Application of the ABA cladding technique to a wire based laser cladding process

Abstract

In this study, the application of the ABA cladding strategy in coaxial wire-based cladding processes is investigated. Individual weld seams (A) are first welded on the substrate and additional weld seams (B) are deposited into the intermediate spaces in the second step. Thereby, two different seam geometries are present in the cladding. Unidirectional AAA and ABA claddings are generated using laser hot-wire cladding and analyzed with respect to the quality criteria height, waviness, degree of dilution, and defects. Three different welding parameter sets are used to consider the effect of the contact angle on the applicability of the ABA cladding strategy. When the same process parameters and seam-to-seam offsets are used for the ABA cladding, as for the AAA cladding, the B weld seams are higher than the A weld seams and an uneven ridged cladding surface is present. Two approaches to solving this problem are considered. The cross-sectional area of the B weld seams is reduced by adjusting the welding speeds or an increase in the seam-to-seam offset. Both measures result in a significant reduction in waviness of 30%–58% compared to the AAA cladding. However, lack of fusion defects occurs more frequently at the deposition regime of the B weld seams. It was, therefore, necessary to adjust the process parameters for weld seam B.