Rapid solidification processing

Virtually every reference at the end of this chapter is to post-war publications, and the majority are to papers published during the past 15 years. This shows, clearly enough, that extreme materials are recent features of materials science and engineering (MSE), and there is every indication that the focus on materials of the kind discussed in this chapter will continue to develop. Individual approaches come and go - thus, rapid solidification processing, the oldest of the approaches discussed here, seems to have passed its apogee - while others go from strength to strength ... 

Das, Chang, Raybould High Performance Magnesium Alloys by Rapid Solidification Processing , Light Metal Age, Dec. 5-8 1986... 

Staff "Rapid-Solidification Processing Improves Metal-MaLrix Composites Advanced Materials c Processes. 71 (November 199(1). 

Rare earth addition and rapid solidification processing might result in (i) grain refinement and (ii) development of fine incoherent dispersoids leading to dispersed slip. Addition of dispersoids such as Er203 and Ce2S3 to Ti3Al(Nb) alloys produces refinement... 

Amorphons Al alloys have been prepared by rapid solidification processing (RSP, see 6.) nanosfmcfmal alloys prepared from fhese glasses have potential applications as high-sfrengfh, low-densify alloys. ... 

Rapid solidification processing (RSP), for example, by melt spinning onto a cooled copper drum, which is capable of retaining many alloys in a glassy (amorphous) state or in nanocrystalline form ... 

Rapid solidification process extends solubility limits, often resulting in novel phases... 

Rapid solidification processes are successfully used for A1 alloys to form a dispersion particles of intermetallic phases, which resist coarsening and strengthen the alloys at elevated temperatures. It has recently been shown that metastable intermetallic phases with a quasicrystalline structure, mainly of the icosahedral type, can also be produced by rapid solidification [23], As distinct from a crystalline state, translational long-range order is absent in quasicrystals, but there is rotational symmetry with 5-, 8-, 10- or 12-fold axes, which is forbidden in crystalline materials. The absence of translational symmetry in all three orthogonal directions is characteristic of the icosahedral structure [24],... 

Advances in electrochemical systems rest in large measure with the evolution of new materials that exhibit chemical stability in severe environments, high electrocatalytic activity, rapid ion conductivity, etc. Examples include RuOx-TiOy-Ti electrocatalysts, the polymer Nafion, yttrium-stabilized zirconate and beta-alumina electrolytes, and metastable alloys produced by rapid solidification processing. 

We conclude that the cooling velocity in the rapid solidification process has a strong relationship with the reaction velocity and/or the velocity of the movement of solidification fronts, which decides the stable phase under the given conditions. More attention, therefore, should be paid to the reaction velocity of phase formation for controlling the microstructures of the rare-earth permanent magnets. 

Continuous glassy metal ribbons can be formed with high quench rates from their inviscid melts by a rapid solidification process [60] that is akin to a generic bushing process (Figure 3, top left), except that the extruded ribbon must be rapidly cooled on the surface of a cold quench wheel. Continuous aluminate glass fibers and metal wires [10-12] and continuous amorphous YAG fibers [73] can be melt spun from inviscid melts by increasing the jet lifetime... 

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