采用自孕育法制备A356铝合金半固态浆料,研究薄壁件流变压铸过程中的凝固行为.结果表明:在自孕育制浆过程中,等温保温过程对初生α(Al)颗粒的尺寸和形貌影响较大,而对后续薄壁件压铸过程中的二次凝固组织影响不是很大.当剩余液相充填型腔时,型腔提供的较大冷却速率使剩余液相爆发形核;晶核的生长分为稳定生长和失稳生长两个过程.爆发形核的核心先稳定生长成球状小颗粒,稳定生长的极限尺寸为6.5 μm.由于“成分过冷”等因素的存在,一次凝固(α1)颗粒和二次凝固(α2)颗粒最终均出现不稳定生长现象.由于α1颗粒的存在,剩余液相的成分与原始成分相比更接近共晶成分,导致α2颗粒中Si的含量较α1颗粒中的高.α2颗粒将共晶反应限制在许多晶间小区域内,在较高的局部冷却速率下,共晶硅最终长成细小纤维状或菊花状.
参考文献
| [1] | 罗守靖;姜永正;李远发;单巍巍.重新认识“半固态金属加工技术”[J].特种铸造及有色合金,2012(7):603-607. |
| [2] | D. G. Eskin;Suyitno;L. Katgerman.Mechanical properties in the semi-solid state and hot tearing of aluminium alloys[J].Progress in materials science,20045(5):629-711. |
| [3] | 徐骏;张志峰.半固态加工技术的最新进展[J].哈尔滨理工大学学报,2013(2):1-6. |
| [4] | H. Kaufmann;A. Mundl;R. Potzinger;P. J. Uggowitzer;N. Ishibashi.An update on the new rheocasting - development work for Al- and Mg-alloys[J].Die Casting Engineer,20024(4):16-19. |
| [5] | Stephen P. Midson.Rheocasting Processes for Semi-Solid Casting of Aluminum Alloys[J].Die Casting Engineer,20061(1):48-51. |
| [6] | 李元东;杨建;马颖;曲俊峰;张鹏.浇注温度对自孕育铸造法制备AM60镁合金半固态浆料的影响（Ⅰ）[J].中国有色金属学报,2010(6):1046-1052. |
| [7] | Hitchcock M;Wang Y;Fan Z.Secondary solidification behaviour of the Al-Si-Mg alloy prepared by the rheo-diecasting process[J].Acta materialia,20075(5):1589-1598. |
| [8] | 李元东;陈体军;马颖;阎峰云;郝远.触变成形AZ91D镁合金的组织与二次凝固行为[J].中国有色金属学报,2008(1):18-23. |
| [9] | Zhongwei Chen;Hailing Zhang;Yimin Lei.Secondary Solidification Behaviour of AA8006 Alloy Prepared by Suction Casting[J].材料科学技术学报：英文版,2011(09):769-775. |
| [10] | 李元东;刘兴海;李艳磊;索江龙;周宏伟;张心龙.2024变形铝合金半固态浆料在连续冷却和保温过程中的组织演变[J].中国有色金属学报,2013(11):3015-3023. |
| [11] | 邢博;郝远;李元东;马颖;陈体军.自孕育法制备AZ31镁合金半固态流变成形组织[J].中国有色金属学报（英文版）,2013(3):567-575. |
| [12] | 李元东;邢博;马颖;郝远.导流器对自孕育铸造法制备AM60镁合金半固态浆料的影响（Ⅲ）[J].中国有色金属学报,2012(1):22-32. |
| [13] | Li Yanlei;Li Yuandong;Li Chun;Wu Huihui.Microstructure characteristics and solidification behavior of wrought aluminum alloy 2024 rheo-diecast with self-inoculation method[J].中国铸造,2012(04):328-336. |
| [14] | E.D. Manson-Whitton;I.C. Stone;J.R. Jones.Isothermal grain coarsening of spray formed alloys in the semi-solid state[J].Acta materialia,200210(10):2517-2535. |
| [15] | Waterloo G.;Jones H..MICROSTRUCTURE AND THERMAL STABILITY OF MELT-SPUN AL-ND AND AL-CE ALLOY RIBBONS[J].Journal of Materials Science,19969(9):2301-2310. |
| [16] | 郭志鹏;熊守美;曺尚铉;崔正吉.合金材料以及工艺参数对压铸过程中铸件/铸型界面换热系数的影响[J].金属学报,2008(4):433-439. |
| [17] | Hunt J.D.;Lu S.Z..Numerical Modeling of Cellular/Dendritic Array Growth: Spacing and Structure Predictions[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,19963(3):611-623. |
| [18] | W. Yang;F. Liu;H.F. Wang.Non-equilibrium transformation kinetics and primary grain size distribution in the rapid solidification of Fe-B hypereutectic alloy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,20116(6):2903-2908. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%