热处理对真空压铸NZ30K镁合金微观组织及力学性能的影响

doi:10.11901/1005.3093.2018.289

材料研究学报

2019, Vol. 33

Issue (1): 1-8 DOI: 10.11901/1005.3093.2018.289

研究论文

本期目录 | 过刊浏览

热处理对真空压铸NZ30K镁合金微观组织及力学性能的影响

魏杰¹,王渠东^1,²(

),叶兵^1,²,蒋海燕^1,²,丁文江^1,²

1. 上海交通大学材料科学与工程学院轻合金精密成型国家工程研究中心和;金属基复合材料国家重点实验室上海200240
2. 上海材料创新研究院上海 200240

Effect of Heat Treatment on the Microstructure and Mechanical Property of Vacuum Die-casting NZ30K Mg-alloy

Jie WEI¹,Qudong WANG^1,²(

),Bing YE^1,²,Haiyan JIANG^1,²,Wenjiang DING^1,²

1. National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2. Shanghai Innovation Institute for Materials, Shanghai 200240, China

引用本文:

魏杰,王渠东,叶兵,蒋海燕,丁文江. 热处理对真空压铸NZ30K镁合金微观组织及力学性能的影响[J]. 材料研究学报, 2019, 33(1): 1-8.
Jie WEI, Qudong WANG, Bing YE, Haiyan JIANG, Wenjiang DING. Effect of Heat Treatment on the Microstructure and Mechanical Property of Vacuum Die-casting NZ30K Mg-alloy[J]. Chinese Journal of Materials Research, 2019, 33(1): 1-8.

全文: PDF(16233 KB) HTML

摘要:

使用光学显微镜(OM)、扫描电镜(SEM)、能谱分析(EDS)、硬度测试和拉伸性能测试等方法，研究了热处理对真空压铸NZ30K镁合金微观组织及力学性能的影响。结果表明：铸态合金的宏观组织分为表层区和心部区，表层区组织由细小α-Mg等轴晶和分布在晶界的Mg₁₂Nd组成，心部区组织则由细小α-Mg等轴晶、粗大预结晶组织(ESCs)和分布在晶界的离异共晶Mg₁₂Nd组成。在固溶处理过程中心部区晶粒的长大比表层区更为显著，晶界迁移速率与晶粒尺寸不均匀呈正相关性，满足晶粒长大模型v=M₀ exp (-Q/RT) A (1/D₁-1/D₂)。合金的优化热处理工艺为540℃×6 h+200℃×8 h。与铸态合金(UTS=186.0±1.5 MPa，YS=131±2.5 MPa，EL=6.6±0.4%)相比，峰值时效态合金的抗拉强度和屈服强度分别提高到了223.6±4.1 MPa和172.8±2.9 MPa，但延伸率降低到了4.2±0.3%。其强度的提高主要得益于时效析出的片状纳米β"相能够有效地阻碍位错在基面上的滑移。铸态和热处理态合金的表层区断裂模式均为韧性断裂，而心部区的断裂模式在铸态下为准解理断裂、在固溶态下为解理断裂、在峰值时效态下为准解理断裂。

关键词 ：金属材料, NZ30K镁合金, 固溶时效处理, 微观组织, 晶粒生长模型, 力学性能

Abstract：

Effect of heat treatment on the microstructure and mechanical property of vacuum die-casting (VDC) NZ30K Mg-alloy were systematically investigated by means of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), hardness test and tensile test. The results show that the as-cast alloy is composed of a surface zone and a central region. Fine α-Mg matrix and Mg₁₂Nd eutectic compounds were observed in the surface zone and the central region, besides, coarser externally solidified crystals (ESCs) existed in the central region. During solution treatment the grain growth of the central region was more significant than that of the surface zone, which can be explained by the grain growth model of unhomogenized structure, i.e.v=M₀ exp (-Q/RT) A (1/D₁-1/D₂). The optimized heat treatment of the alloy was 540^oC×6 h+200^oC×8 h. Compared with the as-cast alloy, the ultimate tensile strength and yield strength of the peak-aged alloy enhanced from 186.0±1.5 MPa to 223.6±4.1 MPa and from 131±2.5 MPa to 172.8±2.9 MPa respectively, with a decreased elongation (from 6.6±0.4 % to 4.2±0.3%). The strength enhancement may be mainly attributed to the plate-shaped β" precipitates, which could block the dislocation motion effectively. The fractography of surface zone exhibited ductile fracture pattern at different states. However, the fractography of central region showed quasi-cleavage, cleavage and quasi-cleavage fracture patterns for the as-cast, as-solutioned and peak-aged alloys, respectively.

Key words： metallic materials NZ30K alloy solution and aging treatment microstructure grain growth model mechanical property

收稿日期: 2018-04-24

ZTFLH:

TG113

基金资助:国家重点研发计划(2016YFB0301001);高等学校学科创新引智计划(B16032)

作者简介: 魏杰，男，1995年生，博士

	服务

	把本文推荐给朋友
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	魏杰
	王渠东
	叶兵
	蒋海燕
	丁文江
44.8K

链接本文:

https://www.cjmr.org/CN/10.11901/1005.3093.2018.289 或 https://www.cjmr.org/CN/Y2019/V33/I1/1

图1 拉伸试棒和组织观察面的示意图

表1 真空压铸工艺参数

表2 NZ30K镁合金实际成分

图2 铸态合金的宏观组织

图3 铸态合金SEM图像(a)表层区，(b)心部区和(c)点1，(d)点2 EDS结果

图4 铸态合金(a)及其在490℃(b)、510℃(c)、540℃(d)固溶6 h后的金相组织

图5 不同固溶态合金的(a)晶粒尺寸和(b)第二相面积分数的变化

图6 表层区(a)和心部区(b)晶粒的生长模型，其中P为晶界驱动力

图7 不同固溶态(a)510℃×6 h，(b) 540℃×6 h合金的时效硬化曲线

图8 峰值时效态合金(a)表层区和(b)心部区的显微组织

图9 热处理对真空压铸NZ30K合金室温力学性能的影响

图10 铸态(a)、固溶态(b)和峰值时效态(c)合金的拉伸断口形貌

1	FriedrichH., SchumannS.. Research for a “new age of magnesium” in the automotive industry [J]. Journal of Materials Processing Technology, 2001, 117(3): 276
2	FuP H, PengL M, JiangH Y, et al. Tensile properties of high strength cast Mg alloys at room temperature:A review [J]. China Foundry, 2014, 11(4): 227
3	NieJ F, MuddleB. C.. Precipitation in magnesium alloy WE54 during isothermal ageing at 250℃ [J]. Scripta Materialia,1999, 40(10): 1089
4	RzychońT, MichalskaJ, Kie BusA. Effect of heat treatment on corrosion resistance of WE54 alloy [J]. Journal of Achievements in Materials & Manufacturing Engineering, 2007, 20(1-2): 1049
5	LiS Y, LiD J, ZengX Q, et al. Study on Microstructure and Mechanical Properties of Mg-3Nd-0.2Zn-0.4Zr Alloy Processed by Die-Casting [J]. Foundry, 2014(12): 1226
5	李胜勇, 李德江, 曾小勤等. 压铸Mg-3Nd-0.2Zn-0.4Zr合金的组织和力学性能研究 [J]. 铸造， 2014, (12): 1226)
6	FuP H, PengL M, JiangH Y, et al. Effects of heat treatments on the microstructures and mechanical properties of Mg-3Nd-0.2Zn-0.4Zr (wt.%) alloy [J]. Materials Science and Engineering: A, 2008, 486(1-2): 183
7	FuP H, PengL M, JiangH Y, et al. Chemical composition optimization of gravity cast Mg-yNd-xZn-Zr alloy [J]. Materials Science and Engineering: A, 2008, 496(1-2): 177
8	WilsonRobert, BettlesC. J., C. MuddleBarry, et al. Precipitation hardening in Mg-3wt% Nd (-Zn) casting alloys [J]. Trans Tech Publications Ltd., Zurich-Uetikon, Switzerland,2003, 419: 267
9	LuoA A. Magnesium casting technology for structural applications [J]. Journal of Magnesium and Alloys, 2013, 1(1): 2
10	WangX J, ZhuS M, EastonM A, et al. Heat treatment of vacuum high pressure die cast magnesium alloy AZ91 [J]. International Journal of Cast Metals Research, 2014, 27(3): 161
11	HuB, XiongS M, MasayukiM, et al. ShingoIkeda, Relationship Between Porosity Distribution and Mechanical Properties of Vacuum Die Casting AM50 Magnesium Alloy [J]. Foundry,2007, 28(12): 1579
11	胡泊, 熊守美, 村上正幸等. AZ91D镁合金真空压铸力学性能研究 [J]. 铸造技术, 2007, 28(12): 1579)
12	HuB, XiongS M, MasayukiM, et al. ShingoIkeda, Effects of Vacuum Die Casting Processing Parameters on Mechanical Properties of AM50 Magnesium Alloy [J]. Special casting & nonferrous alloys,2009, 29(12): 1120
12	胡泊, 熊守美, 村上正幸等. 真空压铸工艺参数对AM50镁合金力学性能的影响规律 [J]. 特种铸造及有色金属, 2009, 29(12): 1120)
13	WeiJ, HuangG H, YinD D, et al. Effects of ECAP and Annealing Treatment on the Microstructure and Mechanical Properties of Mg-1Y(wt .%) Binary Alloy [J]. Metals, 2017, 7(4): 119
14	LiX B, XiongS M, PengZ. Characterization of the Grain Structures in Vacuum-Assist High- Pressure Die Casting AM60B Alloy [J]. Acta Metallurgica Sinica (English Letters), 2016, 29(7): 619
15	FrederickJ H, MaxHatherly. Recrystallization and related annealing phenomena [M]. (Amsterdam, The Netherlands, Elsevier, 2004) p.219~224
16	HonmaT., OhkuboT., KamadoS., et al. Effect of Zn additions on the age-hardening of Mg-2.0Gd-1.2Y-0.2Zr alloys [J]. Acta Materialia, 2007, 55(12): 4137
17	HeS M, ZengX Q, PengL M, et al. Microstructure and strengthening mechanism of high strength Mg-10Gd-2Y-0.5Zr alloy [J]. Journal of Alloys and Compounds, 2007, 427(1-2): 316
18	SrinivasanA, PillaiU T S, PaiB C. Microstructure and mechanical properties of Si and Sb added AZ91 magnesium alloy [J]. Metallurgical and Materials Transactions A, 2005, 8(36): 2235

[1]	毛建军, 富童, 潘虎成, 滕常青, 张伟, 谢东升, 吴璐. AlNbMoZrB系难熔高熵合金的Kr离子辐照损伤行为[J]. 材料研究学报, 2023, 37(9): 641-648.
[2]	宋莉芳, 闫佳豪, 张佃康, 薛程, 夏慧芸, 牛艳辉. 碱金属掺杂MIL125的CO₂ 吸附性能[J]. 材料研究学报, 2023, 37(9): 649-654.
[3]	赵政翔, 廖露海, 徐芳泓, 张威, 李静媛. 超级奥氏体不锈钢24Cr-22Ni-7Mo-0.4N的热变形行为及其组织演变[J]. 材料研究学报, 2023, 37(9): 655-667.
[4]	邵鸿媚, 崔勇, 徐文迪, 张伟, 申晓毅, 翟玉春. 空心球形AlOOH的无模板水热制备和吸附性能[J]. 材料研究学报, 2023, 37(9): 675-684.
[5]	幸定琴, 涂坚, 罗森, 周志明. C含量对VCoNi中熵合金微观组织和性能的影响[J]. 材料研究学报, 2023, 37(9): 685-696.
[6]	欧阳康昕, 周达, 杨宇帆, 张磊. 含LPSO相Mg-Y-Er-Ni合金的组织和拉伸性能[J]. 材料研究学报, 2023, 37(9): 697-705.
[7]	潘新元, 蒋津, 任云飞, 刘莉, 李景辉, 张明亚. 热挤压钛/钢复合管的微观组织和性能[J]. 材料研究学报, 2023, 37(9): 713-720.
[8]	徐利君, 郑策, 冯小辉, 黄秋燕, 李应举, 杨院生. 定向再结晶对热轧态Cu71Al18Mn11合金的组织和超弹性性能的影响[J]. 材料研究学报, 2023, 37(8): 571-580.
[9]	熊诗琪, 刘恩泽, 谭政, 宁礼奎, 佟健, 郑志, 李海英. 固溶处理对一种低偏析高温合金组织的影响[J]. 材料研究学报, 2023, 37(8): 603-613.
[10]	刘继浩, 迟宏宵, 武会宾, 马党参, 周健, 徐辉霞. 喷射成形M3高速钢热处理过程中组织的演变和硬度偏低问题[J]. 材料研究学报, 2023, 37(8): 625-632.
[11]	陈晶晶, 占慧敏, 吴昊, 朱乔粼, 周丹, 李柯. 纳米晶CoNiCrFeMn高熵合金的拉伸力学性能[J]. 材料研究学报, 2023, 37(8): 614-624.
[12]	由宝栋, 朱明伟, 杨鹏举, 何杰. 合金相分离制备多孔金属材料的研究进展[J]. 材料研究学报, 2023, 37(8): 561-570.
[13]	任富彦, 欧阳二明. g-C₃N₄ 改性Bi₂O₃ 对盐酸四环素的光催化降解[J]. 材料研究学报, 2023, 37(8): 633-640.
[14]	王昊, 崔君军, 赵明久. 镍基高温合金GH3536带箔材的再结晶与晶粒长大行为[J]. 材料研究学报, 2023, 37(7): 535-542.
[15]	刘明珠, 樊娆, 张萧宇, 马泽元, 梁城洋, 曹颖, 耿仕通, 李玲. SnO₂ 作散射层的光阳极膜厚对量子点染料敏化太阳能电池光电性能的影响[J]. 材料研究学报, 2023, 37(7): 554-560.

Viewed

Full text

Abstract

Cited

Shared

Discussed