Product Code: JLA_6_1_32

Authors:
Anand J. Paul
Parwaiz A. A. Khan
Manufacturing and Materials Division, Concurrent Technologies Corporation, 1450 Scalp Avenue, Johnstown, PA 15904, U.S.A.

Lasers, though developed only about a quarter century ago, are now being routinely used in the automotive, aerospace and other industries to produce superior quality, high‐speed autogenous welds with narrow heat‐affected zones in a number of alloys. However, they cannot at present be used to successfully weld certain important structural alloys due to a change in weld composition resulting from selective mass transport of certain alloying elements from the laser‐melted region. The loss of alloying elements leads to a degradation in mechanical properties of laser‐welded structures. Extensive experimental and theoretical research has previously been conducted to develop a better understanding and control of mass transport that takes place during high‐energy laser welding. In light of the possible use of high‐energy lasers for deep penetration welding of certain hard‐to‐weld structural alloys used in Navy vessels, the approach and results of these mass‐transport studies has been applied to evaluate the suitability of lasers for welding alloys used by the US Navy. Details of the study are discussed.