| 摘要 |
A compressor wheel for a turbocharger comprises a central hub 24 and a plurality of impeller blades 25 extending outwardly from the hub, each of the blades defining a leading edge 27, a trailing edge 28 and a root portion 26 which connects the blade to the hub, wherein at least one of the blades has a plastically deformed surface, eg its suction surface, provided with a surface layer of a ceramic material. The plastic deformation, to induce residual compressive stresses at the surface of the blades, may be achieved by shot peening or laser peening. The ceramic layer may comprise an oxide of a material, eg aluminium, from which the blade is made and may be formed by eg anodising or plasma electrolytic oxidation (PEO). Any microscopic pores remaining may be filled with a sealant, eg a fluoropolymer, sol-gel or silicate. |
