Micro Specimen Mechanical Test

Micro tensile testing is a specialized technique used to evaluate the mechanical properties of materials at small scales, offering critical insights into their strength, ductility, and elastic behavior. I employed a custom micro-mechanical testing setup to study Selective Laser Melted Inconel 718, focusing on its tensile and fatigue properties. This setup, controlled by a flexible Python script, allows precise control over testing parameters and data acquisition, making it ideal for analyzing small-scale samples like thin-wall and bulk dogbones. By integrating a Futek LSB302 load cell for force measurement and a Transmotec DLA linear actuator with a JRK G2 controller for displacement, the system ensures accurate and repeatable testing. A linear air bearing minimizes friction and maintains alignment, enabling high-fidelity data collection.

To capture strain data, I paired the setup with a Vic-2D Digital Image Correlation (DIC) system from Correlated Solutions, using Vic-Gauge software and a Basler Ace acA2440 camera to record 5MP monochrome images at up to 75fps. This allowed detailed, non-contact strain mapping across the sample surface, revealing localized deformation and failure patterns. The testing protocol involved displacement-controlled tensile tests at a strain rate of ~10⁻⁴/s, with samples preloaded to 50 MPa for consistency, followed by load-unload cycles to determine elastic modulus and yield strength. Fatigue tests used a load control scheme, cycling samples at specific stress levels (e.g., 650–850 MPa) to study crack initiation and propagation. This micro tensile setup’s precision and flexibility make it a powerful tool for characterizing advanced materials, providing data that informs material design and performance in demanding applications.