NI BASE COATING ALLOY FOR CAST IRON SUBSTRATES AND ITS APPLICATION TO WELD-BONDED COMPOSITES SUCH AS GLASS MOULDS

摘要

A method for producing a weld-bonded nickel-base alloy coating on a cast iron part with minimum porosity at the weld interface is provided using a plasma transferred arc process in which the cast iron part is electrically coupled to the plasma-forming circuit, the flow of powder being directed into the plasma arc to the surface of the cast iron part. The method further resides in controlling the deposit of the nickel-base alloy during spraying to maintain a puddle of the alloy between the transfer arc plasma and the cast iron part substrate to protect it from overheating and burning from the transfer arc while promoting a welding reaction between the puddle and the cast iron substrate. The plasma spraying is continued progressively along the cast iron substrate to be coated while maintaining the alloy puddle between the plasma arc and the cast iron until completion of the coating thereof. The invention also relates to a composite article of manufacture.