High aspect ratio welding with a high brightness laser

Experiments using high average power (HAP) diode-pumped solid state(DPSS) lasers, reveal weld cross sections that appear more like electron beam welds than traditional kilowatt class CO2 or fiber-delivered, lamp-pumped Nd:YAG welds. Because of the high beam quality, very large F# optics are possible while maintaining the required spot size needed to surpass the 1,000,000 watts/cm(2) key-holing threshold. Bead-on-plate experiments were conducted on 20mm and 40mm structural steel plates with a TRW HAP laser to determine the penetration capabilities of this new generation laser. Since the resultant welds were very narrow (0.5mm) and deep, a method of weaving was implemented to widen the fusion zone. With only 1800 watts delivered to the workplace, the cross sections of these weave welds revealed over 30mm of penetration with very parallel sidewalls adn extremely low angular distortion.