Additively Manufactured Patterns on Structural Materials for High Temperature Digital Image Correlation

Abstract Accurate and reliable real-time monitoring of material deformation in harsh environments remains a significant challenge. Non-contact techniques, such as digital image correlation (DIC), offer a promising solution for in-situ strain measurements where traditional contact sensors face limitations. In this work, aerosol jet printing (AJP) was used to fabricate repeatable DIC patterns through the deposition of silver and iron oxide nanoparticles on stainless steel 316L, a common structural material. Samples were tensile tested at elevated temperatures (up to 600 °C). DIC calculated strain from additively manufactured printed patterns was compared to the strain associated with traditional random, spray painted patterns as well as strain measured by an extensometer. In addition, DIC printed silver dots with 150 µm pitch spacing and iron oxide dots with 250 µm pitch spacing had relative errors at 11.4% and 4.7%, respectively, at 600 °C when compared to extensometer measurements likely do material property differences from the bulk material and DIC pattern as well as heat haze interference on the images captured. These results indicate that printed DIC strain measurements had no statistical significance to the strain recorded by the extensometer measurements.