Zeeland
Sinter metals make parts starting with a low carbon steel with a copper nickel blend. Some of the parts that were most notable were the little thick gears. What made these gears so memorable is that the dies made to press the shape of the gears never needed to be replaced or even repaired. The metal powder was in a 5000 pound container. The powder was a super-fine taulk. The powder is mixed according to a shop unique formula called a recipe. We were able to take parts that appeared to be solid metal and broke them into small pieces.
The first thing that we looked at was the quality lab. I thought that the lab was to small for the analysis that were accomplished on the parts. The tests that were done were:
carbon potential
press ring and bars
impact tests
tensile / compression tests
Problems that occur in sintering is that the parts spring out of shape after they leave the die. The spring out results in some out of round conditions that have to be dealt with. The amount of the density changes have to do with density changes of the powder.
To check for small cracks in some of the parts are checked by utilizing a magnaflux. Magnaflux is a water based fluorescent magnetic liquid.
The method used to impregnate the metal with copper was easier than I imagined. A piece of copper was strategically sat on the top of the part to be impregnated and when the part was heated the copper would go into the part.
There was a non-carbon furnace that was used for the iron parts only.
This tour was short but showed us how sintering was accomplished.