Testing materials under the conditions they’re likely to experience in service is vital to understand both performance and lifetime. For many components, this involves exposure to high temperatures, whether that’s in an aerospace engine or a large-scale bakery oven. Traditionally, high-temperature tensile testing has been the gold standard for assessing mechanical properties in such conditions. However, this method demands highly specific testing samples, leading to significant costs, operational complexity, and in some cases, making high-temperature testing impractical or even unfeasible.

In this case study with Renishaw, we uncover how the varying temperatures throughout a furnace have a significant impact on the mechanical properties of AM parts, in this case showing over 10% variation in yield strength, and how these findings have led Renishaw to optimise their heat treatment process, ensuring consistency and increasing confidence in part performance.

Where machining tensile specimens for testing is not an option, hardness is often considered as a solution. This poses a significant limitation; while hardness testing offers advantages such as affordability, speed, ease of use, and suitability for testing small specimens, a hardness number is not a fundamental material property. Furthermore, practitioners are limited to conversions into a limited set of material property values, as hardness numbers cannot give full stress-strain curves, which means that without further information finite element modelling cannot always be conducted accurately.