Authors:
X. Cao
Aerospace Manufacturing Technology Centre, Institute for Aerospace Research, National Research Council Canada, 5145 Decelles Ave., Montreal, Quebec H3T 2B2, Canada

G. Debaecker
Ecole Centrale de Nantes, 1 Rue de la Noe´, B.P. 92101, 44321 Nantes Cedex 3, France

E. Poirier
Aerospace Manufacturing Technology Centre, Institute for Aerospace Research, National Research Council Canada, 5145 Decelles Ave., Montreal, Quebec H3T 2B2, Canada

S. Marya
Ecole Centrale de Nantes, 1 Rue de la Noe´, B.P. 92101, 44321 Nantes Cedex 3, France

J. Cuddy
A. Birur
Standard Aero Limited, 33 Allen Dyne Road, Winnipeg, Manitoba R3H 1A1, Canada

P. Wanjara
Aerospace Manufacturing Technology Centre, Institute for Aerospace Research, National Research Council Canada, 5145 Decelles Ave., Montreal, Quebec H3T 2B2, Canada

The effect of joint gap on the butt joint quality of Ti-6Al-4V alloy welded using a 4 kW Nd:yttrium aluminum garnet laser was evaluated in terms of the welding defects, microstructure, hardness, and tensile properties. The joint gap was proportionally filled using the filler wire with the compositions of the parent alloy. Fully penetrated welds without cracking were obtained up to a joint gap of 0.5 mm. The main defects observed in the welds were porosity and underfill. Specifically, the porosity area increased with increasing joint gap but remained less than 1% of the fusion zone area. Large underfill defects appeared in the weldments in the absence of a joint gap, but filler wire addition was observed to reduce this defect in the presence of a joint gap. The weld hardness decreased slightly with increasing joint gap, but the tensile properties were optimized at an intermediary gap size, probably due to the compromise between the low underfill (after the use of a filler wire) and a limited amount of porosity.