Polymer Castings take on metals

To build equipment such as lathes, milling-machines, coordinate-measuring machines, and pump-bases, the preferred material has been cast-iron or steel. In a process that typically takes four-months, the iron is cast, annealed, precision machined, annealed again, and finally painted. This article discusses a polymer-composite that can be cast within days at 30% of the cost of cast-iron. Also, since the composites can be cast in color, they do not need to be painted. The composites are formed with a mixture of reactive, high-strength resin and aggregates. Because the composites are precisely graded, air voids are removed which results in stronger castings. The aggregates can be anything with a high-hardness coefficient such as quartz, basalt, granite, or even recycled glass. Each aggregate has its own strengths and weaknesses so choosing an appropriate one to meet the needs of the final product is important. For the resin, the most popular choice is epoxy due to its chemical resistance, long-term stability, and good mechanical properties. Polymer composites offer an increased flexibility mold materials because they do not have to get as hot as cast-iron. Another advantage to composites is that they dampen vibration which can reduce wear over time.  Full article in Machine Design.

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