Microwire Feeder for Laser Applications

This paper focuses on the design and development of a fine microwire feeder for laser applications. The use of metallic wires as a medium of deposition has been popular in aerospace and car manufacturing industries. These micro sized wires are also gaining importance in medical and semi-conductor industries. The use of wire-feeders in laser welding and electrical discharge machining applications has been prominent. There are devices used in laser applications which can handle wires from 0.25mm to 10.0 mm in diameter. The handling of microsized wire in laser application is often considered difficult due to its low buckling strength exposure to harsh environment. The primary function of the microwire feeder described in this paper was to feed wires of varying microdiameters to a desired location with high accuracy and precision to be used in a laser aided manufacturing processes. This can be designed by dividing the microwire feeder into four basic sub-mechanisms: (1) feeding mechanism (2) transfer mechanism (3) precision guidance mechanism (4) adjustment mechanism. These sub-mechanisms are integrated to account for compactness, flexibility and precision. This microwire feeder is capable of handling wires as low as 0.05 mm in diameter. The precision and accuracy of the device was experimentally tested prior to its practical application. A case study on laser deposition was presented; where; a 316 stainless steel microwire of 0.125 mm diameter was fed into a melt pool of 0.2 mm. The wire feed and the traverse speed of the table were varied to achieve a uniformly distributed clad. The effect of wire feed and traverse speed were studied and a deposition process window was developed for future experimentation.