- Mechanical alloying
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Mechanical alloying (MA) is a solid-state powder processing technique involving repeated cold welding, fracturing, and re-welding of powder particles in a high-energy ball mill. Originally developed to produce oxide-dispersion strengthened (ODS) nickel- and iron-base superalloys for applications in the aerospace industry[1], MA has now been shown to be capable of synthesizing a variety of equilibrium and non-equilibrium alloy phases starting from blended elemental or pre-alloyed powders.[2]
Mechanical alloying is a process much like metal powder processing where metals may be mixed producing super alloys. Mechanical alloying is essentially two steps, one being the ball mill where the materials to be alloyed are combined and ground to a fine powder substance. The second step consists of sintering and later applying hot isostatic pressure (HIP) to final fuse the elements together, the HIP process heats the metal above its re-crystallization temperature (0.6 Melting temperature). The combination of such efforts produces an alloy suitable for high heat turbine blades and aerospace components.
The final heat treatment stage helps remove existing internal stress concentrations produced during any cold compaction which may have been used. By using HIP the material reaches re-crystallization where grain size and state may be controlled under cooling.
References
External Links
Mechanical alloying, comprehensive information from University of Cambridge.
Categories:- Metallurgical processes
- Materials stubs
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