SINTER METALS TOUR

Sinter Metals manufactures automotive, computer, lawn and garden and many more components using powder metallurgy. They make a lot of different size gears, which range from about 1" in diameter, to 10". They pride themselves in using powder metallurgy to make parts that other powder metallurgy manufacturers will not attempt to produce. In other words, they are very confident in their manufacturing capabilities.

The presses that Sinter Metals uses range from 50 to 1000 ton in size. The larger the part, the greater amount of force that is required to manufacture the part. Our tour gave me a better understanding of powder metallurgy. It was good to be able to see a press producing parts up and close. A feeder mechanism fills the die cavity with powder, and then wipes the top of the cavity, so that the powder is level with the top surface. The punch is then driven into the die by the press, and the part is formed by the compressed metal powder. I was amazed that the parts did not just fall apart, because it looked as though it took only a little effort to compress the powder. Although the parts are still very brittle at this stage, they easily stay together.

The sintering process involves heating the parts to a temperature that is just below the melting point of the metal. This temperature is enough to bond the material more permanently, and therefore it greatly strengthens the part. Sinter Metals uses long conveyor type ovens, which sinters the parts.

One especially interesting aspect of the sintering as we were able to see, is that metals such as nickel and copper can be impregnated into the powder formed steel during the sintering process. In the oven, the nickel or copper will melt, which allows them to flow into the steel. These added metals can improve the wear of the parts which are being manufactured. When we are talking about gears, this wear resistant property is critical. Therefore, it can be easily be understood that powder metallurgy is a very good way to make gears. The powder can easily be formed into a complex shape, and then additional metals can be impregnated into the gear which enhance it's properties.