The refurbishment of ships and submarines is a major effort of the U. S. Navy. This often requires the removal of large components for welding and/or weld cladding operations. This is avery slow and costly operation that impacts the readiness of the ship and increases the lifecycle cost of the combatant. In an effort to address this problem, the Navy’s Manufacturing Technology Office (MANTECH) is funding the development of laser materials processing procedures. These processes include laser welding, cutting, and cladding by CO2 and Nd:YAG. One specific program is the development of a portable Nd:YAG laser system by Mare Island Naval Shipyard and the Applied Research Laboratory, The Pennsylvania State University (ARL Penn state) for laser materials processing on-board ships and submarines.
The system is based on a Martek Laser 1.8 kW Nd:YAG laser that is delivered to the work piece by fiber optics. The system is to be housed on a skid/frame system that allows for the systemto be moved from job site to job site for utilization (Figure 1). The optics heads have been designed to allow for use with portable machining tools, robot/tele-operator manipulators, and/or simple linear motion devices.
Processing procedures have been developed for a number of applications. These include laser cutting of ferrous and aluminum alloys at various thicknesses. Aluminum tubing 0.76 mm (0.030inches) has been cut at speed of up to 21 cm/sec (500 ipm). Laser welding has also been accomplished in a number of ferrous and nonferrous alloys. Welds in ASTM A533 steel have been made toa depth of 3.2 cm (0.125 inches). Laser cladding of Stellite 6 has been accomplished on a number of stainless and carbon steels.
Additional work is ongoing to increase the capabilities of the system. This includes the development of procedures for the cutting, welding, and cladding of out-of-position components. Also a 2.4, laser system is under development.
Preliminary results indicate that a portable laser system may have many applications in there refurbishment of Naval vessels. Such a system would decrease the lifecycle cost of many components.