HIGH-TEMPERATURE EXPERIMENTAL CHARACTERISATION OF XN40F FOR LIFE PREDICTION OF SPF TOOLS

A. A. Deshpande (1) , S.B. Leen (1) , T.H. Hyde (1)

1 School of Mechanical, Materials & Manufacturing Engineering

This paper describes high temperature cyclic elastic-plastic testing of XN40F material for application to the life prediction of superplastic forming (SPF) tools. Cyclic plasticity material constitutive constants are identified from the high temperature tests across the range of 20oC to 900oC for representative predicted die conditions. These material constants are implemented within a transient, elastic-plastic-creep, thermo-mechanical analysis method for the die to furnish stress-strain-temperature cyclic data for creep-fatigue life prediction. A simulative thermo-mechanical fatigue (TMF) test, designed to represent the temperature and stress-strain cycling associated with the most damaging phase of the die cycle is presented and shown to give lives consistent with the predicted die lives.

Mots clés: Superplastic forming; plastic shakedown; heating-cooling cycles; part-forming cycles; thermo-mechanical fatigue and creep; major cycle; minor cycle; NLKH; TMF

Domaines: Mécanique [physics.med-ph]; Matériaux

A. A. Deshpande, S.B. Leen, T.H. Hyde. HIGH-TEMPERATURE EXPERIMENTAL CHARACTERISATION OF XN40F FOR LIFE PREDICTION OF SPF TOOLS. EuroSPF 2008, Sep 2008, Carcassonne, France. ⟨hal-00337989⟩