Laser Surface Treatment

The laser has some unique properties for surface heating. The electromagnetic radiation of a laser beam is absorbed within the first few atomic layers for opaque materials, such as metals, and there are no associated hot gas jets, eddy currents or even radiation spillage outside the optically defined beam area. In fact the applied energy can be placed precisely on the surface only where it is needed. Thus it is a true surface heater and a unique tool for surface engineering. The range of possible processes with the laser is illustrated in Figure 6.1. Common advantages of laser surfacing compared to alternative processes are: chemical cleanliness;controlled thermal penetration and therefore distortion;controlled thermal profile and therefore shape and location of heat affected region;less after machining, if any, is required;remote non-contact processing is usually possible;relatively easy to automate.