Cross-sectional area measurement by optical and electrical resistance methods for subscale mechanical testing of near-net-shape titanium components

Sub-scale mechanical testing is very attractive for characterizing near-net-shape components by quickly producing large data sets with location- and orientation-specific information. This is particularly useful for titanium components produced by additive manufacturing and powder metallurgy, which have highly process-dependent mechanical properties, complex build geometries, and limited material for testing. However, sub-scale tests require precise measurements of relatively small cross-sectional areas, which is cumbersome with traditional techniques. The authors have developed two alternative methods for quickly obtaining accurate cross-sectional areas of sub-scale titanium tensile specimens, which are referred to as the optical method and the electrical resistance method. Samples tested in this study had cross-sectional areas ranging from 0.184 to 1.12 mm2. The areas obtained using both methods were plotted against the areas obtained using a traditional contact micrometer. Both the optical and resistance methods showed a nearly 1:1 relationship with the traditional method and had very little variance among the data. •Two area measurement methods for sub-scale tensile samples are proposed to characterize near-net-shape titanium components.•Cross-sectional areas of samples can be measured using a rotating sample mount, camera, ImageJ software, and Python code.•Alternatively, a four-point probe technique using material resistivity and Pouillet's Law can calculate sample area.•A nearly 1:1 relationship was shown between areas measured with traditional contact micrometers and with the above methods.