Small Punch Testing of Electron Beam Melted (EBM) Ti‐6Al‐4V

Abstract

The use of additive layer manufacturing (ALM) processes such as electron beam melting (EBM) is becoming increasingly prevalent in the aerospace industry. The safety critical nature, coupled with the arduous operating conditions to which these additive manufactured components will be exposed mean that it is crucial that the mechanical properties of the processed materials can be characterised. The microstructure, and hence mechanical properties of EBM structures, can be influenced by both component and build geometry, leading to difficulties in characterising components. Small punch (SP) testing enables mechanical test comparisons across small quantities of material. SP test specimens can be extracted from complex and component representative geometries to compare the local mechanical response of the material. This work assesses the potential of the SP test technique for characterising the mechanical properties of Ti-6-4 EBM components.

Mechanical Property Characterisation of Electron Beam Melted (EBM) Ti-6Al-4V via Small Punch Tensile Testing

“…The specimens were observed at low magnifications where the protruding region of material could be viewed in its entirety, as well as at higher magnifications to highlight fractographic features of interest. responses of the different material variants at room temperature as previously outlined [17]. Furthermore, the contrasting behaviours are also seen at elevated temperature, but to a lesser extent.…”

“…In recent years research has been targeted towards exploiting the potential of SP testing within the aerospace industry for characterising novel materials and processes where material quantities are limited [15,16]. Furthermore, the potential of the technique to evaluate the properties of ALM materials has also begun to be explored [17,18]. The difficulties in ensuring that any specimens being produced for conventional uniaxial mechanical testing have component representative microstructures and hence mechanical properties has promoted the use of SP testing as an ideal solution.…”

Martensite Decomposition and Ultrafine Grain Formation during Small Punch Creep Testing of Additively Manufactured Ti64

“…The SPCT technique was mainly used for studying the creep properties of power plant steels [8,13,[15][16][17][18][19] and has recently been extended to the study of nickel-based superalloys [20]. Regarding the behaviour of the Ti64 alloy, the small punch technique was used to study yielding in both wrought and AM elaborated materials through SPT testing [21][22][23]. However, the creep behaviour of AM Ti64 was only studied using uniaxial tests either in compression or tensile mode [24][25][26].…”