FOCUS ON ADDITIVE MANUFACTURING
Parameter LPBF EBPBF LMD WAAM
Energy ( W ) |
100 - 1000 ( Bhavar et al . 2014 ) |
~ 3500 ( Baumers et al . 2016 ) |
~ 500 – 3000 ( Cao & Gu 2015 ) |
2000 – 4000 ( D . Ding et al . 2015b ) |
Overall Process Efficiency |
2 % – 5 % ( D . Ding et al . 2015b ) |
15 % – 20 % ( D . Ding et al . 2015b ) |
2 – 5 % ( D . Ding et al . 2015b ) |
~ 70 % ( Ríos et al . 2018 ) |
Dimensional Accuracy ( mm ) |
± 0.04 ( Gu 2015 ) |
± 0.05 ( D . Ding et al . 2015a ) |
± 0.13 ( D . Ding et al . 2015b ) |
± 0.2 ( D . Ding et al . 2015b ) |
Build Rates ( for Ti6Al4V ) ( Kg / h ) |
0.1 – 0.18 ( Bhavar et al . 2014 ) |
0.26 – 0.36 ( Dutta & Froes 2017 ) |
0.1 – 1.41 ( Dutta & Froes 2017 ) |
0.5 – 4 ( Williams 2016b ) |
Maximum Build Volume ( mm x mm x mm ) |
500 x 350 x 300 ( Bhavar et al . 2014 ) |
200 x 200 x 180 ( Bhavar et al . 2014 ) |
900 x 1500 x 900 ( Frazier 2014 ) |
Potentially unlimited ( Williams 2016b ) |
Layer Thickness ( μm ) |
20 – 100 ( Gu 2015 ; Ruban et al . 2014 ) |
~ 100 ( Murr et al . 2012 ) |
500 – 1000 ( Dutta & Froes 2017 ) |
1000 – 2000 ( S . W . Williams et al . 2016 ) |
Surface Roughness ( μm ) |
4 – 11 ( Vayre et al . 2012 ; Gu 2015 ) |
25 – 35 ( Vayre et al . 2012 ) |
20 – 50 ( Gu 2015 ; Dutta & Froes 2017 ) |
500 ( S . W . Williams et al . 2016 ) |
Minimum Feature Size ( μm ) |
40 – 200 ( Bhavar et al . 2014 ) |
100 ( Bhavar et al . 2014 ) |
150 – 200 ( Mahamood et al . 2013 ) |
2000 ( Williams 2016 ) |
A team featuring Thales Alenia Space ; WAAM3D ; Cranfield University and Glenalmond Technologies has successfully produced a first full-scale prototype of a titanium pressure vessel to be used in future manned missions for space exploration
What is WAAM ?
Wire Arc Additive Manufacturing ( WAAM ) features two main arc processes : Plasma Transferred Arc ( PTA ) and Metal Inert Gas ( MIG ). In addition , WAAM3D offers a patented addition of in-process cold-work . This has brought mechanical deformation back into the picture , with plastic strain introduced as frequently as required , in between WAAM deposition passes .
“ With this , a forged-like level of strength is possible and you can reap all the cost , time and environmental benefits of WAAM without compromising on performance ,” explained WAAM3D .
The size of these scallops will depend upon the bead height laid down . The surface of the metal prototype , and future components created , might need finishing if specific smooth or polished surfaces are required .
WAAM for larger prototypes
There is inevitably a trade-off in AM processes between surface finish and component size . For complex designs with thin walls LPBF is ideal , as it relies on finer particles and laser spot sizes . However , it is not suitable to produce large components .
One technique that has the potential to transform large-scale aerospace prototype and component production is WAAM . This is because it avoids the expensive waste associated with machining materials such as titanium and can create less complex , medium-to-large scale structures in a range of materials ( from titanium , aluminium , refractory metals , steel , bronze and copper to Invar , nickel superalloys and magnesium ). It is particularly suitable for building medium to large components such as cruciform , stiffened panels , wing ribs and flanges , impellers , tanks etc .
WAAM prototype ( a titanium pressure vessel for space exploration )
A team featuring Thales Alenia Space ; WAAM3D ; Cranfield University and Glenalmond Technologies has successfully produced a first full-scale prototype of a titanium pressure vessel to be used in future manned missions for space exploration .
The vessel is approximately one metre in height and 8.5kg in mass . Made of the titanium alloy Ti-6Al-4V , it has been deposited using the WAAM process .
As it is possible to go straight from digital
20 | ismr . net | ISMR July / August 2023