping is within the scatter of fatigue strength of Tsubsigma equals 1:1.50 not very significant and economically not justified.