采用高压扭转(HPT)工艺对Mg-8Gd-3Y-0.4Zr(GW83K)合金进行剧烈塑性变形加工,通过显微组织观察、物相分析、显微硬度测定、开路电位测试、动极化曲线测试、交流阻抗谱及扫描开尔文探针分析,对比研究了HPT前后GW83K合金的显微组织和耐蚀性.结果表明:经5圈高压扭转后,GW83K合金的晶粒细化不显著,物相结构亦无变化,晶粒中出现大量孪晶和位错,试样中心区域和边缘区域的晶粒尺寸无明显差异,但边缘区域硬度远高于中心区域.HPT后镁合金在空气中伏打电位较低,在3.5％(质量分数)NaCl溶液中浸泡时开路电位迅速稳定(约1 h)但稳定值较负,腐蚀电流密度较大,电化学阻抗较小且随浸泡时间延长而减少,其耐蚀性不及未HPT加工的初始态合金.在0.1 mol/L NaOH溶液中,浸泡初期初始态和HPT态合金开路电位较接近,交流阻抗相差不大,浸泡6h后初始态的电化学阻抗容抗弧直径则明显大于HPT态样品.极化曲线显示HPT态合金在碱性溶液中的维钝区间减小,维钝电流密度增大,初次击穿电压负移.HPT加工虽有助于镁合金表面快速形成钝化膜(不能有效保护基体),却使镁基体更活泼(溶解加速),GW83K镁合金耐蚀性下降.
参考文献
| [1] | 黄亮;黄元伟;王晨;卫中领.含稀土元素的Mg-Al合金在NaCl溶液中腐蚀产物膜的研究[J].中国腐蚀与防护学报,2002(3):167-171. |
| [2] | J.H. Gao;S.K. Guan;Z.W. Ren;Y.F. Sun;S.J. Zhu;B. Wang.Homogeneous corrosion of high pressure torsion treated Mg-Zn-Ca alloy in simulated body fluid[J].Materials Letters,20114(4):691-693. |
| [3] | Mengyan Nie;Chuan Ting Wang;Minghong Qu;Nong Gao;Julian A. Wharton;Terence G. Langdon.The corrosion behaviour of commercial purity titanium processed by high-pressure torsion[J].Journal of Materials Science,20147(7):2824-2831. |
| [4] | 汪彬;杨院生;周吉学;童文辉.脉冲磁场对Mg-Gd-Y-Zr合金凝固及力学性能的影响[J].稀有金属材料与工程,2009(3):519-522. |
| [5] | C. op't Hoog;N. Birbilis;Y. Estrin.Corrosion of Pure Mg as a Function of Grain Size and Processing Route[J].Advanced Engineering Materials,20086(6):579-582. |
| [6] | Christopher M. A. Brett;Lidia Dias;Bruno Trindade;Robert Fischer;Sascha Mies.Characterisation by EIS of ternary Mg alloys synthesized by mechanical alloying[J].Electrochimica Acta,20068/9(8/9):1752-1760. |
| [7] | Hiroyuki Miyamoto;Kohei Harada;Takuro Mimaki;Alexei Vinogradov;Satoshi Hashimoto.Corrosion of ultra-fine grained copper fabricated by equal-channel angular pressing[J].Corrosion Science: The Journal on Environmental Degradation of Materials and its Control,20085(5):1215-1220. |
| [8] | N. Birbilis;K. D. Ralston;S. Virtanen;H. L. Fraser;C. H. J. Davies.Grain character influences on corrosion of ECAPed pure magnesium[J].Corrosion Engineering, Science and Technology,20103(3):224-230. |
| [9] | Yuntian T. Zhu;Terry C. Lowe;Terence G. Langdon.Performance and applications of nanostructured materials produced by severe plastic deformation[J].Scripta materialia,20048(8):825-830. |
| [10] | Martin Joensson;Dan Persson;Christofer Leygraf.Atmospheric corrosion of field-exposed magnesium alloy AZ91D[J].Corrosion Science: The Journal on Environmental Degradation of Materials and its Control,20085(5):1406-1413. |
| [11] | Xing-Wu Guo;Jian-Wei Chang;Shang-Ming He;Wen-Jiang Ding;Xishu Wang.Investigation of corrosion behaviors of Mg-6Gd-3Y-0.4Zr alloy in NaCl aqueous solutions[J].Electrochimica Acta,20077(7):2570-2579. |
| [12] | Jianwei Chang;Xingwu Guo;Shangming He;Penghuai Fu;Liming Peng;Wenjiang Ding.Investigation of the corrosion for Mg-xGd-3Y-0.4Zr (x = 6,8,10,12 wt%) alloys in a peak-aged condition[J].Corrosion Science: The Journal on Environmental Degradation of Materials and its Control,20081(1):166-177. |
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%