Novel Ultra-High Straining Process for Bulk Materials ...

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29 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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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


Introduction


Model


Design Application


Experimental Procedure


Results


Conclusion


Questions

Introduction


Why is Accumulative Roll
-
Bonding important?


Ultra
-
fine grain materials exhibit desirable
properties


High strength at ambient temperatures


High
-
speed superplastic deformation at elevated
temperatures


High corrosion resistance


Commonly accomplished by intense plastic
straining

Introduction


Processes used such as cyclic extrusion
compression have two main drawbacks


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


References:


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
, 9
th

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


Principle


Rolling bond surfaces together


Refines microstructure


Improves properties.


Iterative process


Process design steps


Surface treatment


Stacking


Roll bonding (heating)


Cutting

Model


Important parameters: t, t
n
, n, ε, r
t


For reduction of 50% in a pass


Thickness after n cycles


t = t
0

/ 2
n


Total reduction after n cycles


r
t

= 1


t / t
0

= 1


1 / 2
n


Equivalent plastic strain





n
n
80
.
0
)}
2
1
ln(
3
2
{




Design Application

Experimental Procedure


No “special” equipment needed!


Three alloys chosen


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)

Roll
speed
(m/min)

Mean
Strain
Rate (/s)

Al (1100)

473 K x 5
min

225

10

12

Al (5083)

473 K x 5
min

310

43

46

IF Steel

773 K x 5
min

310

43

46

Results

Results


Expected that grain refinement:


Improves mechanical properties related to
strength


Decreased % elongation in direction of roll
-
bonding


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


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???