User-enabled installation qualification method for laser-based powder bed fusion of metals (PBF-LB/M) machine scanner subsystem

Abstract

Installation qualification for laser-based powder bed fusion of metals (PBF-LB/M) machines is challenging due to the extensive labor, time, and financial costs required by current standards. These standards demand long builds, expensive equipment, and specialized expertise, primarily focusing on mechanical properties, which complicates the analysis of subsystem performance where attention may be required. Consequently, this makes machine installation qualification both inaccessible and inconsistent for typical PBF-LB/M users. This study presents a new methodology for installation qualification of PBF-LB/M scanner subsystem hardware and control software that addresses these challenges, empowering users to qualify their systems. A plate melt setup using a commercially available 25.4-millimeter square stainless-steel plate was designed to characterize scanner performance through a series of “pass” or “attention required” tests assessing laser and scanner delays, scanner acceleration, dimensional accuracy, and slicer file software interpretation. The method was then applied on four PBF-LB/M machines, with one plate scanned per laser under machine original equipment manufacturer (OEM) recommended build conditions. Laser power and scan speed parameters were specified to be the same for the four machines. The results show notable variations in scanner delays, scanner momentum control, and path planning file preparation that impact the results of the laser welding. A simple example of the machine-to-machine variability was captured when three out of the four machines tested were unable to produce dimensionally accurate 1 mm diameter circles. In addition, all machines required attention during numerous tests aimed at slicer file software interpretation, which highlights critical gaps in the physical and programmable scanner control of PBF-LB/M machines. Overall, this study demonstrates the potential of the proposed plate melt method to assess scanner subsystem performance without the challenges of current standards.