A mechanical characterization of SLA 3D-printed specimens for low-budget applications

Stereolithography (SLA) is becoming a more and more popular 3D-printing method. Improvement in material properties encourages makers and engineers to embrace this technology even for load-bearing applications. Mechanical properties of 3D-printed materials are difficult to obtain from technical datasheets and, even when available, these data are often unreliable, since they depend strongly on the specific printing parameters applied. Therefore, it is often necessary to perform an in-house mechanical characterization. In this work, tensile tests are performed with a basic in-house-designed tester on SLA 3D-printed specimens; these are printed at different orientations on a Formlabs™ Form 2™ using Clear V4™ resin. The ultimate tensile strength, Young’s modulus, strain at maximum stress and strain at break are calculated. No relationship is found between printing angle and mechanical characteristics; therefore, this 3D-printed material can be considered isotropic. Results are compared with the manufacturer’s datasheet: the measured maximum stress is slightly lower than that stated by Formlabs™, while the modulus is nearly the same. Strain at maximum stress and strain at break were also measured but were not reported in the available datasheet.