Layered construction of in-situ metal matrix composites

A method of layer-by-layer construction of a metallic part comprising:

• supplying particles of an alloy, wherein said alloy consists of Fe at a level of 50.0 to 76.0 wt. %;
• B at 0.5 to 3.0 wt. %;
• Cr at 15.0 to 22.0 wt. %;
• Si at 2.0 to 5.0 wt. %;
• Ni at 5.0 to 15.0 wt. %;
• optionally C at 0.0 to 0.5%, optionally Mn at 0.3 to 3.0 weight %, and unavoidable impurities;
• supplying a substrate;
• applying said alloy onto said substrate by melting said particles of said alloy into a molten state and cooling to form a solidified layer of said alloy and repeating to form successive solidified layers of said alloy, wherein each of said solidified layers of said alloy has a thickness as formed of 3.0 to 200.0 microns;
• heat treating said solidified layers of said alloy in a vacuum atmosphere, an inert gas atmosphere, a reducing gas atmosphere, or an atmosphere comprising a mixture of inert and reducing gases;
• optionally removing said substrate to form a free-standing metallic part;
• and
• wherein one or more solidified layers of said alloy has an abrasion resistance as measured by ASTM G65-04(2010) Procedure A of less than or equal to 175 mm3.