Application of NDT active thermography for the characterisation of the cold spray process of high-entropy alloys.

A Non-Destructive technique (NDT) based on Active Thermography (AT) is proposed to correlate mechanical properties, process parameters and thermal response for High-Entropy Alloys (HEA) coatings. More in detail, the Pulsed technique is utilised to investigate thermal responses generated by different High-Entropy Alloys (HEA) coatings. In particular, specimens tested in this work are made of several chemical compositions (AlxCoCrCuFeNi and MnCoCrCuFeNi) and are realised by using different Cold Spray temperatures (650°C, 750°C and 850°C), generating coatings with various mechanical properties. This way, results in terms of thermal responses obtained with a Non-Destructive technique are correlated, by means of ANOVA, with the corresponding chemical compositions and process parameters of each specimen. The impact of both roughness and emissivity on the process characterisation was also investigated. [ABSTRACT FROM AUTHOR]