-
摘要: 通过Al、Si元素粉末的液相反应烧结制备了用于半固态成形的Al–6%Si（质量分数）合金坯料。研究结果表明，Al–6%Si混合粉末具有较好的冷压成形性能，经500 MPa冷压之后，其相对密度可达到97.6%。混合粉末的冷压压制特性可用黄培云压制方程进行描述。Al、Si元素粉末可以在585 ℃下发生反应生成液相，液相围绕等轴状的固相Al晶粒形成半固态组织。Al晶粒尺寸和液相含量随着反应时间的增加而增加。Al–6%Si元素粉末的反应烧结是一个液相持续存在的反应烧结系统，可以通过控制反应时间来控制半固态坯料的微观组织。
-
关键词:
- 液相反应烧结 /
- Al–Si合金半固态坯料 /
- 液相含量 /
- 等轴固相Al晶粒
Abstract: The Al–6%Si (mass fraction) semi-solid billets were prepared by liquid phase reaction sintering in this paper, using Al and Si elemental powders. In the results, the mixed Al–6%Si powders have the good cold pressing forming properties, and the relative density can reach 97.6% after 500 MPa cold pressing. The cold pressing characteristics of the mixed powders can be described by Huang Pei-yuan pressing equation. The Al and Si elemental powders can react to form the liquid phase at 585 ℃, which forms a semi-solid microstructure around the equiaxed solid phase Al grains. At the same time, the Al grain size and the liquid phase content of Al increase with the increase of reaction time. The reaction sintering of Al–6%Si elemental powders is a reaction sintering system with the continuous liquid phase, and the microstructure of the semi-solid billet can be controlled by controlling the reaction time. -
图 1 原始粉末和冷压素坯微观组织：（a）Al粉；（b）Si粉；（c）Al–6%Si混合粉末；（d）500 MPa冷压后素坯
Figure 1. SEM images of the initial powders and the green compacts: (a) Al powders; (b) Si powders; (c) Al–6%Si mixed powders; (d) green compacts prepared by cold pressing at 500 MPa
图 2 Al–6%Si混合粉相对密度与压制压力曲线（a）及黄培元压制方程拟合结果（b）
Figure 2. Relative density of the Al–6%Si mixed powders during cold pressing (a) and the fitting results of Huang Pei-yuan pressing equation (b)
图 3 经585 ℃液相反应烧结不同时间后半固态坯料微观组织：（a）10 min；（b）20 min；（c）40 min；（d）80 min
Figure 3. Microstructure of the semi-solid billets sintered at different times: (a) 10 min; (b) 20 min; (c) 40 min; (d) 80 min
图 4 初始粉末与半固态坯料的X射线衍射图谱
Figure 4. XRD patterns of the initial powders and the semi-solid billets
图 5 经585 ℃/10 min液相反应烧结制备的坯料背散射图和元素面分布图
Figure 5. BSE image and the element distribution maps of the billets prepared by LPS at 585 ℃ for 10 min
-
[1] Jung J G, Ahn T Y, Cho Y H, et al. Synergistic effect of ultrasonic melt treatment and fast cooling on the refinement of primary Si in a hypereutectic Al–Si alloy. Acta Mater, 2018, 144: 31 doi: 10.1016/j.actamat.2017.10.039 [2] Lasa L, Rodriguez-Ibabe J M. Effect of composition and processing route on the wear behaviour of Al–Si alloys. Scr Mater, 2002, 46(6): 477 doi: 10.1016/S1359-6462(02)00020-9 [3] Li Y, Li J P, Liu L, et al. Evolution mechanism of cast Al–Si alloy surface roughness at high temperature. Chin J Nonferrous Met, 2021, 31(8): 2115 doi: 10.11817/j.ysxb.1004.0609.2021-39721李阳, 李建平, 刘磊, 等. 铸造Al–Si合金表面粗糙度的高温演变机制. 中国有色金属学报, 2021, 31(8): 2115 doi: 10.11817/j.ysxb.1004.0609.2021-39721 [4] Zhao N, Ma H J, Hu Z L, et al. Microstructure and mechanical properties of Al–Mg–Si alloy during solution heat treatment and forging integrated forming process. Mater Charact, 2022, 185: 111762 doi: 10.1016/j.matchar.2022.111762 [5] Flemings M C. Behavior of metal alloys in the semisolid state. Metall Trans B, 1991, 22B: 269 [6] Zhao L P, Zhang Y Z, Li Y Y. Ti element analysis in heat treatment process of A356 aluminum alloys. Powder Metall Technol, 2020, 38(4): 306 doi: 10.19591/j.cnki.cn11-1974/tf.2019050004赵利平, 张彦陟, 李云义. A356铝合金热处理工艺中Ti元素分析. 粉末冶金技术, 2020, 38(4): 306 doi: 10.19591/j.cnki.cn11-1974/tf.2019050004 [7] Zhao Z D, Chen Q, Wang Y B, et al. Microstructural evolution of an ECAE-formed ZK60-RE magnesium alloy in the semi-solid state. Mater Sci Eng A, 2009, 506: 8 doi: 10.1016/j.msea.2008.12.042 [8] Takagi H, Uetani Y, Dohi M, et al. Effects of mechanical stirring and vibration on the microstructure of hypereutectic Al–Si–Cu–Mg alloy billets. Mater Trans, 2007, 48(5): 960 doi: 10.2320/matertrans.48.960 [9] Liu D, Atkinson H V, Jones H. Thermodynamic prediction of thixoformability in alloys based on the Al–Si–Cu and Al–Si–Cu–Mg systems. Acta Mater, 2005, 53(14): 3807 doi: 10.1016/j.actamat.2005.04.028 [10] Shabestari S G, Abdi M, Naghdali S. Effect of thixoforming and precipitation hardening on microstructure and mechanical properties of Al–10.5Si–3Cu–0. 2Mg alloy produced by strain induced melt activation process. J Mater Res Technol, 2021, 15: 4981 [11] Bolouri A, Kang C G. Correlation between solid fraction and tensile properties of semisolid RAP processed aluminum alloys. J Alloys Compd, 2012, 516: 192 doi: 10.1016/j.jallcom.2011.12.045 [12] Alhawari K S, Omar M Z, Ghazali M J, et al. Microstructural evolution during semisolid processing of Al–Si–Cu alloy with different Mg contents. Trans Nonferrous Met Soc China, 2017, 27(7): 1483 doi: 10.1016/S1003-6326(17)60169-9 [13] German R M, Suri P, Park S J. Review: liquid phase sintering. J Mater Sci, 2009, 44: 1 doi: 10.1007/s10853-008-3008-0 [14] Huang P Y. Theory of Power Metallurgy. 2nd Ed. Beijing: Metallurgical Industry Press, 2004黄培云. 粉末冶金原理. 2版. 北京: 冶金工业出版社, 2004 [15] Du Y, Schuster J C, Liu Z K, et al. A thermodynamic description of the Al–Fe–Si system over the whole composition and temperature ranges via a hybrid approach of CALPHAD and key experiments. Intermetallics, 2008, 16(4): 554 doi: 10.1016/j.intermet.2008.01.003 -
下载:
点击查看大图
计量
- 文章访问数: 2219
- HTML全文浏览量: 61
- PDF下载量: 48
- 被引次数: 0
