Experimental study on the transformation of the W70Cu30 anode erosion mode in DC gaseous arcs—better insights into mechanisms of electrode erosion behavior using in situ diagnosis

This research concentrates on the erosion mechanism of the W70Cu30 anode in DC gaseous arcs. An in situ diagnostic system including the measurement of the anode surface temperature and the fast-imaging of the erosion process was developed. The influence of gas media He, N2, H2, Ar and current, varying from 50 A to 400 A, was investigated. Two erosion modes were observed, namely an evaporation-dominated mode and a splash-dominated mode. The results indicate that the detachment of the splashing droplet is driven by the explosion of surface bubbles, and it is the surface temperature of the anode that determines the size of the surface bubble as well as the splashing erosion rate. Moreover, the prior vaporization of Cu dispersed in the W70Cu30 anode limits the fusion of the W skeleton but promotes the generation of molten ejections by the explosions of Cu vapor bubbles when the topmost Cu is absent. The large difference between W and Cu in melting and boiling temperatures controls the formation of the molten pool on the W70Cu30 anode and leads to the transition of the two erosion modes. The experimental results contribute to a fundamental understanding of the interaction between thermal plasmas and materials.

[1]  A. Murphy,et al.  Foundations of High-Pressure Thermal Plasmas , 2018, Plasma Sources Science and Technology.

[2]  Haibo Yu,et al.  Corrosion, oxidation, erosion and performance of Ag/W-based circuit breaker contacts: A review , 2018 .

[3]  Shuhao Wang,et al.  Influence of a Scanning Radial Magnetic Field on Macroparticle Reduction of Arc Ion-Plated Films , 2018 .

[4]  Yingsan Geng,et al.  Optical absorption spectroscopy of metallic (Cr) vapor in a vacuum arc , 2018 .

[5]  Haonan Sun,et al.  Visualization and mechanisms of splashing erosion of electrodes in a DC air arc , 2017 .

[6]  Takayuki Watanabe,et al.  Diode-rectified multiphase AC arc for the improvement of electrode erosion characteristics , 2017 .

[7]  S. Jia,et al.  Modeling of cathode spot crater formation and development in vacuum arc , 2017 .

[8]  R. Methling,et al.  Anode Surface Temperature Determination in High-Current Vacuum Arcs by Different Methods , 2017, IEEE Transactions on Plasma Science.

[9]  J. Chapuis,et al.  Liquid metals surface temperature fields measurements with a two-colour pyrometer , 2017 .

[10]  J. Rosen,et al.  Macroparticle generation in DC arc discharge from a WC cathode , 2017 .

[11]  Siba Sankar Mahapatra,et al.  A particle swarm approach for multi-objective optimization of electrical discharge machining process , 2016, J. Intell. Manuf..

[12]  Takayuki Watanabe,et al.  Investigation of erosion mechanism of tungsten-based electrode in multiphase AC arc by high-speed visualization of electrode phenomena , 2016 .

[13]  Takayuki Watanabe,et al.  Investigation of the relationship between arc-anode attachment mode and anode temperature for nickel nanoparticle production by a DC arc discharge , 2016 .

[14]  Rama Govindarajan,et al.  Dynamics of an initially spherical bubble rising in quiescent liquid , 2015, Nature Communications.

[15]  J. Šonský,et al.  Diagnostics of cathode material loss in cutting plasma torch , 2014 .

[16]  V. Nemchinsky.  Erosion of Thermionic Cathodes in Welding and Plasma Arc Cutting Systems , 2014, IEEE Transactions on Plasma Science.

[17]  Y. Hirata,et al.  3D temperature measurement of tandem TIG arc plasma , 2013, Welding in the World.

[18]  E. Siewert,et al.  Determination of enthalpy, temperature, surface tension and geometry of the material transfer in PGMAW for the system argon–iron , 2013 .

[19]  J. Caltagirone,et al.  Analysis by modeling of plasma flow interactions with liquid injection , 2013 .

[20]  T. Iwao,et al.  Anode jet generation conditions affected by the radial current density distribution for maintaining current continuity , 2013 .

[21]  J. Trelles.  Formation of self-organized anode patterns in arc discharge simulations , 2012, 1301.0742.

[22]  Xiaoping Song,et al.  Liquid phase separation of Cu–Cr alloys during the vacuum breakdown , 2011 .

[23]  Wernher Brevis,et al.  Integrating cross-correlation and relaxation algorithms for particle tracking velocimetry , 2011 .

[24]  Frederic Pons,et al.  Electrical contact material arc erosion: experiments and modeling towards the design of an AgCdO substitute , 2010 .

[25]  P. A. Mlsna,et al.  Gradient and Laplacian Edge Detection , 2009 .

[26]  J. Lowke,et al.  Influence of shielding gas composition on arc properties in TIG welding , 2008 .

[27]  J. Heberlein,et al.  Anode attachment modes and their formation in a high intensity argon arc , 2007 .

[28]  A. Essiptchouk,et al.  The effect of surface electrode temperature on cold electrode erosion behaviour , 2007 .

[29]  Manabu Tanaka,et al.  Predictions of weld pool profiles using plasma physics , 2007 .

[30]  Q. Jiang,et al.  Surface tension and its temperature coefficient for liquid metals. , 2005, The journal of physical chemistry. B.

[31]  G. Pottlacher,et al.  Spectral Emissivities and Emissivity X-Points of Pure Molybdenum and Tungsten , 2005 .

[32]  J. Heberlein,et al.  Erosion mechanisms of hafnium cathodes at high current , 2005 .

[33]  V. Nemchinsky.  Cyclic erosion of a cathode in high-pressure arcs , 2003 .

[34]  R.-T. Lee,et al.  Erosion mechanism of silver in a single arc discharge across a static gap , 2002 .

[35]  Anthony B. Murphy,et al.  Thermal plasmas in gas mixtures , 2001 .

[36]  M. Casanove,et al.  Synthesis and Magnetic Properties of Nickel Nanorods , 2001 .

[37]  B. Juttner,et al.  Topical Review: Cathode Spots of Electric Arcs , 2001 .

[38]  Burkhard Jüttner.  Cathode spots of electric arcs , 2001 .

[39]  J. Heberlein,et al.  An experimental investigation of factors affecting arc-cathode erosion , 1998 .

[40]  K. Nagata,et al.  Discontinuity in normal spectral emissivity of solid and liquid copper at the melting point , 1997 .

[41]  V. Dembovský.  Thermodynamics of dissolution and liberation of gases in the atomization of molten metals by plasma-induced expansion , 1997 .

[42]  K. Sawa,et al.  Effect of arc behavior on material transfer: a review , 1996, Electrical Contacts - 1996. Proceedings of the Forty-Second IEEE Holm Conference on Electrical Contacts. Joint with the 18th International Conference on Electrical Contacts.

[43]  J. Haidar,et al.  A method for the measurement of the cathode surface temperature for a high‐current free‐burning arc , 1993 .

[44]  Min-Xian Zhang,et al.  The solubility of gases in liquid metals and alloys , 1988 .

[45]  C. Knight.  Theoretical Modeling of Rapid Surface Vaporization with Back Pressure , 1979 .

[46]  A. E. Guile,et al.  Arc-electrode phenomena , 1971 .