| Popis: |
In this chapter, nickel-based powder production by the decomposition of nickel carbonyl, by the reduction of the aqueous solution of a nickel salt with hydrogen under pressure (the Sherritt process), by inert gas or water atomization, by mechanical alloying, by the electrolytic method, and by solid-phase reduction is discussed. Gas atomization reaction synthesis (GARS) used for the production of precursor powders for oxide dispersion strengthening (ODS) nickel alloy is described. Nickel-base superalloys alloyed by refractory elements and produced by gas atomization, centrifugal atomization, mechanical alloying, and the plasma rotating electrode process are characterized. Turbine airfoil architectures that include Ni-based superalloys coated with β-NiAl aluminide diffusion bond coat systems and supplied by near surface embedded cooling microchannels within an ODS layer are considered. Hardfacing consumable materials acceptable in different forms, such as powder, solid welding rods or wires, and tubular rods or wires are characterized. Various means of producing nickel and nickel-alloy powders by electrolytic processes are described. The safety aspects of health and environmental protection measures in carbonyl powder production are considered. Application fields, including carbonyl powders, hydrometallurgical processing powders, hardfacing powders, superalloy powders, electrolytic powders, and reduction processing powders are characterized. |
