中国腐蚀与防护学报, 2022, 42(4): 621-628 DOI: 10.11902/1005.4537.2021.149

研究报告

电弧增材制造航空AA2024铝合金的微观结构及其腐蚀行为研究

赵海洋1,2, 高多龙1,2, 张童3, 吕由3, 张宇鹏3, 张欣欣,3, 石鑫1,2, 魏晓静1,2, 刘冬梅1,2, 董泽华3

1.中国石油化工股份有限公司西北油田分公司 乌鲁木齐 830011

2.中国石化缝洞型油藏提高采收率重点实验室 乌鲁木齐 830011

3.华中科技大学化学与化工学院 武汉 430074

Microstructure and Corrosion Evolution of Aerospace AA2024 Al-Alloy Thin Wall Structure Produced Through WAAM

ZHAO Haiyang1,2, GAO Duolong1,2, ZHANG Tong3, LV You3, ZHANG Yupeng3, ZHANG Xinxin,3, SHI Xin1,2, WEI Xiaojing1,2, LIU Dongmei1,2, DONG Zehua3

1.SINOPEC Northwest Company of China Petroleum and Chemical Corporation, Urumqi 830011, China

2.Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-vuggy Reservoirs, SINOPEC, Urumqi 830011, China

3.School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China

通讯作者: 张欣欣,E-mail:xinxinzhang@hust.edu.cn,研究方向为航空结构材料的腐蚀机理、监测手段、表面改性与先进加工方法

收稿日期: 2021-06-29   修回日期: 2021-07-08  

基金资助: 湖北省自然科学基金.  2020CFB295
国家航空科学基金.  2020Z008079004
国家自然科学基金.  52001128

Corresponding authors: ZHANG Xinxin, E-mail:xinxinzhang@hust.edu.cn

Received: 2021-06-29   Revised: 2021-07-08  

Fund supported: Hubei Provincial Natural Science Foundation of China.  2020CFB295
Aeronautical Science Foundation of China.  2020Z008079004
National Natural Science Foundation of China.  52001128

作者简介 About authors

赵海洋,男,1973年生,博士,教授级高级工程师

摘要

研究了电弧增材制造 (WAAM) 航空AA2024铝合金的微观组织结构及其腐蚀行为。通过扫描电镜 (SEM)、透射电镜 (TEM) 和能量色散X射线光谱仪 (EDX),研究了该铝合金腐蚀前后的微观组织结构以阐明其腐蚀行为。结果表明,电弧增材制造AA2024铝合金中,存在熔池区 (MPZ)、熔池边界区 (MPB) 和热影响区 (HAZ)。3个区域中均存在以孤立或成簇的形式存在的S相 (Al2CuMg)、θ相 (Al2Cu) 和α相 (AlFeMnSi) 金属间化合物 (IM)。相对MPZ和HAZ,MPB显示出更高的局部腐蚀敏感性,这与IM的脱合金化行为密切相关。

关键词: 金属间化合物 ; 增材制造 ; 脱合金化 ; AA2024铝合金 ; 局部腐蚀

Abstract

The microstructure and corrosion behaviour of the wire arc additive manufactured (WAAM) thin wall structure of AA2024 Al-alloy are investigated by means of scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectrometer (EDX), as well as immersion test in 3.5%NaCl solution. Three distinctive areas, including melt pool zone (MPZ), melt pool border (MPB) and heat affected zone (HAZ), were formed in the WAAM structure. S-phase, θ-phase and α-phase are present in all three zones, which could exist individually or in cluster. Localized corrosion tends to initiate at MPB rather than HAZ and MPZ, which is closely associated with the de-alloying behaviour of intermetallic (IM) particles.

Keywords: intermetallic ; additive manufacturing ; de-alloying ; AA2024 Al-alloy ; localized corrosion

PDF (18031KB) 元数据 多维度评价 相关文章 导出 EndNote| Ris| Bibtex  收藏本文

本文引用格式

赵海洋, 高多龙, 张童, 吕由, 张宇鹏, 张欣欣, 石鑫, 魏晓静, 刘冬梅, 董泽华. 电弧增材制造航空AA2024铝合金的微观结构及其腐蚀行为研究. 中国腐蚀与防护学报[J], 2022, 42(4): 621-628 DOI:10.11902/1005.4537.2021.149

ZHAO Haiyang, GAO Duolong, ZHANG Tong, LV You, ZHANG Yupeng, ZHANG Xinxin, SHI Xin, WEI Xiaojing, LIU Dongmei, DONG Zehua. Microstructure and Corrosion Evolution of Aerospace AA2024 Al-Alloy Thin Wall Structure Produced Through WAAM. Journal of Chinese Society for Corrosion and Protection[J], 2022, 42(4): 621-628 DOI:10.11902/1005.4537.2021.149

高强铝合金因其高比强度和损伤容限而广泛应用于航空业[1]。近年来,增材制造 (AM),也称作3D打印技术,在金属结构制造领域引起了广泛关注[2-6]。不同于传统的对组件切削-组装的加工模式,AM是一种基于逐层累加的制造方法,可采用最少的原料加工出较为复杂的结构件[7-9]

电弧增材制造 (WAAM) 是以金属丝为原料,通过“自下而上”的电弧焊接实现增材制造的方法[7,10-12]。WAAM具有沉积速率高、设备成本低和结构完整性好等优点,相比于传统制造方法[13],WAAM是一种非常有前景的替代手段,尤其是对具有中低复杂性的部件。

虽然采用AM制备高强铝合金在航空工业领域有着十分光明的前景,但是目前AM高强铝合金并没有实现广泛应用[11,14,15],这主要是因为在制造过程中可能产生包括气泡、热裂纹、残余应力等在内的有害微观结构特征[16,17]。此外,AM过程中复杂的热循环作用容易促使高强铝合金发生冶金转变,从而导致合金化学性质的不均一性,如偏析、金属间化合物和析出相等情况的出现[10,18,19]。由于局部腐蚀倾向于发生在化学性质不均一的缺陷区域[10,20-23],这些复杂而有害的微观结构特征会导致AM合金耐蚀性能降低,从而严重威胁航空飞行器的运行安全。

尽管AM高强铝合金普遍具有较高的腐蚀敏感性,但是现有大多研究工作却忽略了这个问题,而主要关注通过AM工艺参数优化以实现合金优异的力学性能[12,24-26]。本工作在优化参数的基础上,利用WAAM制备了高强AA2024合金薄壁结构,研究其微观结构及局部腐蚀行为。本文的研究成果将为高强度耐蚀铝合金的增材制造提供理论指导。

1 实验方法

采用如图1所示的WAAM设备制造了厚度为~10 mm的AA2024 Al-Cu-Mg合金薄壁结构,其中送丝速度为6 mm/min,焊接速度为0.6 m/min,能量输入为118 J/mm。

图1

图1   WAAM工艺原理图

Fig.1   Schematic diagram of WAAM process


所制备的薄壁结构呈现出明显的层状结构,层高约为1.5 mm。采用碳化硅砂纸将其依次打磨至4000粒度,随后采用3和1 μm的金刚石抛光液对其进行机械抛光处理。机械抛光后,将样品放在丙酮浴中超声清洗,冷风干燥,随后进行扫描电镜 (SEM,Tescan Mira 3) 和能量色散X射线光谱 (EDX,X-Max,Oxford Instrument) 分析。再将机械抛光后的表面在7 ℃的700 mL乙醇和300 mL高氯酸的混合电解液中进行电抛光处理;随后,通过Barker试剂进行阳极氧化;最后,采用光学显微镜进行观察。

在室温下,将抛光后的样品表面暴露于3.5% (质量分数) NaCl溶液中进行浸泡实验。浸泡结束后,使用去离子水将样品冲洗干净,冷风干燥备用。将发生局部腐蚀部位的截面进行机械抛光以便于SEM观察截面腐蚀形貌。采用聚焦离子束技术 (FIB,Tescan Amber) 制备原始材料和浸泡后材料的电子透明薄膜样品,用于透射电镜 (TEM,Tecnai G20) 和EDX分析。

2 实验结果

图2为AA2024合金薄壁结构表面在Barker试剂中阳极氧化后的光学照片。根据晶粒的尺寸和形状,可以观察到3个不同的区域:熔池区 (MPZ)、熔池边界区 (MPB) 和由前沉积层 (PDL) 形成的热影响区 (HAZ)。由图可以看出,MPZ是由形状不规则的大晶粒组成,这些晶粒的尺寸大多为几十微米。与MPZ相邻的是由等轴细晶粒组成的MPB,该区域宽度约200 μm,其晶粒尺寸从几微米到十几微米不等。在MPB之后,PDL中出现HAZ,该区域由尺寸从10到50 μm不等的等轴晶粒组成。此外,在薄壁结构中,还发现了微小孔洞 (图中实线箭头标记),这可能是由于在WAAM过程中残留的保护气体溢出或金属丝熔融过程中氢气的释放导致的。

图2

图2   WAAM薄壁结构经Barker试剂阳极氧化后的显微组织

Fig.2   Grain structure of the WAAM thin wall structure after anodizing in Barker's agent


图3a为WAAM薄壁结构表面的背散射电子图像,可以看出其呈现典型的铸造件微观结构。其中,明亮的微米级粒子为枝晶间金属间化合物 (IM),其在不同区域中呈现显著差异。同时,在薄壁结构组件中,再次发现微小孔洞 (如白色箭头所示)。

图3

图3   WAAM薄壁显微组织结构的SEM形貌

Fig.3   SEM micrographs of the WAAM thin wall structure: (a) general view, (b) MPZ, (c) PMB, (d) HAZ


图3b~d分别为MPZ、MPB和HAZ放大后的SEM像,其晶粒结构与图2一致,并且可以观察到枝晶间IM的详细形态特征。枝晶间IM主要分布在晶界处,尽管在晶粒内也可以发现了一些孤立的IM颗粒 (如虚线箭头所示)。值得注意的是,由于二维SEM成像无法显示枝晶间IM网络沿晶界的三维分布,因此,二维SEM显微照片中晶粒内部出现的孤立IM可能是枝晶间IM的局部片段。

通过EDX对3个典型区域进行元素分析,可以看出WAAM薄壁结构中存在3种不同类型的IM,其典型的EDX谱图如图4a,c,e所示,分别为富Al、Cu和Mg的S相 (Al2CuMg)、富Al和Cu的θ相 (Al2Cu) 和富Al、Fe、Mn和Cu的α相 (AlFeMnCu)。进一步,通过EDX面扫对3个典型区域进行分析,如图4所示。可以明显看出,枝晶间IM以S相 (白色虚线箭头所示) 为主,同时也存在θ相 (红色虚线箭头所示) 和α相 (白色实线箭头所示)。这些枝晶间IM可以孤立存在,也可以成簇存在。对比图4b,d,f可见3个典型区域中IM密度按如下排列:MPB>HAZ>MPZ,这可能是由于MPB相比于MPZ和HAZ的晶粒尺寸更小,晶界面积更大所致。

图4

图4   S相、θ相和α相及薄壁结构中MPZ、MPB和HAZ的SEM像以及相应的EDX图

Fig.4   EDX spectra corresponding to S phase (a), θ phase (c) and α phase (e) and SEM micrographs (corresponding to surface A in Fig.1) along with the corresponding EDX maps from MPZ (b), MPB (d) and HAZ (f) in the thin wall structure


图5a中的高角度环形暗场 (HAADF) 显微照片为典型的IM簇。图中的明暗程度对应不同的原子序数,更亮的区域代表该区域存在的原子序数更高。因此,图5a中亮度波动表明:枝晶间IM簇中存在不同的相。图5b中按Cu、Mg、Fe和Mn的顺序展示了图5a对应的EDX图,表明IM簇由S相 (白色虚线箭头表示)、θ相 (红色虚线箭头表示) 和α相 (白色实线箭头表示) 组成。除了较大的IM外,在图5a中红色实线箭头标记处也观察到大小约几十纳米的析出相,这些析出相也富含Cu和Mg (图5b中用虚线箭头标记),即S析出相。

图5

图5   MPB中金属间化合物团簇的HAADF显微图及其EDX图

Fig.5   HAADF micrograph (a) and its EDX maps (b) of the multi-phase intermetallics in MPB


在微观结构表征后,对WAAM AA2024合金薄壁结构进行腐蚀浸泡实验。由图6a表面A在3.5%NaCl溶液中浸泡30 min后的形貌可以看出,沿着材料累加方向,带状腐蚀特征区会周期性出现,并且相邻带状腐蚀特征区之间的距离约为1.5 mm,这表明局部腐蚀倾向于发生在薄壁结构中每一层的特定区域。当腐蚀浸泡时间延长至10 h (图6b),带状腐蚀特征尺寸显著增加,这表明局部腐蚀的进一步发展。

图6

图6   浸泡30 min和10 h后的WAAM薄壁的光学照片

Fig.6   Photographs of as-manufactured WAAM thin wall structure after 30 min (a) and 10 h (b) immersion


对浸泡30 min后的薄壁结构表面进行SEM观察,腐蚀形貌如图7a所示。在MPB中可以观察到明显的腐蚀产物,而邻近的MPZ和HAZ几乎保持完好,即:在整个薄壁结构中,MPB对于MPZ和HAZ表现出更高的腐蚀敏感性。

图7

图7   浸泡30 min和10 h后WAAM薄壁结构的SEM形貌

Fig.7   SEM micrographs of the WAAM thin wall structure after 30 min immersion: surface morphology (a), local magnification of the MPB region (b), cross-section morphology (c) and after 10 h immersion: surface morphology (d), surface morphology with corrosion products removed (e)


MPB区域内典型的局部腐蚀形貌如图7b所示。显然,在MPB内,枝晶间IM更容易被腐蚀 (虚线箭头)。此外,还观察一些由腐蚀产物脱水造成的细裂纹 (实线箭头)。

图7b对应的截面图如图7c所示,由于在对截面进行机械抛光过程中,可能引起腐蚀产物脱落,因此在图7c中没有观察到腐蚀产物的存在。对图7c的仔细观察可发现枝晶间IM优先被侵蚀 (白色箭头标记),初步表明MPB中局部腐蚀的萌生与枝晶间IM密切相关。

浸泡10 h后,薄壁结构表面出现了大量腐蚀产物的沉积 (图7d)。为更好地观测不同区域的局部腐蚀形貌,采用0.25 μm的金刚石抛光膏对表面进行轻微抛光以去除腐蚀产物。处理后的典型表面形貌如图7c所示,薄壁表面呈现出非均匀腐蚀特点,其中MPB腐蚀最为严重,出现大面积点蚀坑甚至晶粒脱落;HAZ的腐蚀情况次之,出现了明显的点蚀坑;而MPZ仅可见少量点蚀坑,说明该区域的腐蚀并不明显。结合腐蚀浸泡30 min后的腐蚀特点 (图7),局部腐蚀由MPB萌生后,倾向于向HAZ而非MPZ发展,说明HAZ相对于MPZ表现出更高的腐蚀敏感性。此外,仔细观察腐蚀形貌发现,局部腐蚀更倾向于沿着枝晶间IM发展,与图7结果一致。

图8a为局部腐蚀部位横截面的HAADF显微图,可以看出局部腐蚀只发生在枝晶间IM的周围区域,导致沿着枝晶边界的网状区域均被侵蚀。

图8

图8   MPB中典型局部腐蚀部位截面HAADF像及典型纳米粒子的EDX、高分辨TEM像和电子衍射像

Fig.8   HAADF micrograph of the cross section at a typical localized corrosion site in MPB (a), framed area in Fig.8a at increased magnification (b), EDX spectrum (c), high resolution TEM micrograph (d) and electron diffraction of a typical nanoparticle in Fig.8b (e)


图8b展示了图8a中所选区域,可以看到被侵蚀的IM具有典型的类海绵特征,而这种类海绵特征的IM可能为脱合金化的S相或θ[27-30]。在其周围还存在着尺寸为几百纳米的点蚀坑,并且这些点蚀坑不断向基体中扩张。仔细观察图8b中的点蚀坑边缘可以发现阶梯状的点蚀壁。这些点蚀壁的取向与其相邻近的析出相基本保持一致,表明这些析出相与点蚀的晶体学特征密切相关。值得注意的是,图8b中红点区域对应的EDX结果如图8c所示,相比于图5,Cu与Al的比例达到3.68,远高于未被腐蚀的IM (图4),进一步说明了IM脱合金化现象的发生。此外,还可见一些相对于周围基体更明亮的纳米颗粒 (虚线箭头所示),即:富Cu纳米颗粒[19,28,30]。这些纳米颗粒并非仅存在于IM中,其周围区域也观察到其分布。由于富Cu纳米颗粒可作为有效阴极,这将加速IM及其周边区域的腐蚀过程[31]图8c、d富Cu纳米颗粒典型高分辨TEM像和对应的电子衍射像表明,其晶体结构与金属Cu一致 (PDF#04-0836),表明该纳米颗粒属于金属Cu。

3 分析讨论

在WAAM过程中,电弧持续提供能量将金属丝材熔化形成熔池,然后熔池再与先前的沉积层 (PDL) 冶金结合,形成具有层状结构的WAAM合金。由于熔池与PDL结合过程中对PDL有一个加热作用,因此会导致其轻微的晶粒粗化,从而形成HAZ。同时,在熔池凝固过程中,部分熔融的金属丝材可作为有效的晶核,促进晶粒的形成,从而在合金中形成枝晶。由于高密度晶核的促进作用,形成以细小等轴晶为主的MPB。随后,由于晶核的消耗及熔池温度的梯度改变,枝晶不断生长,形成较大尺寸的晶粒,从而在WAAM AA2024合金中形成MPZ (图2和3)。

在凝固过程中,Cu和Mg可能在枝晶间发生偏析,从而形成含Cu和/或Mg的枝晶间IM,即S相和θ相 (图3)。在凝固的最后阶段,较高浓度的Cu和Mg会在共晶反应前促使导致S析出相在IM周边沉淀 (图4)。同样,Mn和Fe也会在枝晶间发生偏析,进而形成α相Al-Fe-Mn-Cu,这些α相可能与S相和θ相一起形成IM簇 (图4)。

复杂的微观组织结构导致AA2024薄壁结构具有很高的局部腐蚀敏感性。通常,局部腐蚀优先发生在与基体易形成电偶对的IM (S相、θ相和α相) 周围。相对于θ相和α相,S相中含有更高比例的活性元素 (Al、Mg),因此S相最易引起局部腐蚀[33]

3个特征区域中S相含量呈现如下趋势:MPB>HAZ>MPZ (图3),导致局部腐蚀倾向于在S相含量最高的MPB中萌生 (图4)。随着腐蚀时间的延长,局部腐蚀向S相含量次之的HAZ发展,而S相含量最低的MPZ的腐蚀则并不明显 (图7d,e)。因此,腐蚀后的薄壁结构表现出非均匀腐蚀的特点 (图5)。

相对于铝合金基体而言,富含Mg和Al的S相将作为阳极优先被腐蚀,导致S相中Mg和Al的选择性溶解[27,33]。S相的脱合金化过程产生的较高阳极电流需要等值的阴极电流匹配,从而促进合金基体周围的氧还原反应。在S相/Al界面处的大量缺陷也会促进这一过程,并进一步加速S相的脱合金化[29,30]

S相的脱合金化形成了富Cu的残余物,并导致Cu纳米颗粒分布在其周围区域 (图8)[34]。S相残余物的高Cu含量导致其相对铝基体的电化学性质发生转变,即:S相从富Mg和Al的阳极转变为富Cu的阴极,并将进一步促进氧的还原反应,从而在S相残余物的周围区域形成明显的碱性环境[35]

起到保护作用的氧化铝钝化膜在碱性环境中迅速劣化,导致铝基体出现局部阳极溶解[35-37]。同时,随着MPB中S相的不断脱合金化,富Cu的S相残余物与其周围的富铜纳米颗粒提供了足够高的阴极电流,加速了该区域合金基体的阳极溶解过程。因此,S相周围的合金基体的阳极溶解会显著加快,导致MPB中出现大量点蚀,并将持续促进局部腐蚀的进一步发展。

4 结论

(1) 在WAAM AA2024薄壁结构中出现3个特征区域:熔池区 (MPZ)、熔池边界区 (MPB) 和热影响区 (HAZ)。

(2) 所有特征区域中,均存在枝晶间金属间化合物,包括富含Al、Cu和Mg的S相,富含Al、Cu的θ相和富含Al、Cu、Fe和Mn的α相,这些金属间化合物既可以孤立存在,也可以以团簇形式存在。

(3) 除了枝晶间金属间化合物外,还观察到细小的S析出相,这些S析出相倾向于分布在枝晶间金属间化合物的周围区域。

(4) S相的脱合金化和随后引起的Cu的再分布可促进附近区域铝基体的阳极溶解,从而导致MPB中局部腐蚀的萌生,并促进其进一步向HAZ发展。

参考文献

Ding Q M, Qin Y X, Cui Y Y.

Galvanic corrosion of aircraft components in atmospheric environment

[J]. J. Chin. Soc. Corros. Prot., 2020, 40: 455

[本文引用: 1]

丁清苗, 秦永祥, 崔艳雨.

大气环境中飞机构件的电偶腐蚀研究

[J]. 中国腐蚀与防护学报, 2020, 40: 455

[本文引用: 1]

Rioja R J, Liu J.

The evolution of Al-Li base products for aerospace and space applications

[J]. Metall. Mater. Trans., 2012, 43A: 3325

[本文引用: 1]

Gong S L, Suo H B, Li H X.

Development and application of metal Additive manufacturing technology

[J]. Aeronaut. Manuf. Technol., 2013, (13): 66

巩水利, 锁红波, 李怀学.

金属增材制造技术在航空领域的发展与应用

[J]. 航空制造技术, 2013, (13): 66

Yang Q, Lu Z L, Huang F X, et al.

Research on status and development trend of laser additive manufacturing

[J]. Aeronaut. Manuf. Technol., 2016, (12): 26

杨强, 鲁中良, 黄福享 .

激光增材制造技术的研究现状及发展趋势

[J]. 航空制造技术, 2016, (12): 26

Karabin L M, Bray G H, Rioja R J, et al.

Al-Li-Cu-Mg-(Ag) products for lower wing skin applications

[A]. Proceedings of the 13th International Conference on Aluminum Alloys [C]. Cham, 2012: 529

Lin X, Huang W D.

High performance metal additive manufacturing technology applied in aviation field

[J]. Mater. China, 2015, 34: 684

[本文引用: 1]

林鑫, 黄卫东.

应用于航空领域的金属高性能增材制造技术

[J]. 中国材料进展, 2015, 34: 684

[本文引用: 1]

Williams S W, Martina F, Addison A C, et al.

Wire+arc additive manufacturing

[J]. Mater. Sci. Technol., 2016, 32: 641

DOI      URL     [本文引用: 2]

Frazier W E.

Metal additive manufacturing: a review

[J]. J. Mater. Eng. Perform., 2014, 23: 1917

DOI      URL    

Gong X B, Anderson T, Chou K, et al.

Review on powder-based electron beam additive manufacturing technology

[A]. ASME/ISCIE 2012 International Symposium on Flexible Automation [C]. St. Louis, 2012: 507

[本文引用: 1]

Zhang X X, Lv Y, Tan S H, et al.

Microstructure and corrosion be/haviour of wire arc additive manufactured AA2024 alloy thin wall structure

[J]. Corros. Sci., 2021, 186: 109453

DOI      URL     [本文引用: 3]

Vimal K E K, Srinivas M N, Rajak S.

Wire arc additive manufacturing of aluminium alloys: a review

[J]. Mater. Today: Proc., 2021, 41: 1139

[本文引用: 1]

Wang F D, Williams S, Colegrove P, et al.

Microstructure and mechanical properties of wire and arc additive manufactured Ti-6Al-4V

[J]. Metall. Mater. Trans., 2013, 44A: 968

[本文引用: 2]

Qiao J S, Xia Z H, Liu L B, et al.

Corrosion resistance of aluminum-magnesium bimetal composite material prepared by isothermal indirect extrusion

[J]. J. Chin. Soc. Corros. Prot., 2021, 41: 255

[本文引用: 1]

乔及森, 夏宗辉, 刘立博 .

铝镁双金属反向等温包覆挤压棒材耐腐蚀性能

[J]. 中国腐蚀与防护学报, 2021, 41: 255

[本文引用: 1]

Bartkowiak K, Ullrich S, Frick T, et al.

New developments of laser processing aluminium alloys via additive manufacturing technique

[J]. Phys. Proced., 2011, 12: 393

DOI      URL     [本文引用: 1]

Yang X Y, Li Y, Zhao P K, et al.

Research status and challenges of wire and arc additive manufacturing in material preparation

[J]. Weld. Join., 2018, (8): 14

[本文引用: 1]

杨笑宇, 李言, 赵鹏康 .

电弧增材制造技术在材料制备中的研究现状及挑战

[J]. 焊接, 2018, (8): 14

[本文引用: 1]

Moran T P, Warner D H, Phan N.

Scan-by-scan part-scale thermal modelling for defect prediction in metal additive manufacturing

[J]. Addit. Manuf., 2021, 37: 101667

[本文引用: 1]

Plessis A D, Yadroitsava I, Yadroitsev I.

Effects of defects on mechanical properties in metal additive manufacturing: a review focusing on X-ray tomography insights

[J]. Mater. Design, 2019, 187: 108385

[本文引用: 1]

Geng R W, Du J, Wei Z Y, et al.

Multiscale modelling of microstructure, micro-segregation, and local mechanical properties of Al-Cu alloys in wire and arc additive manufacturing

[J]. Addit. Manuf., 2020, 36: 1017

[本文引用: 1]

Zhang X X, Liu B, Zhou X R, et al.

Laser welding introduced segregation and its influence on the corrosion behaviour of Al-Cu-Li alloy

[J]. Corros. Sci., 2018, 135: 177

DOI      URL     [本文引用: 2]

Rafieazad M, Mohammadi M, Nasiri A M.

On microstructure and early stage corrosion performance of heat treated direct metal laser sintered AlSi10Mg

[J]. Addit. Manuf., 2019, 28: 107

DOI      [本文引用: 1]

This study examines the impact of low-temperature heat-treatment on the microstructure and corrosion performance of direct metal laser sintered (DMLS)-AlSi10Mg alloy. Differential scanning calorimetry (DSC) was used to determine the phase(s) transition temperatures in the alloy. Two exothermic phenomena were detected and associated with the Mg2Si precipitation and Si phase precipitation in the as-printed alloy. Based on DSC results, thermal-treatments including below and above the active Si precipitation temperature at 200 degrees C and 300 degrees C, respectively, and 350 degrees C as an upper limit temperature for 3 h were applied to the as-printed samples. Scanning electron microscopy and X-ray diffraction analysis confirmed that heat-treatment from 200 degrees C to 350 degrees C promotes the homogeneity of the microstructure, characterized by uniform distribution of eutectic Si in alpha-Al matrix. To investigate the impact of the applied heat-treatment cycles on corrosion resistance of DMLS-AlSi10Mg at early stage of immersion, anodic polarization testing and electrochemical impedance spectroscopy were performed in aerated 3.5 wt.% NaCl solution. The results revealed more uniformly distributed pitting attack on the corroded surfaces by increasing the heat-treatment temperature up to 300 degrees C, attributed to the more protective nature of the spontaneously air-formed passive layer on the surface of the alloy at initial immersion time. Further increase of the heat treatment temperature to 350 degrees C induced severe localized corrosion attacks near the coarse Si particles, ascribed to the increased potential difference between the coalesced Si particles and aluminum matrix galvanic couple. In comparison, the corrosion of the as-printed and 200 degrees C heat treated samples was characterized by a penetrating selective attack along the melt pool boundaries, leading to a higher corrosion current density and an active surface at early exposure, associated with the weakness of the existing passive film on their surfaces.

Rubben T, Revilla R I, De Graeve I.

Influence of heat treatments on the corrosion mechanism of additive manufactured AlSi10Mg

[J]. Corros. Sci., 2019, 147: 406

DOI     

This study focuses on the effect of heat treatments on the microstructure and corrosion behaviour of additive manufactured AlSi10Mg specimens. Non heat treated, artificially aged and stress released specimens were studied. The microstructure showed an evolution from cellular aluminium cells surrounded by a 3D network of fibrous eutectic silicon phase to coarse separated silicon particles. The corrosion behaviour was found to change with the heat treatments. Untreated and artificially aged specimens showed superficial corrosion attacks with microcrack formation while stress released specimens showed penetrating attacks without microcrack formation. Mechanisms were proposed for the microstructure evolution and the different corrosion behaviours.

Gharbi O, Jiang D, Feenstra D R, et al.

On the corrosion of additively manufactured aluminium alloy AA2024 prepared by selective laser melting

[J]. Corros. Sci., 2018, 143: 93

DOI      URL    

Fathi P, Mohammadi M, Duan X L, et al.

A comparative study on corrosion and microstructure of direct metal laser sintered AlSi10Mg_200C and die cast A360.1 aluminum

[J]. J. Mater. Process. Tech., 2018, 259: 1

DOI      URL     [本文引用: 1]

Wang P, Zhang Z D, Song G, et al.

Analysis of laser-arc composite additive manufacturing process for aluminum alloy

[J]. Weld. Technol., 2016, 45(10): 10

[本文引用: 1]

王鹏, 张兆栋, 宋刚 .

铝合金激光-电弧复合增材制造工艺分析

[J]. 焊接技术, 2016, 45(10): 10

[本文引用: 1]

Fang X W, Zhang L J, Chen G P, et al.

Microstructure evolution of wire-arc additively manufactured 2319 aluminum alloy with interlayer hammering

[J]. Mater. Sci. Eng., 2021, 800A: 140168

Yoder J K, Griffiths R J, Yu H Z.

Deformation-based additive manufacturing of 7075 aluminum with wrought-like mechanical properties

[J]. Mater. Design, 2021, 198: 109288

[本文引用: 1]

Hashimoto T, Zhang X, Zhou X, et al.

Investigation of dealloying of S phase (Al2CuMg) in AA 2024-T3 aluminium alloy using high resolution 2D and 3D electron imaging

[J]. Corros. Sci., 2016, 103: 157

DOI      URL     [本文引用: 2]

Zhang X, Hashimoto T, Lindsay J, et al.

Investigation of the de-alloying behaviour of θ-phase (Al2Cu) in AA2024-T351 aluminium alloy

[J]. Corros. Sci., 2016, 108: 85

DOI      URL     [本文引用: 1]

Erlebacher J, Aziz M J, Karma A, et al.

Evolution of nanoporosity in dealloying

[J]. Nature, 2001, 410: 450

DOI      URL     [本文引用: 1]

Buchheit R G, Grant R P, Hlava P F, et al.

Local dissolution phenomena associated with S phase (Al2CuMg) particles in aluminum alloy 2024-T3

[J]. J. Electrochem. Soc., 1997, 144: 2621

DOI      URL     [本文引用: 3]

Boag A, Taylor R J, Muster T H, et al.

Stable pit formation on AA2024-T3 in a NaCl environment

[J]. Corros. Sci., 2010, 52: 90

DOI      URL     [本文引用: 1]

Boag A, Hughes A E, Glenn A M, et al.

Corrosion of AA2024-T3 part I: localised corrosion of isolated IM particles

[J]. Corros. Sci., 2011, 53: 17

DOI      URL    

Hashimoto T, Curioni M, Zhou X, et al.

Investigation of dealloying by ultra-high-resolution nanotomography

[J]. Surf. Interface Anal., 2013, 45: 1548

DOI      URL     [本文引用: 2]

Zhou X, Luo C, Hashimoto T, et al.

Study of localized corrosion in AA2024 aluminium alloy using electron tomography

[J]. Corros. Sci., 2012, 58: 299

DOI      URL     [本文引用: 1]

Zhang X X, Zhou X R, Hashimoto T, et al.

Localized corrosion in AA2024-T351 aluminium alloy: transition from intergranular corrosion to crystallographic pitting

[J]. Mater. Charact., 2017, 130: 230

DOI      URL     [本文引用: 2]

Szklarska-Smialowska Z.

Pitting corrosion of aluminum

[J]. Corros. Sci., 1999, 41: 1743

DOI      URL    

Zhang X X, Jiao Y B, Yu Y, et al.

Intergranular corrosion in AA2024-T3 aluminium alloy: the influence of stored energy and prediction

[J]. Corros. Sci., 2019, 155: 1

DOI      URL     [本文引用: 1]

/