Round Robin Study Evaluating Consistency of 4340 Steel Specimens Manufactured by Different Laser Powder Bed Fusion Machines

The US Army is evaluating metals additive manufacturing as a next-generation technology to enhance capabilities. To fully benefit from this technology, challenges of manufacturing maturity must be overcome for part qualification and certification. The Combat Capabilities Development Command Armaments Center located at Picatinny Arsenal, NJ, conducted a round robin build demonstration of Laser Powder Bed Fusion (L-PBF) using 4340 steel. Six participants took part in the demonstration, with equipment including the EOSINT M270, EOSINT M280, 3D Systems ProX 300, and SLM 280. Round robin builds consisted of tensile specimens in the horizontal (XY) and vertical (Z) orientations in the four corners and center location of the build platform. The specimens were heat-treated and machined to specifications. The mechanical property test results were analyzed as a function of build plate location and orientation across a series of L-PBF machines. Statistical analysis was used to detect data relationships and general trends.