Titanium (alloy) parts - with aluminium diffused into surface, for wear-, oxidation-,corrosion and erosion-resistance

摘要

Ti (alloy) parts, which must have hard, wear-, oxidn.-, corrosion- and erosion-resistant surface besides high strength to density ratio, have Al diffused into the surface. The protective layer is 25 - 100 mu m thick and is produced by gas phase diffusion, by packing the part in a powder mixt. of 5 - 30 wt.% Al, 0.1 - 1.5% halode (CrCl3), rest inert filler (Al2O3) and subjecting to diffusion treatment for 3 - 15 hr. at 750 - 1000 degrees C under a protective (inert) gas. The treatment is esp. useful for compressor discs and blades for aircraft engines, crank- and cam-shafts, piston rods and gudgeon pins in automobile construction and for pump-impeller blades, bearings and valves in chemical plant.