| 摘要 |
<p>The manufacture is of a piston (20) of aluminium or aluminium alloy for an internal combustion engine. The piston ring grooves (21) of such pistons tend to be worn by the associated piston rings. Before a piston ring groove is machined on the piston an alloying material is applied to the piston and treated by an electron beam or laser beam to form an alloyed region extending around the piston. The alloy in the region is more wear resistant than the material of the piston. A piston ring groove is then machined in the alloyed region to provide a groove with side walls of wear-resistant alloy.</p> |
