Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The ar...Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes major erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.展开更多
A new type of Cu-La2O3 composite was fabricated by internal oxidation method using powder metallurgy.Sliding wear behavior of the Cu-La2O3 composite was studied on a pin-on-disc wear tester under various electrical cu...A new type of Cu-La2O3 composite was fabricated by internal oxidation method using powder metallurgy.Sliding wear behavior of the Cu-La2O3 composite was studied on a pin-on-disc wear tester under various electrical currents and applied loads.The worn surfaces were characterized using scanning electron microscopy and energy dispersive spectroscopy to probe the wear mechanisms.The results indicated that applied load had a significant effect on the wear rate of the Cu-La2O3 composite pins.The wear rate displayed the minimum value at the load of 50 N during electrical sliding processes.The corresponding wear mechanism was identified to be adhesive wear,abrasive wear,oxidation wear and arc erosion.展开更多
基金Barnbrook Systems, UK for their support of this work
文摘Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes major erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.
基金supported by the National Natural Science Foundation of China(50731005)
文摘A new type of Cu-La2O3 composite was fabricated by internal oxidation method using powder metallurgy.Sliding wear behavior of the Cu-La2O3 composite was studied on a pin-on-disc wear tester under various electrical currents and applied loads.The worn surfaces were characterized using scanning electron microscopy and energy dispersive spectroscopy to probe the wear mechanisms.The results indicated that applied load had a significant effect on the wear rate of the Cu-La2O3 composite pins.The wear rate displayed the minimum value at the load of 50 N during electrical sliding processes.The corresponding wear mechanism was identified to be adhesive wear,abrasive wear,oxidation wear and arc erosion.
