QUENCHING, THERMAL AND RESlDUAL STRESS IN PLASMA SPRAYED DEPOSITS： NiCrAlY AND YSZ COATINGS

摘要

Residual stress is an important factor inthermally sprayed deposits which affects bothprocessing and performance. High stress magnitudesand/or concentrations can undermine the structuralintegrity of sprayed parts and impair theirfunctionality. Therefore, it is important to know thestress state, under- stand its generation and be ableto control it. Results of experimental stressdetermination in plasma sprayed deposits arepresented. Neutron diffraction as a non-destructiveand phase-distinctive measurement method was used todetermine residual stress profiles in thick NiCrAlYand yttria-stabilized zirconia (YSZ) deposits.Measurements were complemented with calculationsbased on experimentally determined materialproperties, which allowed for separation of quenchingand thermal stress contributions to final residualstress. Since the application of neutron diffractionto plasma sprayed deposits is relatively novel,certain verification measurements were performed.Specimens were prepared at two different depositiontemperatures, to determine the effect of temperatureon the stresses and relevant deposit properties.