The Influence of the Working Conditions of the Electrospark Granules Deposition on the Formation of Cracks in Ti-Al Intermetallic Coatings

Abstract

Electrospark treatment of a titanium alloy Ti6Al4V in a mixture of granules allows the formation of intermetallic Ti-Al coatings. The coating structure is penetrated by a network of cracks with a thickness of 0.46 to 1.19 microns and a specific area of 1.5 to 3.4%. A change in the ratio of Ti to Al in the mixture of granules does not lead to a monotonic change in the thickness and number of cracks. A decrease in the pulse duration from 200 to 20 μs leads to a slight decrease in the thickness of cracks and significantly increases their total area from 2.1 to 3.4%. An increase in the discharge pulse repetition rate can significantly increase the thickness of cracks in Ti-Al electrospark coatings.