Laser strip cladding for large area metal deposition

Abstract

Directed energy deposition (DED) processes frequently rely on metallic powder and wire feedstock materials. Several grades of metallic strips are, however, commercially available but not yet largely utilized in DED. This paper introduces a newly developed laser strip cladding process, which can be used for surfacing, repair and additive manufacturing. Cladding tests consisted of single-layer single- and multi-bead tests on planar and round bar type base materials using a 30 mm wide solid Alloy 625 strip. The results showed that with 8 kW laser power 34 mm wide and ˜2 mm thick single beads on steel could be produced with low dilution and fusion bond with high deposition (8 kg/h) rates. In multi-bead tests, coverage rates of 0.45 m2/h were reached. Corrosion performance of clad deposit was influenced by the inhomogeneous distribution of intermixed iron from the base material on a test surface. In addition to high productivity, the developed process takes advantage of large build volume (>1 m3) and full material utilization as well as clean process conditions.