Alternating current field assisted pack boriding to Fe 2 B coating

An alternating current field (ACF) was employed in pack boriding at 800°C to produce a thick Fe₂B coating on an AISI 1045 steel. The effect of ACF on the growth of the boride coating was studied, and the coating's structure and phases were characterised. The results showed that an ACF could greatly enhance pack boriding and lead to the formation of a single Fe₂B phase coating, which is much thicker than a coating by corresponding conventional pack boriding (CPB). The ACF's enhancing effect increased almost proportionally with increasing ACF currents from 1 to 9 A. The growth rate of the coating versus boriding time showed the same parabolic character as CPB. The mechanism of the ACF's effect on the formation of the single phase Fe₂B coating was associated with enhanced chemical reactions in the boriding media and enhanced diffusion both in the media and in the treated sample.