Implications of lattice structures on economics and productivity of metal powder bed fusion

The cost-effectiveness of metal powder bed fusion (PBF) systems in high-throughput production are dominated by the high cost of metallic powder materials. Metal PBF technologies become more competitive in production scenarios when Design for Additive Manufacturing (DfAM) is integrated to embed functionality through shape complexity, weight, and material reduction through topology optimization and lattice structures. This study investigates the value of DfAM in terms of unit cost and manufacturing time reduction. Input design parameters, such as lattice design-type, part size, volume fraction, material type and production volumes are included in a Design-of-Experiment to model their impact. The performance variables for cost and manufacturing time were assessed for two scenarios: (i) outsourcing scenario using an online quotation system, and (ii) in-house scenario utilizing a decision support system (DSS) for metal PBF. The results indicate that the size of the part and the lattice volume fraction are the most significant parameters that contribute to time and cost savings. This study shows that full utilization of build platforms by volume-optimized parts, high production volumes, and reduction of volume fraction lead to substantial benefits for metal PBF industrialization. Integration of DfAM and lattice designs for lightweight part production can decrease the unit cost of production down to 70.6% and manufacturing time can be reduced significantly down to 71.7% depending on the manufacturing scenarios and design constraints when comparing to solid infill designs. The study also provides a case example of a bracket design whose cost is reduced by 53.7%, manufacturing time is reduced by 54.3 %, and the overall weight is reduced significantly with the use of lattices structures and topology optimization.