|Solidification of LaNi5-xSnx in an plasma/arc furnace|
Arc casting of intermetallics may sound mundane, however, depending on the solidification behavior of the constituents inhomogeneity, defects, and other physical phenomena may result. Below is an example of solidification segregation that generates stress in a casting.
The modified AB5 alloy is used for metal hydride hydrogen storage. Upon solidification the Sn is partially rejected and increases in concentration in the remaining liquid. Upon completing solidification there is a great deal of internal stress in the ingot. As the ingot cools further the stress is relieved.
|Atomization of liquid metal|
Atomization of metal requires high pressure gas and specialized chambers for cooling and collecting the powders without contamination. The critical step for morphological control is the impingement of the gas on the melt stream.
The first video is a color video of a liquid metal stream being atomized by high pressure gas.
The following video is a slow motion capture of an atomization event.
|Melt spinning formation of metallic ribbon|
Melt-spinning is a method used for producing amorphous ribbon, which can then be converted to powder. The quality of the ribbon is controlled by several processing factors.
This video shows the melt stream, melt pool, and ribbon formation in slow motion.