Vacuum arc characteristics on nanocrystalline CuCr alloys

 Vacuum arcs generated on nanocrystalline CuCr5 alloys were observed by a digital high-speed video camera. Experimental results show that nanosized Cr particles have strong influence on arc characteristics. The arcs are much more stable on nanocrystalline CuCr5 alloys and the chopping current is about 0.8 A, which is much lower than that on coarse crystalline CuCr5 alloys. Spots can directionally move a long distance on nanocrystalline CuCr alloy whereas the spot motion is totally random walk on Cr particles for coarse crystalline CuCr alloy.