This investigation covers the eventual formulation of a standardized testing coupon that can be used to evaluate compression strength of a lattice design. This is generally intended to be used in validation or verification activities for an additively manufactured component that incorporates a lattice or porous (non-solid) design. Due to inherent variability across the manufacturing of AM components, evaluation methods are needed. Specifically, when an eventual component is intended to be subjected to compressive loads, a representative testing coupon is needed to represent the component to undergo destructive evaluation as a surrogate for the component itself. This standardized test coupon will accommodate the application of a variety of lattice designs, while standardizing the evaluation method. Details may include limits or requirements for minimum repeated elements and relative dimensions of the specimen.
Gyroid; 3d printing; additive manufacturing; unit cell; compression testing
Due to inherent variability of the additive manufacturing process, consistent manufacture of components is of greater concern than traditional subtractive methods. The validation and verification activities to support the manufacture of components is critical in the quality systems to reliably produce consistent parts. There is a growing usage of lattice or porous designs due to the design flexibility afforded by AM; however, each manufacturing system may have different capabilities in terms of resolution of features as well as resultant strength. However, the need for the components to be used requires the development of standardized coupons that may be used as a surrogate in destructive evaluations. These applications include latticed or porous components that are placed under compressive loads. Since each lattice design is potentially different for all manufacturers, a standardized method is needed to ensure that the lattice design is adequately represented and can be consistently assessed. This would allow for the evaluation of the compressive mechanical strength with adequate representation of the manufacturing of the lattice design. Although ASTM E9 provides standard methods of compression testing for metallic materials, specific considerations for lattice structures, such as the minimum number of unit cells are not included.
The title and scope are in draft form and are under development within this ASTM Committee.
Developed by Subcommittee: F42.01
Staff Manager: Pat Picariello
Date Initiated: 03-05-2021
Technical Contact: Matthew Di Prima