Homogeneity of Deformation - Influence of Specimen Geometry and Lubricants -- Deformation Dilatometer Investigations
Ulrich Lorenz und Jens-Jörg Esser, Aachen
ABSTRACT Besides the measurement of phase transformations in dilatometers just by cooling, the importance of pre-straining of dilatometer samples has increased to measure directly the influence of deformation on phase transformations. Hence reliable deformation conditions have to be given in modern deformation dilatometers. Scope of the investigations is a systematic optimisation of test conditions in a deformation dilatometer. One hit and two hit compression has been tested on three different steel grades, i.e. a quenched and tempered steel, a structural steel and a tool steel. The homogeneity of uniaxial compression tests was optimised by investigating the influence of different geometries of the fronts of cylindrical specimen in combination with different lubricants. The homogeneity was evaluated by sample geometry and the distribution of strain and temperature over the specimen area. The results of the presented studies allow achieving better results of uniaxial deformation tests and assure a homogeneous straining of investigated samples.
Publication Source: Materialprüfung, ISSN: 0025-5300
Issue: 2003-10, pp -
Publisher: Carl Hanser Verlag München
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