| 摘要 |
Poppet valves are manufactured by rotating a metal spray deposition nozzle relative to a rod or tube about the longitudinal axis of the rod or tube to deposit metal at a localized region intermediate the ends of the rod or tube so as to form a flange-like accretion on the rod or tube, and subsequently cutting through the rod or tube and the accretion at the centre of the localized region to form two poppet valve preforms which are then subjected to finishing treatments. Metals having differing properties of heat, wear and corrosion resistance may be coated upon one another in forming said accretion. |
