Untersuchungen zum Sproedbruchverhalten intermetallischer Ti-Al-Si-Nb-Legierungen

The object of this paper is the fracture behaviour of three Ti-Al-Si-Nb alloys. Fracture mechanical data are experimentally determined and their statistical properties are investigated. To describe the fracture process of disordered heterogeneous brittle materials a statistical model was developed, based on damage mechanics. With the aid of this model it was possible to attribute the fracture behaviour, the fracture mechanical data and their statistical properties to the microstructure of the materials studied. (orig.)In dieser Arbeit wird der Versagensvorgang dreier Ti-Al-Si-Nb-Legierungen experimentell untersucht; es werden bruchmechanische Kennwerte ermittelt und bruchstatistische Untersuchungen durchgefuehrt. Ein schadensmechanisches Modell zur Beschreibung des Versagensvorgangs sproedbrechender Materialien wird entwickelt, mit dessen Hilfe ein tieferes Verstaendnis fuer den Zusammenhang zwischen Gefuegeaufbau, Versagensvorgang und Auspraegung makroskopischer Bruchkennwerte sowie deren statistischem Verhalten ermoeglicht wird. (orig.)60 refs.Available from TIB Hannover: RA 3251(95/E/14) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Engineering estimation of the lower bound toughness in the transition regime of ferritic steels

A simple engineering method for estimating a lower bound fracture toughness in the ductile-to-brittle transition region is presented. It is based on empirical evidence that the lower tail of the failure probability versus fracture toughness curve tends to be a straight line rather than a Weibull curve. Fitting the lower tail by a straight line, however, gives an engineering lower bound at a theoretical failure probability of zero. The method enables one to obtain lower bounds using small data sets of three or four specimens. (orig.)First published in 'Fatique and Fracture of Engineering Materials and Structures (1998), 21, p. 1273-1278'Available from TIB Hannover: RA 3251(98/E/70) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman