acceptable peak temperature and thermal stress in ti6al4v … · 2018. 11. 22. · 2 ms, 100 hz #4:...
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Acceptable Peak Temperature and Thermal Stressin Ti6Al4V Target of ILC Positron Source
A. Ushakov1, S. Riemann2 and G. Moortgat-Pick1
1University of Hamburg, 2DESY
POSIPOL Workshop, CERN
3 September 2018
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 1 / 21
Outline
Deformation of Ti6Al4V targets by 14 MeV e− pulsed beam of theMainz Microtron
Stress-strain curves of Ti-alloy (Grade 5) at elevated temperatures
Plastic flow simulations in ANSYS above yield point (yieldstrength)
Allowed thermal stress at different temperatures
Summary
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 2 / 21
Targets and Used MAMI Electron Beam (March 2016)
#1: 1 mm thicknesswo thermal contact to holder
#2: 1 mm thicknesswith thermal contact to holder
#3: 2 mm thicknesswo thermal contact to holder
#4: not used
2 ms pulses, 100 Hz~18.5h of irradation
3 ms pulses, 67 Hz~4h of irradation
2 ms pulses, 100 Hz~14.5h of irradation
Electron beam for all targets:14 MeV, 50 µA during pulse, σ = 180 µm
Targets
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 3 / 21
Energy Deposition and Average Heating Power
Energy Deposition by Beam(FLUKA)
Average Heating PowerImported in ANSYS
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 4 / 21
Average Temperature vs Emissivity1 mm Target, 50 µA, 2 ms, 100 Hz
Temperature was measured by thermocouple at ≈ 5 mm distance from middle of thebeam.After switching beam on Tmeasured has achieved saturation level at T = 381◦C after6 min of irradiation.
Temperature vs Emissivity
0,5 0,6 0,7 0,8
400
450
500
550
600
650
T [°
C]
Emissivity
Tmeasured
Tmax
Temperature vs Time (ε = 0.7)
0 50 100 150 200 250 3000
100
200
300
400
500
600
T [°
C]
t [s]
Tmax
Tmeasured
Tmin
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 5 / 21
Peak Average Temperature of Different Targets
#1: 1 mm thick, therm. isolated
2 ms, 100 Hz
#2: 1 mm thick, with th. contact
3 ms, 67 Hz
#3: 2 mm thick, therm. isolated
2 ms, 100 Hz
#4: not used
Peak Average Temperature vs Time
0 50 100 150 200 250 3000
100
200
300
400
500
600
700
T [°
C]
t [s]
1 mm thickness, isolated 1 mm thickness, with contact 2 mm thickness, isolated
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 6 / 21
Deformation of Targets
No visible deformation
on back side of target 1
No visible deformation
on both sides of target 21mm
Target 1: front side
Target 3: front side
500�m
Target 3: back side
Peak hight: ~15 µm1mm
(front side)
Can ANSYS be used for the prediction of target deformation?
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 7 / 21
Thermal Cycles and Temperature Distributions2 mm Target, 50 µA, 2 ms, 100 Hz, ε = 0.7
At End of Thermal Cycle At End of Pulse
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 8 / 21
Data on Stress-Strain Curves
0
40
80
120
160
200
240
280
0 4 8 12 16 20
Strain, 0.001 in./in.
Str
es
s,
ksi
RT
700 °F
400 °F
-423 °F
-321 °F
-110 °F
900 °F
MIL-HDBK-5H
1 December 1998
M. Kopec et al., DOI:10.1016/j.msea.2018.02.038
[MIL-HDBK-5H]: Military Handbook “Metallic materials and elements for aerospace vehiclestructures”, MIL-HDBK-5H, 1 December 1998, 1651 pp.
[Kopec]: M. Kopec et al., Materials Science and Engineering A 719 (2018) 72-81
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 9 / 21
Young’s Modulus
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 10 / 21
Multilinear Hardening
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 11 / 21
Coefficient of Thermal Expansion (MILHDBK5H)
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 12 / 21
Thermal “Cycle” Starting at 375◦C
0,000 0,005 0,010 0,015 0,0200
1x108
2x108
3x108
4x108
5x108
Eq. v
M S
tress
[Pa]
Eq. Total Strain [m/m]
375°C
1061°C
T"average" = 718°C
Highest equivalent von Mises stress in elastic region is 303 MPa
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 13 / 21
Distribution of Equivalent Stress
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 14 / 21
Thermal “Cycle” Starting at 548◦C
0,000 0,001 0,002 0,003 0,004 0,0050,0
4,0x107
8,0x107
1,2x108
1,6x108
2,0x108
2,4x108
Eq. v
M S
tress
[Pa]
Eq. Total Strain [m/m]
T"average" = 813°C
Highest equivalent von Mises stress in elastic region is 189 MPa
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 15 / 21
Thermal “Cycle” Starting at 717◦C
0,000 0,001 0,002 0,003 0,004 0,0050,0
4,0x107
8,0x107
1,2x108
1,6x108
Eq. v
M S
tress
[Pa]
Eq. Total Strain [m/m]
T"average" = 921°C
Highest equivalent von Mises stress in elastic region is 123 MPa
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 16 / 21
Maximum Allowed Thermal Stress and PEDD inTi6Al4V at Elevated Temperatures
Yield Strength and Max. ElasticEq. von Mises Stress vs Temperature
0 200 400 600 800 10000
200
400
600
800
[MIL-HDBK-5H,Kopec-2018]
(ANSYS Calculations)Max Equivalent von Mises Stress
Stre
ss [M
Pa]
Temperature [°C]
Yield Strength
Maximal PEDD vs Temperature
600 700 800 900 1000
240
280
320
360
400
440
480
520
PED
D [J
/(g p
ulse
)]
Average Temperature [°C]
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 17 / 21
Summary
Adding temperature dependent elasticity and hardening data to thematerial properties in ANSYS allows making estimations of temperatureand stress at which material starts to deform plastically.
Simulations have shown that the maximum equivalent stress ofelastically deformed by beam Ti6Al4V target is approx. 10% below theyield strength.
Transition from elastic to plastic deformation occurs at 600◦C averagetemperature when the equivalent von Mises stress reaches 400 MPa.
At higher temperatures the limits go down quickly, for example, at 800◦Caverage temperature: equivalent stress has to be < 200 MPa.
Further studies are needed to include impact of radiation damage andweakening of material caused by repeatedly applied loads (fatigue).
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 18 / 21
Many thanks to all people involved in "Target Experiments"
University Hamburg and DESYAlexander IgnatenkoGudrid Moortgat-Pick
Alena PrudnikavaSabine Riemann
University MainzKurt AulenbacherThomas Beiser
Philipp HeilValery Tyukin
Helmholtz Zentrum BerlinYegor Tamashevich
CFEL, HamburgAlexander KotheThorsten Uphues
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 19 / 21
Specific Heat
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 20 / 21
Transverse Beam Size
100 150 200 2500
5
10
15
20
25
30250 µm aperture radius
I targ
et [%
]
beam [µm]
0.06nA/0.36nA
A. Ushakov (University of Hamburg) Temperature and Stress in Ti6Al4V Target POSIPOL, 3 September 2018 21 / 21