Oxidation resistant porous abradable seal member for high temperature service

Claim 1

Method of rendering a porous, abradable, sintered metal structure comprising a base alloy of chromium with nickel or cobalt sufficiently oxidation resistant to be used at temperatures up to about 1050° C. without substantial loss of strength, porosity or abradability which comprises immersing said porous sintered metal structure briefly in a suspension in an anhydrous organic fluid of at least one powdered intermetallic compound of aluminum and an element selected from the group consisting of chromium, titanium, cobalt and nickel, the particles of said intermetallic compound powder being substantially smaller than the average pore size of said porous sintered metal structure, drying said porous sintered metal after removal from said slurry, repeating said steps of immersion and drying as often as necessary until the desired weight percent of intermetallic compound has been added to said porous sintered metal structure and then heating said porous sintered metal structure at a sufficiently elevated temperature and for a sufficient time to form a structural alloy of aluminum and chromium with at least one metal selected from the group consisting of nickel, cobalt and titanium, which structure alloy is substantially all beta and gamma phases.