Accelerated Mechanical Testing: Profilometry-Based Indentation Plastometry (PIP) for Space & Aerospace Alloy Characterisation

Mechanical testing is fundamental to the qualification and certification of materials for safety-critical aerospace and space applications. Conventional tensile testing, however, remains time and cost intensive, requiring significant sample preparation, machining, and testing infrastructure. As additive manufacturing (AM) continues to gain traction within these sectors, its inherent sensitivities, spanning process parameters, heat treatment conditions, and part geometry, necessitate extensive mechanical characterisation to ensure component reliability. The resulting testing burden highlights the need for faster, more flexible, and non-destructive alternatives to traditional methods.

Profilometry-Based Indentation Plastometry (PIP) offers an alternative methodology. Using a macroscopic indentation (50–200 µm deep), PIP captures the full indent profile and applies an accelerated inverse finite element analysis to extract a complete stress–strain curve, including yield strength and ultimate tensile strength. Applicable to a wide range of metallic materials, PIP testing provides mechanical data in under five minutes with minimal surface preparation. Furthermore, PIP can also be conducted at elevated temperatures up to 800 °C, extending its utility to high-temperature aerospace alloys.

Two recent collaborative studies with NASA demonstrate the technique’s versatility for AM component evaluation. The first investigated a laser powder bed fusion (LPBF) NASA HR-1 c-ring, mapping mechanical property variation both up the build height and across changing cross-sections. PIP revealed localised property gradients associated with thermal history and geometry-dependent cooling rates. The second study examined NASA HR-2 alloy at elevated temperatures, assessing the sensitivity of plasticity behaviour to heat treatment variations. The rapid testing capability of PIP enabled a systematic exploration of process–property relationships within hours rather than weeks.

These studies highlight PIP as a tool for accelerated, spatially resolved, and high-temperature mechanical characterisation of aerospace and space alloys, supporting the rapid qualification of next-generation AM materials.