NSF Award
9761114
*** 9761114 Moyer This Small Business Innovation Research Phase I project is designed to produce high compressibility low oxide iron powder that is coated with chromium in concentration sufficient to yield ferritic stainless steel once the chromium is diffused into the iron by high temperature sintering. Chromium will be deposited on high purity water atomized iron powder by injecting chromium-containing solution of sufficient concentration to permit deposition of a chromium coating on iron powder in a fluidized bed. Presently, the proposer fabricates stainless steel parts from prealloyed stainless steel powder that is limited in compressibility. Since particle surfaces are highly oxidized, they are difficult to reduce, limiting sinterability and corrosion resistance. Elemental admixtures of 10 micron chromium powder with water atomized powder alleviate low compressibility and poor corrosion resistance, but a low oxygen 10 micron chromium powder is difficult to produce commercially. If coated chromium powder is produced, denser parts can be produced. Denser parts improve corrosion resistance, magnetic induction and tensile strength. Increased purification improves ductility and structure sensitive magnetic properties. If so, magnetic parts with improved corrosion resistance can be produced. The proposer's parts, unless forged, contain porosity. Porous parts are subject to corrosion. Increasing porosity lowers density. Coated iron powder permits production of parts that are purer and higher in density. Therefore, corrosion, magnetic and high temperature properties should be enhanced. If the process prove successful, the proposer would consider construction or expansion of a plant to produce the powder in commercial quantities. ***
