FOCUS ON ADDITIVE MANUFACTURING
Author biography
Dr . Filomeno Martina cofounded WAAM3D in July 2018 with a research team from Cranfield University , UK , where he was a senior lecturer Dr . Filomeno Martina . and researcher . His achievements whilst in academia include coordinating a € 1-million EU Erasmus project to set up at Cranfield University “ the first ever MSc in Metal AM in the world .”
He has contributed to the writing and coordination of several successful multi-million-pound bids and projects . During his PhD and post-doc work , he achieved better than wrought properties with alloys of titanium , nickel and iron , with a now patented combination of AM and in-process cold work of the deposit . Filomeno was also a key member of the team who made the world ’ s largest single titanium part by AM ; a Eurofighter Typhoon primary frame structure of 2.5m x 1.5m .
He is a regular speaker on WAAM at conferences globally and has over 40 peer-reviewed journal articles , some of which have been cited over 1,400 times . He has also helped draft ASTM and BSI standards on DED and WAAM . He was also given the prestigious International Outstanding Young Researcher in Freeform and Additive Manufacturing Award ( FAME Jr ) at the 2022 Solid Freeform Fabrication Symposium .
Wire Arc Additive Manufacturing ( WAAM ®) is a 3D metal printing technique that brings a wide range of benefits to large-scale aerospace prototype and component production
associated with machining materials such as titanium and can create less complex , mediumto-large scale structures in a range of materials ( from titanium , aluminium , refractory metals , steel , bronze and copper to Invar ®, Inconel ® and magnesium ). It is particularly suitable for building medium to large aircraft components such as cruciform , flanges , stiffened panels and wing ribs .
AM prototypes
All 3D metal printing , or additive manufacturing ( AM ), processes follow the same procedure for creating a prototype . They are all based on the translation of a 3D model , usually a 3D computer-aided design ( CAD ) file , into a series of layers that creates the final 3D shape .
These digital CAD designs can be easily altered between prototypes and the dissemination of the final design to other parties is straightforward . However , it is the bead dimensions of the deposited material , the slicing routines and the AM process capability that are critical to determine the complexity of the finished prototype .
Only a few AM processes offer the potential to produce fully dense metal components ( Murr et al . 2013 ; Uriondo et al . 2015 ; Sun et al . 2013 ) with similar mechanical properties as traditional methods . They are therefore suitable for aerospace applications ( Joshi & Sheikh 2015 ; Uriondo et al . 2015 ).
When it comes to 3D metal printing , there are four AM processes that are particularly appropriate for aerospace prototype and component applications . These are Laser Powder Bed Fusion ( LPBF ), Electron Beam Powder Bed Fusion ( EBPBF ), Wire Arc Additive Manufacturing ( WAAM ®) and Laser Metal Deposition ( LMD ). A literature review of the four processes used in the aerospace industry shows their different technical parameters ( Editor ’ s note : ibid ).
As can be seen by the data in the table overleaf , some of the processes offer greater design complexity and size options than others . When deciding on which AM process to pursue for an aerospace prototype , the following needs to be considered :
■ What is the minimum required feature size in the component ? Due to layer height and melt pool width dynamics , the starting point for the prototype development process selection must be the minimum required feature size of the component .
■ What surface finish will the end component require ? The natural shape of the weld pool during the build process leads to a scalloped outside surface .
Main images : Thales Alenia Space , WAAM3D , Cranfield University and Glenalmond Technologies first full-scale prototype of a titanium pressure vessel to be used in future manned missions for space exploration .
ISMR July / August 2023 | ismr . net | 19