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Abstract. In order to reduce costs and increase the operating temperatures in aero-turboengines and space propulsion systems, net-shape or near net-shape production processes have been developed for static parts through HIPing (Hot Isostatic Pressing) of nickel base superalloys prealloyed powders. The presented results hereafter are related to the manufacturing processes and the mechanical properties (tensile, creep and LCF) characterisation. The effects of net shape surfaces and of surface conditioning have been investigated too. Examples of actual parts (CFM56 turbine casing and Vulcain rocket engine gas generator) illustrate the presentation. This study has confirmed the interest of this production route and future potential for development.

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In order to assess the life of Ti-6Al-4V components at 20 K supporting local plastic deformation during nominal loading, it is necessary to quantitatively describe the effect of the induced heat generation. Linear stability analysis is applied to describe the onset of instability for the experimental conditions considered. Then, the thermomechanical coupling is implemented in a finite element code. It is shown that the model properly describes the experimental tensile tests performed at 20 K under helium gas. It is able to restore the main features described in the literature. The model is applied to discuss the development of the heterogeneous pattern of deformation through the specimen at various imposed cross-head velocities. The transition from propagative to random non-propagative localized bands is observed. The proposed finite element model is shown to be a powerful tool to analyse in-service components in the cryogenic range.