Development and validation of a micro-tensile tester for lead-free solder alloys

Abstract Accurate characterization of material properties is essential for industrial design and development, yet conventional standardized testing methods are not always applicable when only limited material volumes are available or when component dimensions are too small. In such cases, miniaturized specimen testing offers a promising alternative, although its reliable transfer into industrial practice remains a challenge. The present work aims to develop a testing system capable of evaluating miniaturized specimens, including in-situ measurements under a microscope. The design emphasizes precise uniaxial alignment and incorporates a high-resolution load measurement system with an error less than 0.09 N to ensure accuracy at small scales. Special attention is given to minimizing unwanted specimen displacement during in-situ observations, which is critical at high magnifications. In parallel, specimen geometry and fabrication methods are optimized to obtain reproducible results without requiring post-processing. As a first step, miniaturized tensile specimens were produced by casting. The measurement system is controlled by an Arduino Uno, which regulates motion and records force data, while displacement is calculated from stepper motor rotation. The resulting force–displacement curves demonstrate the feasibility of the approach and provide the basis for further refinement of miniaturized mechanical testing systems.