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[资源]
Arc erosion behavior of the Al2O3-Cu/(W, Cr) electrical contacts
Arc erosion behavior of the Al2O3-Cu/(W, Cr) electrical contacts
弥散铜-(W,Cr)电接触复合材料电弧侵蚀
Al2O3-Cu/(25)W(5)Cr and Al2O3-Cu/(35)W(5)Cr electrical contact materials were fabricated by vacuum hot-
pressing sintering and internal oxidation. The relative density, electrical conductivity, and Brinell hardness were
measured. The microstructure was analyzed by scanning electron microscopy and transmission electron mi-
croscopy. JF04C electrical contact testing apparatus were used to investigate the electrical contact performance
of composites. Arc erosion morphologies were analyzed by scanning electron microscopy and three-dimensional
profilometer. The material transfer as well as electrical contact performance were studied during contact make
and break operations at 30 V DC with current between 10 and 30 A. It indicates that the nano-Al2O3 particles
pinned dislocations. Material transfers from the cathode to the anode. With the melting, evaporation, and
sputtering of Cu during arcing, W particles gather and generate needle-shaped skeletons. Finally, liquid droplets,
needle-like structures, craters, and bulges were formed on electrode surfaces after arc erosion. Furthermore, their
quantity and morphology are affected by tungsten content. When the content of W in the dispersed copper
matrix increases from 25 wt% to 35 wt%, welding force is reduced during the steady operations. In addition,
when the arc duration is greater than 8.86ms, the Al2O3-Cu/(35)W(5)Cr contact material has a shorter average
arc duration than Al2O3-Cu/(25)W(5)Cr at the same arc energy. |
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