Iron filings

Under a metal powder is defined as a fine powder of a metal that burns usually very good, while a solid piece of metal can be difficult or impossible to burn. Metal powders are normally (mechanical) obtained by grinding. However, they can be obtained electrolytically and chemically, physically, or. By the decomposition of metal carbonyls in the metal and carbon monoxide and very pure fine metal powder can be obtained. Carbonyl is recovered from the decomposition of iron pentacarbonyl. As nickel and manganese powder may be prepared.

Examples of common metal powders:

• Magnesium ( burns with a white flame)
• Aluminum
• Zinc
• Iron
• Lead ( inflamed even by itself)

Production

The production of metal powders can be broken down as follows:

• Mechanical methods ( grinding in a mill or atomizing a molten metal )
• Physical methods ( evaporation of the metal and then condensing, sputtering of the metal in an electric arc )
• Chemical method ( reduction method, carbonyl process )
• Electrolytic processes (in an electrolytic bath, the metal is deposited as a powder at the cathode )

Use

Metal powders are, inter alia, in the manufacture of metal -ceramics used (powder metallurgy). Here they serve as the base material and are brought in by pressing the desired workpiece shape. During subsequent firing (sintering ) of the so-called green body, the molded part is solidified by diffusion processes at the contact points of the metal powders. Another method is selective laser sintering (Selective Laser Sintering), a rapid prototyping process for the rapid production of models from CAD data, it finds the sintering process directly in the powder bed instead.

• Metallurgy