摘要(英) |
The 3003 aluminum alloy which contains Mn, Fe and Si as alloying elements is widely used in the container, packaging, and automobile industry, because of its excellent specific strength, corrosion resistance and formability. During solidification, most of the Mn atoms can be solid-dissolved in the aluminum matrix, which results in a supersaturated solid solution. This supersaturated solid solution decomposes via the precipitation of dispersed particles during the homogenization treatment prior to hot rolling or extrusion. Therefore, controlling the size, density and distribution of the precipitated particles, as well as quantity of Mn atoms in the solid solution during homogenization are very important. First, we study evolution of precipitation during different homogenization treatments in a 3003 aluminum alloy. The evolution of the precipitation of second phase particles dispersed in a DC cast 3003 aluminum alloy during different homogenization treatments was investigated. Eight kinds of homogenization conditions were designed. We conclude that the evolution of precipitated dispersed particles during homogenization is controlled by nucleation, growth, Ostwald ripening process and hetero-precipitation. Nucleation of the particles would occur first during the initial phase of homogenization. They would then undergo a process of growth, dissolution and coarsening, before reaching the final state of precipitation. Two-color particles usually appear at step-homogenization, which has a lower later temperature, 600℃x9h?460℃x3h, due to a hetero-precipitation behavior.
The mechanical properties of extrusion products are mainly determined by the final result of the extrusion recrystallization. Following the priority study, we used the four conditions which had the largest difference between the precipitation and the solution quantity in the eight designed conditions to study evolutionary behavior of recrystallization during the extrusion of Al-Mn alloys. The different solution quantities and precipitation states in a homogenized Al-Mn alloy, and the effects of these on recrystallization behavior during extrusion were investigated. Homogenization at a low temperature of 460℃ resulted in a plentiful precipitation, which acted to pin down dislocations, thus making the recrystallization more difficult. At a higher homogenization temperature of 600℃, the particles were more sparsely dispersed, causing a weaker obstruction effect and making recrystallization easier. There were almost no dispersed precipitates at the highest homogenization temperature of 630℃, but dislocations were held up by abundant solution atoms, causing weaker recrystallization than that at 600℃. Although the solution quantity was much less under step-homogenization (600℃x9h?460℃x3h) than that under the 600℃x9h condition, the recrystallization situation was very similar. Finally, the recrystallization could be distinguished as elongated grains or equi-axial grains.
The tubes of the automobile fin-tube heat exchangers are usually produced by extruding 3003 aluminum alloys, and are then combined with fins via brazing bonds at 600℃ for 10 minutes. In this high temperature, the extrusion recrystallization will change, and affect the final mechanical properties of the products. Therefore, the study of extrusion forming ability and brazing properties in 3003 aluminum alloys is very significant. We used the four conditions which had the better forming ability in the priority eight designed conditions to do this investigation. The effects of precipitation in homogenization treatments, recrystallization in extrusion and brazing on extrusion forming ability and final material properties are examined. At first, fine dispersoids were precipitated during the 460℃x9h homogenization treatment and coarse dispersoids were precipitated by homogenization treatments with 600℃x9h. Second, when the dispersoids were not plentiful and fine enough during extrusion, the amount of solution dominated the extrusion breakout pressure, and recrystallization was easier; on the contrary, the domination state was replaced by plentiful and fine dispersoids, and recrystallization became more difficult. Additionally, the hardness after extrusion was lower in the complete recrystallization position, and higher in the incomplete recrystallization position. Finally, in brazing, the sample under the 460℃x9h condition underwent full recrystallization with a reduction in strength; the local position of the edge of the sample under the 600℃x9h?460℃x3h condition exhibited a second recrystallization and a significant drop in hardness.
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參考文獻 |
[1] T. Doko, S. Asami, K. Yagi: The Japan Institute of Light Metals 1988; 38: 393-386.
Effects of precipitate particles on structure evolution during hot rolling of 3003 aluminum alloy.
[2] S. Asami, T. Doko, K. Yagi: The Japan Institute of Light Metals 1989; 39: 100-94.
Recrystallization behavior during hot rolling of 3004 aluminum alloy.
[3] P. Furrer, G. Hausch: Metals Science 1979; 13: 162-155.
Recrystallization Behavior of Commercial Al--1% Mn Alloy.
[4] R.K. Bolingbroke, G.J. Marshall, R.A. Ricks: The 3rd International Conference on Aluminum Alloys 1992; pp290-285.
Microstructural development during preheating of AA3004.
[5] E. Nes: Acta Metallurgica 1976; 24: 398-391.
Effect of a fine particle dispersion on heterogeneous recrystallization.
[6] F.J. Humphreys: Acta Metall 1977; 25: 1344-1323.
Nucleation of recrystallization at second phase particles in deformed aluminium.
[7] G. Hausch, P. Furrer, H. Warlimont: Z Metallkd 1978; 69: 181-174.
Recrystallization and precipitation in Al-Mn-Si-alloys.
[8] Y. Kwag, J.G. Morris: Materials Science and Engineering 1986; 77: 74-59.
The effect of structure on the mechanical behavior and stretch formability of constitutionally dynamic 3000 series aluminum alloys.
[9] W.B. Hutchinson, A. Oscarsson, A. Karlsson: Materials Science Technology 1989; 5: 1127-1118.
Control of microstructure and earing behaviour in aluminium alloy AA 3004 hot bands.
[10] Y.J. Li, L. Arnberg: Materials Science and Engineering A 2003; 347: 135-130.
Evolution of eutectic intermetallic particles in DC-cast AA3003 alloy during heating and homogenization.
[11] Y.J. Li, L. Arnberg: Acta Materialia 2003; 51: 3428-3415.
Quantitative study on the precipitation behavior of dispersoids in DC-cast AA3003 alloy during heating and homogenization.
[12] P.C.M. de Haan, J. van Rijkom, J.A.H. Sontgerath: Materials Science Forum 1996; 765: 222-217.
[13] G. Lang, A.F. Castle et al.:“Extrusion” 1982, Scientific and Technical Development, Deutshe Gesellshaft fur Metallkunde.
[14] W.D. Finkelnburg, G. Scharf: ET’92 1992; 2, 475.
[15] T. Sheppard: Proceedings of Third International Aluminum
Extrusion Technology Seminar 1984; pp124-107.
[16] W. Libura: Proceedings of Fifth International Aluminum
Extrusion Technology Seminar 1992; 2, 494-485.
[17] T. Sheppard, A. Jackson: Proceedings of the Sixth International Aluminum Extrusion Technology Seminar 1996; 1, 228-223.
[18] K. Aschroft, G.S. Lawson: The Japan Institute of Metals 1961; 89, 369.
[19] E. Siebel: Chapman&Hall 1960; pp201.
[20] W. Misiolek: Light Metal Age 1988; pp22-18.
[21] L. Martin, R. Oddvin: Proceedings of the Sixth International Aluminum Extrusion Technology Seminar 1996; 1, 21-11.
[22] S. Okaniwa: The Japan Institute of Light Metals 1995; 45, 489-471.
[23] A.K. Vasudevan, R.D. Doherty: Aluminum Alloys Contemporary Research and Applications, Academic Press, Inc., San Diego 1989; pp170-35.
[24] M.P. Clode: Proceedings of Sixth International Aluminum Extrusion Technology Seminar 1992; 2, 79.
[25] T. Sheppard: Metal Technology 1981; pp130.
[26] R.D. Doherty: Metal Science 1982; 16, pp.13-1.
[27] H.M. Chan, F.J. Humphreys: Metal Science 1984; 18, 529-527.
[28] H.M. Chan, F.J. Humphreys: Acta Metallurgica 1984; 32, 243-235.
[29] R.E. Reed-Hill, R. Abbaschian: Physical Metallurgy Principles, 3rd ed., Boston, PWS Publishing Company 1991, pp535-515.
[30] D. Williamand, Jr. Callister: Materials Science and Engineering, 3rd ed., New York, John Wiley & Sons, Inc 1994; pp162-92.
[31] D.A. Porter, K.E. Easterling: Phase Transformations in Metals and Alloys, London, Chapman & Hall 1993; pp47-44, pp75-71, pp317-314.
[32] N. Adler, R. Deiasi and G. Geschwind: Materials Transactions 1972; 3, 3200-3191.
[33] R.E. Reed-Hill, R. Abbaschian: Physical Metallurgy Principles, 3rd ed., Boston, PWS Publishing Company 1991, pp46-461.
[34] J.E. Hatch: Aluminum-Properties and Physical Metallurgy, ASM, Metals Park, Ohio 1984; pp104-58, pp197-134.
[35] G. Itoh, H. Saitoh, B.L. Ou, H. Suzuki: The Japan Institute of Light Metals 1986, 36, 490-485.
[36] H. Watanabe, K. Ohori, Y. Takeuchi: The Japan Institute of Light Metals 1982; 33: 156-149.
Phase change in 3004 base alloys at elevated temperatures.
[37] A.L. Dons: Scandinavian Journal of Metallurgy 1984; 13: 148-137.
Variations in the composition of AlMnFeSi-particles in aluminum
[38] J. Sanders, D.J. Lege, T.L. Hartman: Aluminum 1989; 65: 950-941.
Aluminum Rigid Container for the Packaging Industry.
[39] R.G. Kamat: JOM 1996; 48: 45-34.
AA3014 can-body stock ingot:characterization and homogenization.
[40] Z. Li, J.G. Morris, S.X. Ding, C.X. Li: The 3rd International Conference on Aluminum Alloys 1992; 378-373.
Effect of homogenization on recrystallization behavior of AA 3004 aluminum.
[41] J. Kaneko, M. Sugamata, M. Takeshima: The Japan Institute of Light Metals 1985; 35: 20-12.
Effects of tempering on the formability of 3003 and 3004 aluminum sheets.
[42] T. Inaba, E. Usui, N. Shinano: The Japan Institute of Light Metals 1989; 39: 7-3.
Age-hardening behavior of Al-1%Mn-1%Mg alloy.
[43] T. Inaba, E. Usui: R-D Kobe Steel Engineering 1991; 41: 81-77.
Effects of heat treatment on Formability of 3004 alloy sheets.
[44] E. Nes, S.E. Naess, R.Z. Hoier: Z Metallkd 1972; 63: 256-248.
Decomposition of an Aluminum-Manganese Alloy.
[45] P. Furrer: Z Metallkd 1979; 70: 708-699.
Structural Changes in the Heat Treatment of Continuously Cast Al-Mn Ingots.
[46] F.S. Lameiras: Journal of Materials Research 1999; 2: 143-139.
Ostwald Ripening:An approach with dynamical system.
[47] F. Despa, M. Apostol: Journal of Theoretical Physics 1999; 40: 5-1.
On the Ostwald Ripening process.
[48] T. Minoda, H. Yoshida: Sumitomo Light Metal Technical Reports 1998; 39, 25-20.
[49] H.D. Merchant: Metals Society 1988; pp117.
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