Abstract

Rapid solidification of aluminium alloys during the remelting process using high power laser radiation results in refining effects of the solidified grain texture and improved wear resistance and material hardness. High temperature gradients can be achieved as well as energy coupling into the aluminium alloy is locally restricted, and can be precisely controlled. For the adjustment of defined grain textures, the dynamic behaviour of the melted material on the irradiated material surface is of high interest. Most of the optical set-ups currently used for process visualisation only image the plasma formation within the laser beam interaction zone. Available systems for frequency-selective irradiation and visualisation provide insufficient time resolutions with respect to rapid melting and solidifying processes.

© 1998 IEEE