In this article we are going to talk about TDC. We’ll discuss what it stands for, the hardness and how useful it is.
Thin dense chromium coatings is a proprietary, very hard (78Rc) very hard chromium. XADC coating uses the thin dense chromium solution as it’s base but is infused with a synthetic diamond particulate, which is responsible for the extreme hardness quotient. Both coatings, at a microscopic level, provide a nodular (as opposed to flat) finish.
These coatings thickness is a standard deposit of.0001/.0003″ per surface. However, in molding, the .000050/.0002″ range is more realistic, giving the tight tolerances that are the industry standards. And unlike other typical hard chrome a thinner deposit of thin dense chromium, there is a thinner deposit of TDC that will not inhibit the coatings’ efficacy, and may prevent excessive edge build up.
RMS finishes will improve slightly to . Surfaces greater than will reflect greatly improved finishes. Both internal and external surfaces on all part configurations can be uniformly processed. As the finishing step for machine parts and manufacturing components, It imparts a satiny, silver matte, micronodular finish. It also withstands temperatures of -400º F to 1600º F (-240º C to 871º C). With the surface hardness of 78Rc, and vickers diamond -1360/1400.
As the surface hardness and surface finish of the basis metals improve, the performance of the TDC coating also improves. In order to maximize the thin dense chromium coating performance, components should be engineered to a minimum of 50Rc, 40 pt. carbon steel with a minimum surface finish of.
The thin dense chromium coating process control prevents the embrittlement phenomenon from occurring,though original manufacturing conditions may not, necessarily, be removable. The process also will not affect the tensile, yield or fatigue properties of the basis metal. Pre- and post-baking are available upon request or specification. The TDC coating also certifies to AMS-2438, AMS QQ-C-320, AMS-2406, and most other military/industrial specifications.
TDC also resists attack by most organic and inorganic compounds, with the exception of sulfuric acid and hydrochloric acid. Inferior metal surface finish and low part hardness may inhibit thin dense chromium coatings corrosion resistant properties. It also has the approved for use of the FDA/USDA, without concern on food processing equipment, in clean room environments and in medical/pharmaceutical applications. Independent testing has proven no issue of toxicity or skin irritation in thin dense chromium coated parts.