Diffusion brazing of stainless steel or superalloys - using interfacial diffusion layer of tin, indium, antimony, gallium or germanium

摘要

Pieces of stainless steel or superalloy are bonded by (a) providing a layer of >=1 Sn, In, Sb, Ga or Ge between the bonding faces and (b) heat treating in a controlled atmos. at >900 degrees C but below the solidus temp. of the pieces to diffuse the layer into the pieces to form a cpd. or solid soln. a moderate pressure being applied during at least part of the heat treatment to maintain the pieces in posn. and to promote diffusion while avoiding deformation. Method is esp. useful for bonding abradable refractory metal coatings to turbine housings. The interface layer is cheaper and easier to use than prior art layers and reduction in high temp. ductility of the workpieces.