Increasing the deposition rate of inconel 718 for LMD

Laser Metal Deposition (LMD) is beneficial when applying repairs on components of high complexity such as compressor blades or BLade Integrated diSKS (“BLISKS”). Due to limited deposition rates, the process time for LMD is increased which is a main factor for high production costs. Thus, a significant increase of the deposition rate (factor 10 and higher) is of interest when using LMD for repair and for additive manufacture of entire parts. Goal of the current study is the qualification of LMD as a production and repair process for high-speed repair and additive manufacture of compressor blades and BLISKs made of IN 718 using conventional manufactured disk as a substrate. In a first step studies on appropriate processing parameter combinations for higher deposition rates are carried out using a 10 kW disk laser system. Two strategies are currently examined when building-up single blades. A coaxial powder feeding nozzle is assembled to a zoom optic and guarantees a near-net-shape deposition while a lateral square-shaped powder feeding nozzle together with square shaped laser beam geometry provides higher deposition rates. In a second step, LMD of a blade mock-up is carried out using a variation of the laser beam diameter during the process.