采用显微硬度测试、差示扫描量热法(DSC)和透射电镜(TEM)测试研究高温预变形工艺对 Al?Mg?Si 合金自然时效和烘烤硬化的影响。结果表明：合金固溶处理后立即进行170°C 预变形可以有效降低常温预变形工艺的T4态硬度过高等有害作用，并产生更好的烘烤硬化效果。170°C 预变形7%并保持10 min 是最佳的高温预变形工艺，可以使合金获得较低的 T4态硬度和良好的烘烤硬化效应。高温预变形过程中同时产生的位错和 Cluster(2)可以显著地抑制合金的自然时效，并促进烤漆过程中β″相的析出，同时产生的动态回复可以有效抑制加工硬化产生的不利影响。
The influences of high temperature pre-straining (HT-PS) on the natural aging and bake hardening of Al?Mg?Si alloys were investigated by Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterization. The results show that pre-straining at 170 °C immediately after quenching can effectively resolve the rather high T4 temper hardness caused by the conventional room temperature (RT) pre-straining treatment, and give a better bake hardening response (BHR) after paint-bake cycle. HT-PS 7% at 170 °C for 10 min is chosen as the optimum process as it provides lower T4 temper hardness and better BHR. The simultaneous introduction of dislocations and Cluster (2) can significantly suppress the natural aging and promote the precipitation of β″ phase, and reduce the effects of deformation hardening by dynamic recovery.
参考文献
| [1] | G.A.Edwards;K.Stiller;G.L.Dunlop.The precipitation sequence in Al-Mg-Si alloys[J].Acta materialia,199811(11):3893-3904. |
| [2] | CALIN D. MARIOARA;SIGMUND J. ANDERSEN;JOSTEIN ROYSET.Improving Thermal Stability in Cu-Containing Al-Mg-Si Alloys by Precipitate Optimization[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,20147(7):2938-2949. |
| [3] | Cao, L.;Rometsch, P.A.;Couper, M.J..Clustering behaviour in an Al-Mg-Si-Cu alloy during natural ageing and subsequent under-ageing[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2013:257-261. |
| [4] | F.A. Martinsen;F.J.H. Ehlers;M. Torsaeter.Reversal of the negative natural aging effect in Al-Mg-Si alloys[J].Acta materialia,201217(17):6091-6101. |
| [5] | Y. Birol;M. Karlik.Bake hardening of twin roll cast Al-Mg-Si sheet[J].Materials Science and Technology: MST: A publication of the Institute of Metals,20052(2):153-158. |
| [6] | Yucel Birol.Pre-Straining to Improve the Bake Hardening Response of a Twin-Roll Cast Al-Mg-Si Alloy[J].Scripta materialia,20053(3):169-173. |
| [7] | De Geuser F;Lefebvre W;Blavette D.3D atom probe study of solute atoms clustering during natural ageing and pre-ageing of an Al-Mg-Si alloy[J].Philosophical Magazine Letters,20064(4):227-234. |
| [8] | Y. BIROL.Restoration of the Bake Hardening Response in a Naturally Aged Twin-Roll Cast AlMgSi Automotive Sheet[J].Scripta materialia,200612(12):2003-2008. |
| [9] | TAKESHI SAITO;RANDI HOLMESTAD;SHINJI MURAISH.The Effects of Low Cu Additions and Predeformation on the Precipitation in a 6060 Al-Mg-Si Alloy[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,20139(9):4124-4135. |
| [10] | Teichmann, K.;Marioara, C.D.;Andersen, S.J.;Pedersen, K.O.;Gulbrandsen-Dahl, S.;Kolar, M.;Holmestad, R.;Marthinsen, K..HRTEM study of the effect of deformation on the early precipitation behaviour in an AA6060 Al-Mg-Si alloy[J].Philosophical magazine: structure and properties of condensed matter,201128/30(28/30):3744-3754. |
| [11] | Engler, Olaf;Schaefer, Carmen;Myhr, Ole Runar.Effect of natural ageing and pre-straining on strength and anisotropy in aluminium alloy AA 6016[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2015:65-74. |
| [12] | Serizawa, A.;Sato, T.;Miller, M.K..Effect of cold rolling on the formation and distribution of nanoclusters during pre-aging in an Al-Mg-Si alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2013:492-497. |
| [13] | Michal KOLAR;Ketill Olav PEDERSEN;Sverre GULBRANDSEN-DAHL;Knut MARTHINSEN.预变形结合人工时效对Al-Mg-Si合金力学性能的影响[J].中国有色金属学报（英文版）,2012(08):1824-1830. |
| [14] | C.D. Marioara;S.J. Andersen;H.W. Zandbergen.The Influence of Alloy Composition on Precipitates of the Al-Mg-Si System[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,20053a(3a):691-702. |
| [15] | Y. Birol.Pre-aging to improve bake hardening in a twin-roll cast Al-Mg-Si alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,20051/2(1/2):175-180. |
| [16] | Wenchao Yang;Mingpu Wang;Xiaofei Sheng.Precipitate characteristics and selected area diffraction patterns of the ?' and Q' precipitates in Al-Mg-Si-Cu alloys[J].Philosophical Magazine Letters,20111/2(1/2):150-160. |
| [17] | S.J.Andersen;H.W.Zandbergen;J.Jansen.The crystal structure of the β" phase in Al-Mg-Si alloys[J].Acta materialia,19989(9):3283-3298. |
| [18] | A. SERIZAWA;S. HIROSAWA;T. SATO.Three-Dimensional Atom Probe Characterization of Nanoclusters Responsible for Multistep Aging Behavior of an Al-Mg-Si Alloy[J].Metallurgical and materials transactions. A, physical metallurgy and materials science,20082(2):243-251. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%