As the EV sector continues to grow, there is an increasing emphasis on automotive lightweighting to enhance driving range, improve durability, and ensure safety while achieving better energy efficiency.

Metal 3D printing is uniquely advantageous in the development and optimization of new energy vehicle components and the mass production of traditional component replacements. BLT has applied its expertise to redesign and manufacture a rear sub-frame for an EV client.

The rear sub-frame designed by BLT, measuring 1230mm×845mm×253mm（W×D×H）, is a critical component for improving vehicle comfort, safety, and durability. It interfaces with the chassis at its four corners, with the rear suspension system installed on both sides and central area accommodating powertrain and steering components.

BLT Rear Sub-frame

For optimization, BLT employed Bi-directional Evolutionary Structural Optimization (BESO) to create a superior topological structure. The entire optimization and design process was automated and streamlined by parametric workflows, enabling precise control over local details. The final component features a hollow lattice structure with a 2mm wall thickness, resulting in a weight of around 21kg, a 20% reduction compared to the original hollow cast aluminum design. This redesign also resolved issues related to discontinuous corners caused by limitations in the original manufacturing process. The part was printed by BLT-S815, a large-format system launched in 2023 as part of BLT-S800 platform-based solution. With a build dimension of 800mm×800mm×1500mm（W×D×H）, BLT-S815 allows for the production of larger automotive parts and facilitates design validation, speeding up technological iterations. The part’s mechanical properties, including strength and stiffness, have been verified to meet application requirements.

BLT-S815