Aluminum and Magnesium Cores

It would be desirable to manufacture lightweight articles from particles made from aluminum or magnesium or their alloys using the 3D-printing rapid prototyping technique (19). 

However, in the past it has not been possible to do so owing to the reactivity of A1 and Mg particles and their propensity to readily oxidize in air to form an oxide skin on the particle s surface that impedes sintering/welding of the particles to each other. 

Coated particles were developed that are composed of a core metal selected from Al, Mg and their alloys, respectively, and a coating that protects the core from oxidation. 

The coating is a metal whose oxide is reducible by heating in a non-oxidizing atmosphere. For example, the coating metal is selected from copper, nickel, zinc, or tin. Copper is the most preferred coating metal. 

Either only one layer or several layers of copper are used. For example, a copper topcoat is imderlaid with a first undercoating such as Zn or Si that can form an alloy with the copper and the core metal. The coating alloy melts below the liquidus temperature of the Al or Mg core metal. Further, for aluminum particles, the undercoat preferably comprises Zn, Si, or Mg. 

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Advantages of silicon x-radiation include the access of aluminum and magnesium core level (Is) lines and the corresponding (KLL) Auger transitions for chemical state identification and improved quantitation, because these lines are at least 10 times more intense than the corresponding (2p) or (2s) lines. The construction of an off-axis reactor has produced a simple, versatile and inexpensive system easily adapted to any vacuum system. The role of AES and SAM in catalyst research will also be highlighted by examples. 

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