Transcript Novel Ultra-High Straining Process for Bulk Materials— Development of the Accumulative Roll-Bonding

Novel Ultra-High Straining
Process for Bulk Materials—
Development of the
Accumulative Roll-Bonding
(ARB) Process
Authored by Y. Saito, H. Utsunomiya,
N. Tsuji, T. Sakai
Presented by Chris Reeve
September 13, 2004
Outline
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Introduction
Model
Design Application
Experimental Procedure
Results
Conclusion
Questions
Introduction
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Why is Accumulative Roll-Bonding important?
Ultra-fine grain materials exhibit desirable
properties
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High strength at ambient temperatures
High-speed superplastic deformation at elevated
temperatures
High corrosion resistance
Commonly accomplished by intense plastic
straining
Introduction
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Processes used such as cyclic extrusion
compression have two main drawbacks
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Requires large load capabilities, expensive
dies
Low production rate limits economic
viability
Function of paper is to introduce
Accumulative Roll-Bonding (ARB) as a
bulk manufacturing process
Introduction
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References:
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1. Richert, J. and Richert, M., Aluminum, 1986, 62, 604
2. Valiev, R. Z., Krasilnikov, N. A. and Tsenev, N. K., Mater. Sci. Engng, 1991,
A137, 35.
3. Horita, Z., Smith, D. J., Furukawa, M., Nemoto, M., Valiev, R. Z. and
Langdon, T. G., J. Mater. Res., 1996, 11, 1880.
4. Saito, Y., Utsunomiya, H., Tsuji, N. and Sakai, T., Japanese Patent applied
for.
5. Nicholas, M. G. and Milner, D. R., Br. Weld. J., 1961, 8, 375.
6. Helmi, A. and Alexander, J.M., J. Iron Steel Inst., 1968, 206, 1110.
7. Metals Handbook, 9th edn, Vol. 2. American Society for Metals, Metals
Park, OH, 1979, pp. 65-66.
8. Sakai, T., Saito, Y., Hirano, K. and Kato, K., Trans. ISIJ, 1988, 28, 1028.
9. Saito, Y., Tsuji, N., Utsunomiya, H., Sakai, T. and Hong, R. G., Scripta
mater., 1998, 39, 1221.
10. Tylecote, R. F., The Solid Phase Welding of Metals. Edward Arnold,
London, 1968.
Model
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Principle
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Rolling bond surfaces together
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Refines microstructure
Improves properties.
Iterative process
Process design steps
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Surface treatment
Stacking
Roll bonding (heating)
Cutting
Model
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Important parameters: t, tn, n, ε, rt
For reduction of 50% in a pass
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Thickness after n cycles
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Total reduction after n cycles
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t = t0 / 2n
rt = 1 – t / t0 = 1 – 1 / 2n
Equivalent plastic strain
2
1
  { ln( )}  n  0.80n
2
3
Design Application
Experimental Procedure
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No “special” equipment needed!
Three alloys chosen
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Al 1100 (commercially pure)
Al 5083 (Al-Mg alloy)
Ti-added interstitial free (IF) steel
Surfaces degreased, brushed
Strips were heated
50 % reduction rolling under dry
conditions
Experimental Procedure
Material
Heating
Roll
Diameter
(mm)
Al (1100) 473 K x 5 225
min
Roll
speed
(m/min)
10
Mean
Strain
Rate (/s)
12
Al (5083) 473 K x 5 310
min
43
46
IF Steel
43
46
773 K x 5 310
min
Results
Results
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Expected that grain refinement:
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Improves mechanical properties related to
strength
Decreased % elongation in direction of rollbonding
The number of cycles required to obtain
peak strength can only be determined
experimentally
Results
Material
# Cycles
TS (MPa)
% Elongation
Al (1100)
0 (Initial)
84
42
Al (1100)
8
304
8
Al-Mg (5083)
0 (Initial)
319
25
Al-Mg (5083)
7
551
6
IF Steel
0 (Initial)
274
57
IF Steel
5
751
6
Conclusions
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Practical industrial use for high strength
structural applications
Advances rolling technology by
application to a specific materials
processing method
Industries most impacted: construction,
marine, aerospace, automotive
Questions???