Laser clad overlays provide enhanced corrosion and wear performance for components across a wide range of industries. Powder fed laser processes provide flexibility in material selection however, have traditionally yielded lower material usage efficiency (60-80%) compared to wire fed processes. A general model was developed to predict powder catchment efficiency based on the overlap between the weld pool and powder cloud distribution. Mathematical techniques of asymptotic analysis and blending were used to obtain closed-form expressions relating the weld pool leading length (xf) and maximum width (ym) to tabulated material properties and the key process parameters. The powder cloud was mapped with a novel technique using measurements of the mass flow rate at discrete points to reconstruct the complete distribution. For baseline cladding conditions, xf and ym were found to be smaller than the powder cloud leading to catchment inefficiency. A custom laser optics adjustment module was designed to shift the powder cloud relative to the molten pool. Combining optimized parameters with a shift of only 1mm, catchment efficiency >90% was achieved under industrial conditions. This work is part of a broader program at Apollo-Clad, using simple, accurate, and fast analytical modelling techniques to generate engineering design rules for laser-based processes.

Moderated by: Mark Schneider / Jakob Olofsson