随着国家对具有放射性危害的钍资源有计划性的管理,钍的价格不断上升,推动了焊接领域环保钨电极替代钍的发展.对市场上现有替代钍钨的Ce-W,三元稀土W电极(La-Ce-Y)以及美国市场上积极推广的E3电极的焊接性能进行研究,采用钨极氩弧焊(TIG)直流正接(DCSP)的方法研究了几种电极的高温抗烧损性能,尺寸稳定性以及静特性曲线,并对燃弧后电极尖端的表面形貌进行了扫描电镜(SEM)观察,对稀土添加相La2O3,Y2O3,CeO2在电极尖端轴向分布进行了能谱分析(EDX).对比试验结果发现,在焊接电流200 A工作5h后,E3和WX电极的烧损量明显小于Th-W,Ce-W电极,且质量损失随时间呈近似的线性关系,尺寸稳定性好.从金相组织可以看出Th-W,Ce-W电极再结晶晶粒粗大,E3和WX电极的再结晶晶粒小,再结晶程度较弱,从侧面说明E3和WX电极工作温度较低,电子发射能力强.几种稀土氧化物的行为揭示了电极性能差异的本质原因,多元电极中,CeO2的扩散速率最快,使得其在小电流焊接和起弧过程中作用明显.Y2O3和La2O3热稳定性好,只有在较高温度时其扩散速率才明显增加,因此它们在大电流长时间焊接时作用突出.由于几种元素的协同作用,降低了电极表面的逸出功,并使得电子发射过程稳定.因此,三元稀土钨电极(WX)具有优异的焊接性能.
参考文献
| [1] | 王发展,张晖,丁秉钧.W-ThO2电极材料的研究进展[J].兵器材料科学与工程,2001(04):61-64. |
| [2] | Wang FZ.;Zhang H.;Ding BJ.;Zhu RH. .A thermionic tungsten cathode activated with nanothoria and prepared by swaging method[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2002(1/2):59-63. |
| [3] | 杨萌萌,屠海令,张心强,熊玉华,王小娜,杜军.CeO2掺杂对HfO2栅介质电学特性的影响[J].稀有金属,2012(02):292-296. |
| [4] | 崔超鹏,张国赏,魏世忠,徐流杰.Zr元素对TZM合金组织和性能的影响[J].稀有金属,2012(05):711-715. |
| [5] | Chen Z.;Zhou M. .MORPHOLOGICAL EVOLUTION OF SECOND-PHASE PARTICLES DURING THERMOMECHANICAL PROCESSING OF W-La_2O_3 ALLOY[J].Scripta materialia,2000(4):291-297. |
| [6] | Casado E.;Colomer V.;Munoz-Serrano E.;Sicilia R. .An experimental comparison of the erosion in tungsten cathodes doped with different rare-earth elements[J].Journal of Physics, D. Applied Physics: A Europhysics Journal,2002(10):992-997. |
| [7] | Sillero, JA;Ortega, D;Munoz-Serrano, E;Casado, E .An experimental study of thoriated tungsten cathodes operating at different current intensities in an atmospheric-pressure plasma torch[J].Journal of Physics, D. Applied Physics: A Europhysics Journal,2010(18):185204:1-185204:8. |
| [8] | Xiaoli Xi;Zuoren Nie;Jiancan Yang .Preparation and characterization of nanopowder for emission materials by freeze-drying[J].International Journal of Refractory Metals & Hard Materials,2006(3):210-214. |
| [9] | 柳振平,黎向锋,左敦稳,王宏宇,孙玉利,江世好.微米CeO2的细化及其悬浮液的分散稳定性研究[J].稀有金属,2012(05):767-773. |
| [10] | Aguirre, M.V.;Martín, A.;Pastor, J.Y.;Llorca, J.;Monge, M.A.;Pareja, R. .Mechanical properties of tungsten alloys with Y_2O_3 and titanium additions[J].Journal of Nuclear Materials: Materials Aspects of Fission and Fusion,2011(1/3):516-519. |
| [11] | Y. Chen;Y. C. Wu;F. W. Yu .Microstructure and mechanical properties of tungsten composites co-strengthened by dispersed TiC and La_2O_3 particles[J].International Journal of Refractory Metals & Hard Materials,2008(6):525-529. |
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%