Influence of Rare Earths Additions on the Microstructure and Hardness of Heat-treated Nanostructured Superalloy Inconel 718

The superalloy Inconel 718 is greatly employed in high-temperature applications due to its principal characteristics: high resistance to oxidation and excellent mechanical performance at elevated temperatures; hence, its main uses are in aeronautics and aerospace engines, nuclear power generation and petrochemical industries

Effect of Ni additions and hot deformation on precipitation behavior and hardness in AleSieMg aged alloys

Additions of 1e2 Ni (wt. %) and hot deformation on the microstructure and hardness of A356 aged alloy were studied. The results show that the addition of this element generates the formation of Ni31Si12 and NiFe phases with high thermal stability. In addition, the presence of Ni into the Al matrix and precipitates of the second phase affect the precipitation kinetics, transformation sequence, growth rate, and slow loss of hardness in the system after reaching the maximum values. For example, the Ni additions contribute to generating the coexistence of b" precipitate and GP-I zones. Of all the strengthening mechanisms present, hardening by precipitation is the most influential in the hardnes

Effect of Fe impurities and pure Cr additions on microstructure of nanostructured WC-10Co alloy sintered by HIP

The present work evaluates the effect of both, Fe impurities and Cr addition, in nanostructured WC-10Co cemented carbides, which are sintered by hot isostatic pressing. Fe impurities and Cr addition in nanostructured WC-10Co alloy generate a series of microstructural and structural changes in the morphology, present phases, crystallite size and density, which in turn influences the microhardness of the samples. Such changes are mainly related to the nature of binder, generation of a bimodal grain size distribution and an abnormal grain growth of the WC phase and the formation of the η phase