A method for manufacturing a rotary regenerator seal cross arm assembly

摘要

A method for manufacturing a regenerator cross arm seal assembly uniformly stressing a cross arm substrate member 36 to a flattened condition; fixedly securing the substrate member 36 to a holding fixture to maintain it flat between the opposite ends at the top surface 72 of the substrate member, bond coating the top surface 72 to form an oxidation resistant surface 74 thereon, plasma spray coating a layer 78 of nickel oxide on the bond coating to prevent contamination thereof by subsequently applied wear surface material, plasma spray depositing a nickel oxide/calcium fluoride wear coating 82 to a uniform depth across the plasma spray coating of nickel oxide for defining a wear surface of concave form; double coating the substrate member 36 by applying a like coating to the back side surface 88 of the substrate and thereafter heat treating the coated substrate member to produce a thermally induced growth stress in the wear surface coating and back side coating that substantially equalizes the prestress in the substrate member thereby to produce a resultant flat wear surface on the cross arm assembly when the substrate member is placed in a gas turbine engine regenerator and operated under temperature conditions in the order of 1400 DEG F (760 DEG C). IMAGE