Other Powder Applications

Although REP and PREP are ideally suited to the production of clean powders for subsequent consolidation to fully dense parts, there are other applications for spherical metal particles. Wide application has been found for low-carbon steel powder in photocopier and printer applications, where rotating electrode processed spherical powder acts as a carrier for carbon black used in the printing cycle. In this application, the required particle size distribution is narrow enough so that the ability to optimize yields in the desired size range has made REP an attractive method for powder generation.

Because of their excellent flow characteristics, REP titanium, nickel-base, and high-alloy powder are being used in laser welding, repair, and enhancement of aircraft turbine parts. The same alloy powders are also being employed in the development of new free-form fabrication techniques (see the section "Laser-Based Direct Fabrication" in the article "Powder Metallurgy Methods for Rapid Prototyping" in this Volume).

Coarse particles in narrow size ranges meet unique medical needs. Cobalt-chromium alloys and titanium alloys are vacuum sintered or plasma sprayed onto the stems of prosthetic devices to form porous coatings. The porous structures so generated promote part fixation by bone ingrowth. In addition, the finer size ranges are used for consolidation to near-net shape for various implanted prostheses.

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