Coatings – Overview and Comments on Properties
IVAC offers a variety of hard, wear resistant tool coatings with low friction coefficients. The hardness improves wear resistance, which extends tool life. The low friction reduces the heat generated during sliding, permits faster machining with increased productivity, and yields better surface finish. The chemical inertness of these coatings improves the oxidation resistance of coated tools, and reduces surface buildup.
The optimum temperature for our Physical Vapor Deposition (PVD) process depends on the material to be coated. For high speed steels this is 900 ºF -950 ºF (480 ºC -510 ºC), and for cobalt cemented tungsten carbide, 1100 ºF – 1300 ºF (600 ºC -700 ºC).
The thickness of our coatings is in the range of 2-5 µm (or~0.0001″-0.0002″).
Note that we do not quote physical properties for coatings! They are simply not well known! While the bulk properties of materials used as hard coatings are known, those for their thin film counterparts can be very different, and are ill-defined. These depend strongly upon the interplay of factors, such as deposition conditions, substrate material, surface preparation and morphology, the presence or absence of para-surfce impurities introduced into the substrate during manufacturing, temperature, humidity, and measurement conditions.
Also, properties derived in the laboratory are typically poor predictors of actual manufacturing performance of coated tools. Consequently, applications of a particular coating to new operations must be tested and optimized under production conditions on the shop floor.