Monitoring melt pool asymmetry in gas metal arc-directed energy deposition

Abstract

Cross-sectional asymmetry of melt pools along adjacent tracks results in an uneven build surface in gas metal arc-directed energy deposition. We present here a novel attempt on real-time monitoring of melt pool cross-sectional asymmetry in terms of its lateral and angular deviations from the track centreline using a two-colour quotient thermal camera. The melt pool lateral and angular deviations are found to be 2-3 mm, and 8-12°, respectively, for the range of process conditions. A unique analytical methodology is proposed that shows a hatch spacing of around 72-76% of the width of a deposited track can reduce melt pool asymmetry and layer height variations along adjacent tracks, which is also observed experimentally.

Recent progress in process, structure, properties, and performance in additive manufacturing

“…The special issue contains contributions on the major variants of AM including laser DED [6,9,18,24], gas metal arc DED [7,[10][11][12][13][14]16,19,[21][22][23], laser PBF [8], cold spray [17], laser-arc hybrid manufacturing [20], and fused deposition modelling [15]. Chaurasia et al [22] presented a novel approach to real-time monitoring of melt pool cross-sectional asymmetry during laser PBF using a two-color thermal camera. The lateral and angular deviations of the molten pool were 2-3 mm and 8-12°, respectively.…”

“…This special issue includes all aforementioned trends of progress through 19 original research articles [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The editors of STWJ invited active researchers from the AM and welding communities to contribute to this special issue.…”