Protective Coatings for the Heat Treatment of Special Alloys: Details of the Berkatekt Coatings Which Were Developed By Rolls‐Royce Ltd.

MANY of the creep‐resistant and heat resistant metals used in the aircraft industry, such as the nickel‐based alloys, titanium and its alloys, stainless steels and high temperature alloy steels must be subjected to heat treatment to relieve stresses. This is necessary because, when stretched, pressed or manipulated, such materials work, harden. In the process of heat treatment, formidable problems of oxidation and scale formation are encountered which demand lengthy descaling operations after treatment, or the use of controlled‐atmosphcrc or vacuum furnaces for oxidation‐susceptible metals like titanium. Within the last two years, however, development work by Rolls‐Royce Ltd. has produced some very effective new protective coatings, which, as a result of subsequent co‐operation with F. W. Berk and Co. Ltd., have now been made generally available under the name of ‘Berkatekt’ coatings. coatings are licensed for use under Patents applied for by Rolls‐Royce Ltd.