Novel Ultra-High Straining Process for Bulk Materials— Development of the Accumulative Roll-Bonding (ARB) Process Authored by Y. Saito, H. Utsunomiya,

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 ReeveSeptember 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, 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 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, tn, n, ε, rt

For reduction of 50% in a pass Thickness after n cycles

t = t0 / 2n

Total reduction after n cycles rt = 1 – t / t0 = 1 – 1 / 2n

Equivalent plastic strain

nn 80.0)}2

1ln(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

ResultsMaterial # 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???