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Wire + Arc Additive Manufacture of non-ferrous alloys – current status and materialproperties
Presented by Stewart Williams
Welding Engineering and Laser Processing Centrewww.waammat.com
Topics
• Very brief summary of Wire + Arc Additive Manufacture
• WAAM non-ferrous materials
– Titanium 64
– Aluminium
– Refractory metals
– New and mixed materials
• Future prospects
Key WAAM process features
• Build rates 0.5 - 4 kg/hour – typical 1kg/hr titanium
• Unlimited build volume
• Fully dense materials with excellent mechanical properties
• Minimum feature size 2 mm
• No commercial systems available – yet
Machined part
Effect of deposition strategy – Ti64
• Each will result in different cooling rates different microstructuresdifferent mechanical properties
18
mm
4 mm
a) single pass
b) parallel passes
c) oscillation
4m
m
Unique features // High pressurerolling
Ti64 // Microstructure with rolling
Control Profiled @ 50 kN
Profiled @ 75 kN
Flat @ 50 kN
Flat @ 75 kN
125 μm 89 μm 139 μm 66 μm
WAAM Ti64 without and withrolling (average)
750 800 850 900 950 1000 1050
Proof strength (MPa)
850
900
950
1000
1050
1100
Ulti
ma
tete
nsi
lest
rength
(MP
a)
Cast ASTM F1108
Wrought AMS 4928
Additive AMS 4999
Single
Par.
Oscill.
50 kN
75 kN
Plate
750 800 850 900 950 1000 1050
Proof strength (MPa)
6
8
10
12
14
16
18
20
22
Elo
ng
atio
n(%
)
Cast ASTM F1108
Wrought AMS 4928
Additive AMS 4999
With rolling (direction)
The effect of build/cooling rates
0.1 1 10
Build rate (kg/h)
800
850
900
950
1000
1050
1100
Pro
ofst
ren
gth
(MP
a)
WAAM Single
WAAM Par.
WAAM Oscill.
SLM
EBM
HiDR
Blown powder
0.1 1 10
Build rate (kg/h)
900
950
1000
1050
1100
1150
1200
Ulti
ma
tete
nsi
lest
ren
gth
(MP
a)
WAAM Single
WAAM Par.
WAAM Oscill.
SLM
EBM
HiDR
Blown powder
0.1 1 10
Build rate (kg/h)
6
8
10
12
14
16
18
Elo
ng
atio
n(%
)
WAAM Single
WAAM Par.
WAAM Oscill.
SLM
EBM
HiDR
Blown powder
The effect of build/cooling rates
Laser powder bed
EB powderbed
Laser blownpowder
Arc+wire
Fatigue Vs Specimen direction
R-Ratio 0.1, σmax=600MPa,Sinusoidal Waveform and 30Hz,
WroughtTi64
WAAM
•Wrought material initiates atprimary α particle or casting pores
•WAAM material does not initiate
(in this test) or initiates at very
isolated pores due to wire
contamination
Improved fatigue performance
heterogeneous bi-modal (duplex) microstructure
Ti64 // Rolling and FCGR of WAAMmaterial unrolled and rolled
1x10-9
1x10-8
1x10-7
1x10-6
1x10-5
1x10-4
1 10 100
da/d
n(m
m/c
ycle
)
∆K (MPa √m)
NASA
Control H1
Control H2
Control V1
Control V2
Rolled H1
Rolled H2
Rolled V1
Rolled V2
Ti64 // Fracture toughness
500
10
0
substrate
buildingdirection
deposited layers
alongthe
layers
acrossthe
layers
WAAM material
TI64 Crack growth trajectory at theinterface
AM
Substrate
Crack trajectorymaintains almost a
straight line
AM
Substrate
Crack trajectorymaintains almost a
straight line
substrate
buildingdirection4
0
87.5 84
60
12
0
445
40
33
WAAM material
interface
A B CD
E
Ti64 // FCGR and interface
substrate
buildingdirection4
0
87.5 84
60
12
0
445
40
33
WAAM material
interface
A B CD
E
• C is 43-100%greater
• B is the best ofthis subset
• WAAM materialhas the slowestgrowth rate andis isotropic
WAAM aluminium 2319
120 140 160 180 200 220 240 260 280 300 320
Proof strength (MPa)
260
280
300
320
340
360
380
400
420
440
460
Ulti
mate
ten
sile
stre
ng
th(M
Pa)
Single
Single T6
15 kN
30 kN
45 kN
45 kN T6
Wrought T6
120 140 160 180 200 220 240 260 280 300 320
Proof strength (MPa)
7
8
9
10
11
12
13
14
15
16
17
Elo
ng
atio
n(%
)
Single
Single T6
15 kN
30 kN
45 kN
45 kN T6
Wrought T6
WAAM aluminium alloys 4043 and5087
60 80 100 120 140 160 180 200 220 240
Proof strength (MPa)
160
180
200
220
240
260
280
300
320
340
360
Ulti
mate
ten
sile
stre
ng
th(M
Pa)
4043
5087
5087 + rolling
60 80 100 120 140 160 180 200 220 240
Proof strength (MPa)
19
19.5
20
20.5
21
21.5
22
Elo
ng
atio
n(%
)
4043
5087
5087 + rolling
Composition control using multiplefeeds
1 wire Al6%Cu– 100HV2 wire (Al4.5%Cu1.5%Mg) – 120HV
3 wire (Al8%Cu1.5%Mg – 140HV)
Wire + Powder
Multi wire approach
Aluminium alloy variable Si/Mgcomposition & hardness
Aluminum alloy variable Cu/Mgcomposition
Wires: 2319+5087; Substrate: 2219
Tested Cu/Mg composition & hardness
WAAM aluminium 2024
150 200 250 300 350 400 450
Proof strength (MPa)
250
300
350
400
450
500
Ulti
mate
ten
sile
stre
ng
th(M
Pa)
Single
Single T6
15 kN
30 kN
45 kN
45 kN T6
Wrought T6
150 200 250 300 350 400 450
Proof strength (MPa)
7
8
9
10
11
12
13
Elo
ng
atio
n(%
)
Single
Single T6
15 kN
30 kN
45 kN
45 kN T6
Wrought T6
As depositedHeat treated
ST+AA
Rolled + heat treatedST+AA
There is noporosity of therolled + heattreatedsample.
Rolling + heat treatmentporosity
Aluminium properties (2024 – 2319– 5087 (average))
100 150 200 250 300 350 400 450
Proof strength (MPa)
200
250
300
350
400
450
500
550
600
Ultim
ate
ten
sile
str
en
gth
(MP
a)
100 150 200 250 300 350 400 450
Proof strength (MPa)
6
8
10
12
14
16
18
20
22
Elo
ng
ation
(%)
-1750
250
2250
4250
6250
8250
10250
0 50 100
Distancefrom
Substrate[μm]
Composition [wt%]
Mo
Ta
W
Mo
Ta
W
-1750
750
3250
5750
8250
0 300 600
Distancefrom
Substrate[μm]
Vickers Hardness [HV]
Graded Structure Ta/Mo/W(Chemical Analysis and Hardness)
Mixed materials - copper and steel+ WC
Yield 140 MPa, UTS 300 MPa,elongation 12%, failure in bronze
Steel/bronze (CuSi3%) partsCopper on steel with WC ceramic
added
Future Developments
• Commercial WAAM systems - both CNC and robotic
• Control and toolpath planning software to drive them
• Very large scale systems
• Parallel process systems (multi deposition, on-line NDT/metrology)
Summary
• WAAM is an excellent process for large scale additive manufacture of awide range of materials
• Mechanical properties are excellent
• With cold work mechanical properties cam exceed those of forgedmaterials
WAAMMat website
WAAMMat website www.waammat.com
CONTACT: Prof Stewart Williams [email protected]
THANK YOU FOR YOURATTENTION - ANY
QUESTIONS ☺