Vertical laser cladding system

摘要

A vertical laser cladding system is particularly effective for the interior surfaces of tube-like structures. The vertical cladding process works from bottom to top, so that previously clad layers form a shelf for subsequent application of cladding powder. This system is also particularly effective for handling double-bore plasticating barrels.

主权项

1. A method of cladding an interior surface of a tube constituted as a first metallic material, using a laser welding head having a nozzle to apply a second metallic material constituted as a loose powder with carbide particles to the interior surface, said method comprising the steps of:
a) preheating the tube before cladding; b) aligning the tube in a substantially vertical position; c) placing the laser welding head within the tube in a manner that permits rotation between the tube and the laser welding head; d) initiating rotation between the tube and the laser welding head; e) irradiating the interior surface of the tube with the laser welding head and placing the loose powder with carbide particles into the tube to form a weld bead of said second metallic material at the interior surface of the tube, said weld bead having an upper clad shelf surface extending outward from the interior surface of the tube; f) moving the laser welding head upwards to stay above the weld bead; g) placing the loose powder with carbide particles onto the upper clad shelf surface of a previously irradiated, existing clad portion of the weld bead by dispensing through said nozzle; h) continuing rotation between the tube and said laser welding head to expand the weld bead around the interior surface of the tube by forming newly irradiated clad portions to extend from previously irradiated, existing clad portions while irradiating from above the weld bead; i) repeating steps (f) through (h) until the interior surface of the tube is clad with the second metallic material; and, j) cooling over a predetermined amount of time after cladding the second metallic material to the interior surface to said tube to prevent cracking of the cladded second metallic material.