Minimising lattice defects with additive manufacturing

Providing a reliable way to predict how new lattice designs can be fine-tuned to minimise structural defects.

The design and construction of lattice materials relies on a delicate balance of structural factors. Researchers at the University of Glasgow have been investigating the deformation mechanisms which cause 3D printed materials to fail under strain, culminating in a new design parameter called the ‘enhancement factor’.

“The enhancement factor tool is designed to bridge the gap between theoretical predictions and the actual performance of 3D printed lattice structures, helping engineers to optimise their designs,” says Professor Kumar Shanmugam, professor of composite materials and advanced manufacturing at the University of Glasgow. “The tool acts as a corrective factor that quantifies the discrepancy between the ideal, defect-free lattice structure and the real, printed version, which may be affected by various factors such as printing defects and deposition strategy.”

STRUCTURAL BENEFITS

According to Shanmugam, lattice designs offer many significant benefits for industrial parts, primarily due to their unique structure. “One of the primary advantages of lattice materials is their ability to achieve high specific strength and stiffness, making them ideal for structural applications,” he explains. “Additionally, their capacity to absorb energy makes them suitable for impact resistance and shock mitigation. This versatility enhances the performance of industrial components, particularly in applications requiring both strength and weight reduction.”

Lightweighting is also an important advantage of lattice designs. “The lightweight nature of lattice-designed components is a crucial advantage across industries like automotive, aerospace, robotics and biomedical fields, where reducing weight without compromising performance is essential,” he adds.

MEET THE CHALLENGE

Additive manufacturing has emerged as an ideal production technology for developing new lattice designs, however challenges remain. Shanmugam’s team focused on overcoming these issues to produce structures with minimal defects, porosity and dimensional inconsistencies using 3D printing.

“Engineers often rely on established theoretical models to predict stiffness, strength and energy absorption of lattice structures,” Shanmugam says. “However, these models are typically based on ideal conditions or on materials produced through traditional manufacturing methods. When it comes to additive manufacturing, the actual mechanical properties of the printed structures can differ significantly due to the unique challenges of the process.”

The team’s enhancement factor tool is designed to provide a practical means to connect theoretical mechanical properties to those of the actual 3D printed structures. “Engineers can assess the effective mechanical performance of their designs, accounting for the real-world imperfections introduced during the printing process,” he continues. “This enables them to make more informed decisions about material selection, lattice architecture and process parameters, ultimately improving the performance and reliability of the final product. Moreover, the enhancement factor tool serves as a diagnostic metric for the quality of the printing process.”

By adhering to these guidelines, engineers can design 3D printed lattices that are not only robust, but also optimised for advanced applications, he adds.

“Our research holds significant potential for advancing component design and material development across various industrial applications. In automotive, flawlessly produced lattice materials could revolutionise road safety, in aerospace, engineers could develop more fuel-efficient aircraft, and customised implants made from 3D printed lattice materials could improve patient outcomes.”

Read the full research paper here.