Armoloy® and XADC-Armoloy® Frequently Asked Questions What are Armoloy TDC and XADC-Armoloy coatings? Armoloy TDC (thin dense chrome) is a proprietary, very hard (78Rc), very dense chromium. XADC-Armoloy (98 Rc) uses the Armoloy TDC solution as its 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 How thick are the coatings? Standard deposit thickness is .0001/.0003" per surface. However, in molding, the .000050/.0002" range is more realistic, given the tight tolerances that are the industry standard. Unlike traditional hard chrome, a thinner deposit of Armoloy TDC or XADC-Armoloy does not inhibit the coatings' efficacy, and may prevent excessive edge build. How are the coatings applied? The coatings are applied electrolytically, following the general principles of electroplating, but employing proprietary chemistry and proprietary fixturing methods/materials. The process is known as "cool": parts will see temperatures no higher than 160F. Lower temperatures mean no risk of heat-induced damage (annealing, distortion, warping). Due to proprietary prep procedures, the coatings bond mechanically and absolutely adhere to the surface of the substrate. Why coat? The Armoloy coatings serve three main purposes: 1. Wear/abrasion resistance (due to surface hardness). 2. Lubricity/release/friction reduction (due to nodular finish). 3. Corrosion resistance (on tool steel, comparable to 440C stainless steel; chromium is a natural corrosion resistant).   What types of materials can be coated? Nearly all ferrous and non-ferrous metals can be coated, including common molding steels such as H-13, S-7, P-20, 420SS, A-2, D-2, and copper alloys such as Moldmax and Ampcoloy. Titanium, zinc, and magnesium are not recommended for Armoloy coating. Is the hardness of the substrate an issue? Generally, the harder the base metal, the more effective the Armoloy TDC and XADC-Armoloy coatings. Common Rc hardness for tool steels to be coated is 45-55 Rc. Armoloy can also coat gas or ion nitrided surfaces, though it is important to indicate that this process has occurred before the coating process begins. In the case of copper alloys, where hardness cannot be dramatically improved, the coatings still can provide protection against abrasive wear, without inhibiting the copper's thermal diffusion properties. What about textured surfaces and gloss levels? The Armoloy coatings, due to their thinness, will not "fill in" a textured surface; they will evenly coat the texture to which they are applied. They will as well impart increased wear resistance to that textured surface, allowing the tool to perform longer and more efficiently without expensive re-texturing. Gloss levels, from matte to high-gloss, are strictly maintained by Armoloy of Texas throughout the coating cycle. It is always helpful to send Armoloy a formed plastic part from the component whose gloss level is at issue, to use as a benchmark for the desired gloss level. Can tools of different types/dimensions be coated in the same lot? Yes. Armoloy fixtures each tool separately according to its design. It is not a "batch" or "barrel" process. Armoloy would likely issue a "processing charge" that would cover the entire lot, including the various set-ups/tooling requirements necessary to accommodate the different part geometries involved. What temperatures can the coatings withstand? Both Armoloy TDC and XADC-Armoloy will withstand temperatures from -400F to 1600F Hard chrome and electroless nickel are prone to chipping and flaking; is this the case with the Armoloy coatings? Absolutely not. Armoloy guarantees an absolute bond with the substrate, one that will not crack, chip, flake or peel under normal molding conditions Can the coating be stripped? What if a repair/design change is necessary? Armoloy can and does strip and reapply its own coatings, via a proprietary, mild, non-acidic bath. Armoloy will selectively strip the coatings of its competitors, but requires as much information as possible to do so, including type of coating, coating thickness, and the base metal on which the coating is applied. Parts that have been stripped/recoated many times, that have been welded, that suffer from metal fatigue, or that have not been properly stress-relieved may incur adverse effects from the stripping process. It is always in your best interest to provide Armoloy with as much information as possible in regard to stripping. An Armoloy TDC or XADC-Armoloy coated part may be repaired/machined/welded while coated. In the case of welding, the coating will vaporize at the point of the weld, leaving the balance of the coated surfaces intact and functional. When machining a coated surface, and especially in the case of XADC-Armoloy, keep in mind that the first .0001/.0003" of the machinable surface is 78/98 Rc. When machining a coated surface, flood that surface with coolant and take very thin cuts. Can an Armoloy TDC or XADC-Armoloy coated surface be polished? Yes. It is essential, to achieve a desired surface finish after coating, that the part be finished to that degree before coating. Both coatings can be diamond-polished back to an SPE #2 (mirror finish) after coating only if this same finish appears on the part before coating.       ^back to top