PISTON MANUFACTURE

摘要

An apparatus (10, 60) for use in manufacturing pistons is operable to modify a portion of the material of a piston blank (12) so that said portion of material has different properties to the remainder of said blank. This is achieved by plasticising the material using material modifying means (20) of the apparatus by which a tool (32) is rotated within the blank to generate frictional heat. The apparatus also comprises tool heating means (42) operable to heat a tool (32) mounted on a mounting (30) of the material modifying means (20).