Abstrakt

Measurement of the densities of various cast refractory cobalt-based alloys; Influence of their chemical compositions and of the nature of the carbides if any

PatriceBerthod,Thierry Schweitzer

The volume mass of the refractory metallic alloys used in transportations, aeronautical and others, or for the hottest rotating tools in energy production or industrial processes, is frequently of importance due to the impact on energy economy and requirements in mechanical resistance. This is particularly true for superalloys, which are already rather dense and the density of which may be increased by the presence of strengthening heavy elements in solid solution or as dispersed particles of second phase. In this work several cast alloys belonging to the cobalt-based superalloysÂ’ family were subjected to the measurement of their densities. The obtained values were thereafter analysed by considering the base chemical composition and as well as the natures and fractions of the primary carbides (CrxCy, TaC, HfC). The results show that the density variations between cobalt alloys, though rather limited, may be significant enough to have in some cases an importance in practice.