A process for the production of articles made of a gamma-prime precipitation-strengthened nickel-base superalloy by selective laser melting (SLM)

A process for the production of crack-free and dense three-dimensional articles made of a gamma-prime precipitation-strengthened nickel-base superalloy, comprising more than 6 wt.- % of [2 Al (wt. -%) + Ti (wt. -%)], by selective laser melting (SLM) comprises the steps of: a) providing an SLM apparatus (10) with an SLM control unit (19); b) providing a three-dimensional sliced model (SM) of said article with calculated cross sections, which is passed to and stored in said SLM control unit (19); c) preparing powder of said gamma-prime precipitation-strengthened nickel-base alloy material, which is needed for said SLM process; d) preparing a powder layer (18) with a regular and uniform thickness on a substrate plate (13) of said SLM apparatus (10) or on a previously processed powder layer (14); e) melting said prepared powder layer (18) by scanning with a focused laser beam (17) an area corresponding to a cross section of said article according to the three-dimensional sliced model (SM) stored in said control unit (19); f) lowering the substrate plate (13) by one layer thickness; g) repeating steps from d) to f) until reaching the last cross section according to the three-dimensional sliced model (SM); wherein for said melting step e) the laser power, focus diameter (d) of the focal spot (20) and scan speed of said focused laser beam (17) are adjusted to obtain heat dissipation welding.