Diffusion coating of metals

Abstract

Abstract IN PACK IMPREGNATION OR CEMENTATION PROCESSES FOR THE DIFFUSION COATING OF ONE OR MORE METALS INTO THE SURFACE OF METAL ARTICLES, IMPROVED TECHNIQUES AND COMPOSITIONS ARE PROVIDED FOR THE DIFFUSION COATING F METALS SUCH AS ALLUMINUM AND ANTIMONY INTO THE SURFACE OF A VARIETY OF FERROUS AND OTHER METAL ARTICLES EMBEDDED IN A POWDERED COATING PACK AT COATING TEMPERATURES CONSIDERABLY LOWER (BY AS MUCH AS 200*F.) THAN THOSE TEMPERATURES REQUIRED BY CONVENTIONAL TECHNIQUES TO PROVIDE EFFECTIVE DIFFUSION COATING OF THE SAME MATERIALS. THIS IS ACCOMPLISHED BY PROVIDING IN THE COATING PACK AN ACCELERATING COMPONENT (SUCH AS EITHER RELATIVELY VOLATILE METALS AS CADMIUM, LEAD, ZINC, ETC., OR CERTAIN LONG CHAIN ORGANIC COMPOUNDS) WHICH DO NOT ULTIMATELY FORM A SUBSTANTIAL OR SIGNIFICANT PART OF THE DIFFUSION COATING, BUT DO ACT IN THE COATING PACK TO ACCELERATE THE DIFFUSION OF THE COATING METALS INTO THE ARTICLES BEING COATED AT LOWER TEMPERATURES TO ACHIEVE INCREASED COATING DEPOSITION AT TEMPERATURES LOWER THAN OTHERWISE OBTAINABLE, AND PERMITTING SATISFACTORY COATINGS AT TEMPERATURES BELOW THOSE AT WHICH AT WHICH SOME UNDESIRED CRYSTALLOGRAPHIC OR METALLOGRAPHIC OR PHYSICAL PROPERTY CHANGE WOULD OCCUR IN THE METAL ARTICLES BEING COATED.

Inventors

• 👤 Harry Brill-Edwards
• 👤 Kenneth K Speirs

Bibliographic Details