Hardening and reconditioning machine components by electromagnetic coating

Abstract

Electromagnetic coating (EMC) is one of the progressive methods concerned with the preparation of a piece surface layer with specific physical and mechanical properties. It is accomplished with the aid of an electromagnetic head mounted, for instance, on a lathe that provides rotation and displacement of a hardened surface relative to a pole piece. As a source of discharge unipolar pulse current, use is made of welding transformers with a single-half-period rectification circuit. EMC optimal conditions for processing cylindrical coatings are as follows: operating current, 120 A; magnetic induction in a working gap, 0-7 T; the working gap, 1-5 mm; rotation speed, 15r.p.m.; ferropowder feed rate, 20-25gmin⁻¹. Under these conditions the coating thickness is 0-7 mm and the hardened transition layer thickness is 0-9 mm.