Keltool

From: Yakov Horenstein (yakov@planet.it)
Date: Wed Nov 06 1996 - 17:29:57 EET


Someone asked about Keltool. Here are excerpts from an article last year
which describes it.

>Keltool, a metal-sintering technology
>invented by 3M Co. to rapidly and economically
>create tools for small metal parts (no larger than 6 inches) that could be
>reproduced in quantities from several hundred to millions.
>
>An .STL master is used to make long-life production
>tooling from Stellite, A-6 tool steel, and a composite material of A-6 tool
>steel, tungsten carbide, and a copper alloy. In the composite material, the
>dispersion of tungsten carbide enhances wear resistance, while copper
>improves thermal conductivity by about 30 percent.
>
>In the Keltool process, a stereolithography part designed by a tool and mold
>specialist is made as a negative of the final shape. The negative pattern is
>placed in a box filled with RTV rubber, which cures and hardens. Ultrafine
>metal powder (Stellite, A-6 tool steel particles) is then poured into the
>rubber positive. The powder has some thermoplastic binder in it, as well as
>a varied size distribution (from 0.5 to 20 microns) for tight packing and
>high fill ratio. The molded powder form is heated in a low-temperature oven
>(100 C) to create a green part. The green part is then demolded and fired in
>a furnace at 1300 C, which burns out the binder and sinters the part
>together. The sintered parts can then be infiltrated with copper to produce
>a tool. The resulting small parts have dimensional accuracy to 0.001 inch
>per linear inch.

----------------------------------------------------
Yakov Horenstein Tel: +39 2 65 35 12
Milano, Italy Fax: +39 2 2900 6208



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