Thermal Spray Alternatives for Electroplated Chromium

Abstract

Abstract Many thermal spray coatings provide excellent wear and corrosion resistance, while providing die same surface finish offered by chromium plating. In the past, the choice between thermal spraying or plating was usually based on part size, area to be coated, cost and familiarity with one or the other method. Today, the thermal spray processes are showing greater popularity due to: ♦ New thermal spray processes and coatings with better properties ♦ Increased chromium plating costs due to stricter regulations on the process and the disposal of its waste products ♦ The closing of chromium plating facilities Thermal spraying offers an opportunity to select a coating from a wide variety of processes and materials that will meet the specific requirements of each application. While this may cause some difficulty in selecting the optimum coating, the selected thermal spray coating often has superior propolies and/or lower cost compared to chromium plating. The highest quality coatings are sprayed by the HVOF process, many with carbide containing materials. Dense plasma grayed ceramic materials offer good wear resistance plus elevated temperature capability. The most economical replacements for chromium plate are applied by the two-wire arc spray process. This paper examines the properties and costs of eight different dismal sprayed coatings and compares them with electroplated chromium.