SSM PROCESSING R&D: PROGRESS REPORT - Badger Metal · Research Portfolio: DOE -Funded SSM...
Transcript of SSM PROCESSING R&D: PROGRESS REPORT - Badger Metal · Research Portfolio: DOE -Funded SSM...
SSM PROCESSING R&D:
PROGRESS REPORTD. Apelian and M. Makhlouf
www.wpi.edu/+mpiNADCA R&D Committee Meeting
October 16, 2002
ACRC Consortium Members
September 2002
• Alcan International Ltd.
• Aluminum Company of America
• Aluminum Pechiney
• Amcast Industrial Corp.
• BMW AG
• Briggs & Stratton Corp.
• Buhler Inc.
• Chem-Trend Inc.
• Citation Corp.
• Consolidated Metco
• Daimler Chrysler Corp.
• Elkem Aluminum ANS
• Ford Motor Co.
• J. L. French International Ltd.
• General Aluminum Manufacturing Co.
• General Motors Corp.
• Harley-Davidson Motor Co.
• Hayes Lemmerz International, Inc.
• Heraeus Electro-Nite Co.
• Hitchcock Industries, Inc.
• Hydro Aluminum A.S.(VAW- Hydro Germany)
• IdraPrince Corp.
• Intermet Corp.
• Kennedy Die Castings, Inc.
• Leggett & Platt Aluminum Group
• Madison-Kipp Corp.
• Mercury Marine
• Metallurg Aluminum
• Montupet
• NEMAK
• North American Die Casting (NADCA)
• Ormet/Formcast, Inc.
• Palmer Foundry, Inc.
• Phillips Plastics
• Salzburger Aluminum AG
• Selee Corp.
• SPX Corp.
• Superior Industries International, Inc.
• Teksid Aluminum S.p.A.
• THT Presses
• TRW Automotive
• Visteon Chassis Systems
Semi-Solid Processing Studies
Projects Completed (1998 – 2001)
1. Yield Stress Measurements and Quantitative Microstructure Characterization (WPI)
2. Modeling of Rheology in Semi-Solid Alloys (WPI)
3. Optimization of Heat Treatment Conditions for Semi-Solid 357 Alloy (WPI)
4. Time Dependent Rheology of Semi-Solid Alloys (MIT)
5. Microstructural Evolution in Semi-Solid Alloys (MIT)
6. Development of Alternate Semi-Solid Aluminum Alloys (ORNL)
Semi-Solid Processing Studies
Current SSM Projects Beginning January 2002
1. A Continuous Rheoconversion Process for Production of Semi-solid Slurries (WPI)
2. High-Temperature Rheological Measurements
3. AlB2 Grain Refined Billet Route - SiBloy™ (WPI)
4. Modeling and Prediction of SSM Rheology (WPI)
Yield Stress Measurements and Quantitative Microstructure Characterization
Q. Y. Pan and D. Apelian
DOE-Funded SSM Processing Projects
• Establish yield stress vs temperature relationship for commercial semi-solid Al alloys
• Understand how processing method affects slurry yielding behavior
• Quantitatively characterize microstructural evolution of various semi-solid billets during commercial forming conditions
• Investigate the effects of semi-solid structure on the rheological behavior of commercial semi-solid billets
Yield Stress vs. Temperature (A356)
SiBloy®
GR A356
UBE A356 MHD A356
570 575 580 585 590 595 T e m p e r a t u r e ( C )
0.1
1
10
100
1000
10000
Y i e l d S t r e s s ( k P a )
SiBloy®
GR A356
UBE A356 MHD A356
Yie
ld S
tres
s (k
Pa)
SiBloy®
GR A356
UBE A356 MHD A356
570 575 580 585 590 595 T e m p e r a t u r e ( C )
0.1
1
10
100
1000
10000
Y i e l d S t r e s s ( k P a )
SiBloy®
GR A356
UBE A356 MHD A356
Yie
ld S
tres
s (k
Pa)
540 550 560 570 580 590 600Temperature (C)
0.01
0.10
1.00
10.00
100.00
1000.00
10000.00Yi
eld
Str
ess
(kP
a)
1.45×10-3
1.45×10-2
1.45×103
1.45×102
1.45×101
1.45×100
1.45×10-1
Yield S
tress(psi)MHD 357
GR 357
Yield Stress vs. Temperature (357)
MHD A356 GR A356 SiBloy
MIT A356 SIMA A357 UBE (A356)
Semi-solid Microstructure at 580°C
Image Analysis ResultsEntrapped Liquid Content (Vf) vs. Temperature
575 580 585 590 595
Temperature (C)
0
10
20
30
40
Ent
rapp
ed L
iqui
d (%
)
0
10
20
30
40575 580 585 590 595
GR A356
SiBloy
SIMA A357
MHD A356 • Vf (GR)>> Vf(MHD)
• Vf(GR): 15-30%; Vf(SIMA): 11-14%Vf(MHD): 8-10%
• ↑T⇒ Vf↓
• Little entrapped liquid in MIT and UBE billets
Time (min.)
Liquidus
Solidus
Tem
pera
ture
(°C
)
Quench
Particle Size (Dp) vs. Temperature
• ↑T⇒ Dp ↑
• SIMA: 50-80 µm
• GR: 125-185µm
• No effect on SiBloy
575 580 585 590 595
Temperature (C)
40
80
120
160
200
Par
ticle
Siz
e (u
m)
40
80
120
160
200
575 580 585 590 595
GR A356SiBloy
MHD A356 UBE
SIMA A357MIT A356
Ave
rage
Par
ticle
Siz
e (µ
m)
Image Analysis Results
Shape Factor (SF) vs. Temperature
• ↑T⇒ SF↓
• SF=1⇒Spherical
• SIMA: 1.18-1.25
• SiBloy: 1.66-1.86
575 580 585 590 595
Temperature (C)
1
1.2
1.4
1.6
1.8
2
Sha
pe F
acto
r
1
1.2
1.4
1.6
1.8
2
GR A356
SiBloy
UBE
MIT A356
SIMA A357
MHD A356
Sha
pe F
acto
r (S
F)
Image Analysis Results
Modeling of SSM ProcessesAndreas Alexandrou
Objectives:
Research Portfolio: DOE-Funded SSM Processing Projects
•Perform numerical simulations of SSM mold filling operations anddevelop codes to predict and control mold filling instabilities
•Verify rheological models using experimental simulations
Flows in 2-D Expansions: Flow patterns and casting methods
0
20
40
60
80
100
120
140
160
180
200
0.01 0.1 1 10 100 1000 10000
bubble
mound
shell
disk
transition
τ 0 = 70000Pa
Bi
ReSQUEEZE CASTING
SEMISOLID CASTING
DIE CASTING
PistonPiston SemiSemi--solid solid aluminumaluminum Cavity
Mold
SSM Modeling: Flow Instabilities
Semisolid Aluminum Slurry: Flow Instabilities
Toothpaste Instability:experimental
Toothpaste Instability:FEM simulation results for(Re=1, Bi=3, L=10)
(Courtesy of Aluminum Pechiney)
(Courtesy of Aluminum Pechiney)
Time-Dependent Rheology of Semi-Solid Alloys (MIT)
A. Kato, A. M. de Figueredo, J. Yurko and M. C. Flemings
Research Portfolio: DOE-Funded SSM Processing Projects
Accomplishments
•Obtained fundamental rheological data on microstructural evolution of semi-solid Al alloys
•Determined effects of semi-solid slurry structure on flow at shear rates typical of forming processes
•Carried out experimental simulations of SSM flow
Research Portfolio: DOE-Funded SSM Processing Projects
Shear rate (1/s)
(parallel plate, compression)
(parallel plate, rotation)
• Agreement between experiments shows that complete break down of the slurry structure occurs in milliseconds
• Results show fully broken structures at shear rates below 1000 s-1
SSM Transient Behavior (Hysteresis) in Rotational and Compression Experiments
Research Portfolio: DOE-Funded SSM Processing Projects
• Rapid shear deformation of SSM slurries leads to large decreases in viscosity
• Viscosity recovery times are longer than typical mold cavity filling times
• Once the SSM structure is fully broken, the resulting slurry becomes very fluid and remains so for relatively long times
SSM Rheology: Transient Behavior in Rotational Experiments
Microstructural Evolution in Semi-Solid Alloys (MIT)
R. Martinez, A. M. de Figueredo, J. Yurko and M. C. Flemings
Research Portfolio: DOE-Funded SSM Processing Projects
Accomplishments
Developed a new method of forming semi-solid metal structures for slurry ready applications
Research Portfolio: DOE-Funded SSM Processing Projects
MIT New SSM Approach
Research Portfolio: DOE-Funded SSM Processing Projects
Typical semi-solid structures obtained in A357 alloys by coupling forced convection with rapid heat extraction just below the liquidus temperature.Primary aluminum particles do not contain entrapped eutectic.
Processed Alloy, As cast Re-heated to 585°C and quenched
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
A Continuous Rheoconversion Process (CRP) for Production of Semi-solid Slurries
M. Findon, A. M. de Figueredo, D. Apelian, and M. Makhlouf
Objective
Develop novel, economic methods of continuously forming semisolid metal slurries for rheocasting
and thixocasting applications
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
CRP - Continuous Rheoconversion Process
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
CRP - Continuous Rheoconversion Process
– Continuous conversion of liquid to slurry– Flexible
• Thixocasting or slurry-ready• Not alloy specific• Allows for rapid adjustment of solid content• Recycling of scrap easy to incorporate
– Can be used with one melt as well – design flexibility– Reasonable operating temperature range for slurry-
ready processing– Commercially viable – patent application submitted and
in process
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
CRP MICROSTRUCTURES: A356 ALLOYS
As-cast, TL=625°C Reheated to 585°C for 10min
and quenchedin water
As-cast, TL=660°C
High Temperature Rheological MeasurementsA. M. de Figueredo, Q. Y. Pan, and D. Apelian (WPI)
N. Tonmukayakul and Q. Dzuy Nguyen (University of Adelaide)
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
Objectives
• Investigate the flow behavior of semi-solid metals under transient flow conditions
• Determine shear stress-shear rate curves during rapid shear rate transients
• Correlate the viscosity of semi-solid metals with respective structures
• Develop instrumentation and techniques for rheological characterization of SSM slurries in the casting plant
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
Shear StressResponse
ViscosityResponse
Shear Rate Sweep
0.1
1
10
100
0 0.2 0.4 0.6 0.8 1
Time (s)
Viscosity-Up
Viscosity-Down
Shear Rate
590oC fs =0.39
39 vol%
0.1
1
10
100
0 300 600 900 1200
Shear Rate (1/s)
up
down
590oC fs =0.39
39 vol%
0
500
1000
1500
2000
0 300 600 900 1200
Shear Rate (1/s)
up
down
590oC fs =0.39
39 vol%
Response of SSM 357 Alloy to Rapid Shear
Deformation
Research Portfolio: DOE-Funded SSM Processing ProjectsStarted January, 2002
• A comprehensive program for the rheological characterization of SSM slurries has been established at MPI.
•This program is employing state of the art rheometry to characterize the flow behavior of SSM slurries under conditions of rapid deformation
Research Portfolio: DOE-Funded SSM Processing ProjectsStarting January, 2002
AlB2 Grain Refined SSM Billet Route
Objectives
Investigate microstructural refinement in casting aluminum alloys by addition of Si-B master alloy (SiBloy® technology), and develop economic processes for the production of high-quality SSM feedstock
580°C 582°C 585°C 590°C
580°C 582°C 585°C 590°C
SiBloy @ Billet Center
GR A356 @ Billet Center
Semi-solid Microstructures of SiBloy and GR A356 billets
Quantitative Data
576 580 584 588 592
Temperature (C)
0
4
8
12
Ent
rapp
ed L
iqui
d (%
)
0
4
8
12
A356
SiBloy
Time (min.)
Liquidus
Solidus
Tem
pera
ture
(°C
)
Quench
576 580 584 588 592
Temperature (C)
0
4
8
12
16
Ent
rapp
ed L
iqui
d (%
)
0
4
8
12
16
A356SiBloy
Billet Center Billet Edge
Quantitative Data
576 580 584 588 592
Temperature (C)
80
120
160
200
Par
ticle
Siz
e (u
m)
80
120
160
200A356
SiBloy
576 580 584 588 592
Temperature (C)
80
120
160
Par
ticle
Siz
e (u
m)
80
120
160A356
SiBloy
Billet Center Billet Edge
576 580 584 588 592
Temperature (C)
0.8
1.2
1.6
2
Sha
pe F
acto
r
0.8
1.2
1.6
2
A356
SiBloy
576 580 584 588 592
Temperature (C)
0.8
1.2
1.6
2
Sha
pe F
acto
r
0.8
1.2
1.6
2
A356
SiBloy
Quantitative Data
Billet Center Billet Edge
YS Measurement Results
570 575 580 585 590 595
Temperature (C)
0.1
1
10
100
1000
10000Y
ield
Str
ess
(kP
a)
0.1
1
10
100
1000
10000
GR A356
Unmodified SiBloy
Modified SiBloy
Yield stress vs. temperature
Research Portfolio: DOE-Funded SSM Processing ProjectsStarting January, 2002
Modeling and Prediction of SSM Rheology
A. Alexandrou and Q.Y.Pan
Objectives
Develop simulation tools to understand and control SSM flow instabilities in mold filing operations
Constant Shear RateTemp.: 585°CHeating rate: 49°C/min.Shear Rate: 5x10-3s-1; 8.33x10-3s-1
Constant Shear Force
MethodologyV
Temp.: 585°CHeating rate: 49°C/min.Shear Force: 2N; 4N
F
Time (min.)
Liquidus
Solidus
Tem
pera
ture
(°C
)
585°C
Apparatus
∆T: ≤ 1°C
LR: 0.001N
Flow Behavior of SSM A356 at Different Shear Strains
Experiment Simulation
(T: 585°C; shear rate: 5.0×10-3s-1; Shear Strains: 0, 19.5, and 31.9)
1 .0 1
1.01
1
1
1.01
0.99
0.99
R0 0.25 0.5 0.75 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
ZStagnantZone
Stagnant zone
Stagnant zone
Fluid Flow
Fluid Flow
Fluid Flow Fluid Flow
1. 01
1 .0 1
0 .99
0.99
1
1
R0 0.25 0.5 0.75 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
ZS tag nantZone
S tagnant zo ne
S tag nant zone
Fluid Flow
Fluid Flow
Fluid Flow
Stress Distribution under Compression
(Bi=5, Re=1, F=-1.)
Early Stage Late Stage
SSM processing of Hyper-eutectic Al-Si alloys
Deepak Saha, Babu Dasgupta* and D.Apelian* SPX Contech, MI, USA
Objectives
Processing of 390 alloy via the Rheo-casting (Slurry-on-Demand) route having a consistent and uniform distribution of primary Si
Research Portfolio: Industrial Internship Funded SSM Processing Projects
Conceptual Framework: Diffusion Solidification
12.6
% Si à
L1@ 760 0CAl-25% Si Alloy
L2+S@ 550 0CSibloyR (Fraction solid ~ 85 %)
Research Portfolio: Industrial Internship Funded SSM Processing Projects
Conceptual Framework
Control of uniformly distributed Si Phase is attained by heat balance
•Heat released
(Cooling from Liquid temperature to Liquidus + Latent Heat from the nucleating
and growing primary Si phase)
• Heat removal
(The mixing of the Eutectic liquid + Dissolution of Primary Al)
Heat Released = Heat Absorbed
Research Portfolio: Industrial Internship Funded SSM Processing Projects
Example: SibloyR at 550 0C mixed with 25% Al-Si at 760 0C (Final Temperature 590 0C)
Research Portfolio: Industrial Internship Funded SSM Processing Projects