A Mathematical Programming Model for Minimizing Energy Consumption on a Selective Laser Melting Machine

Abstract

The scheduling problem in additive manufacturing is receiving increasing attention; however, few have considered the effect of scheduling decisions on machine energy consumption. This research focuses on the nesting and scheduling problem of a single selective laser melting (SLM) machine to reduce total energy consumption. Based on an energy consumption model, a nesting and scheduling problem is formulated, and a mixed integer linear programming model is proposed. This model simultaneously determines part-to-batch assignments, part placement in the batch, and the choice of build orientation to reduce the total energy consumption of the SLM machine. The energy-saving potential of the model is validated through numerical experiments. Additionally, the effect of the number of alternative build orientations on energy consumption is explored.

Figures (7)

• Figure S1: A batch of parts with different build orientations.
• Figure S2: Working status of different machine subsystems during the SLM process. The dark color, light color, and blank areas represent the subsystems running all the time, intermittently, and out of service.
• Figure S3: The placement for the scheduling by MILP and Magics on ec_20-5: (a) Magics Batch 1; (b) Magics Batch 2; (c) MILP Batch 1; and (d) MILP Batch 2.
• Figure S4: The duration of different subprocesses. Ph is preheating, sb is scan border, vh is volume hatching, ss is support structure, rc is powder spreading, and co is cooling.
• Figure S5: The energy consumption of different subprocesses. Ph is preheating, sb is scan border, vh is volume hatching, ss is support structure, rc is powder spreading, and co is cooling.