Weld bead and joint strength characteristics during laser welding of 87% Al_2O_3 ceramics - High-power CO_2 laser welding of 87% Al_2O_3 ceramics (1st report)

摘要

To develop a joining technology for thick ceramics, the fundamental characteristics of high-power CO_2 laser welding of 87% Al_2O_3 ceramics have been investigated. The results suggest that a penetration depth of 20 mm is possible at a welding speed of 6.5 mm/sec and laser power of 10 kW. The porosity ratio is lower at lower input powers, also tending to decrease with a decreasing welding speed at the same input power. The bending strength decreases with an increasing porosity ratio. Porosities, especially large sink mark porosities at th,e bead centre, strongly affect the bending strength of welded joints in alumina ceramics. The root bending strength of 4 mm thick butt-welded plate has the same value as the base material.