We have developed a direct-current H electric arc plasma device to systematically research the effects of H/Ar ratio

electric current and pressure on the production rate

structure and spheroidalization of nano-Ni powder and nano-Cu powder by orthogonal testing. The results show that the device not only can prepare nano-Ni powder and nano-Cu powder but also can greatly raise the product rate

where maximum product rate is increased by 24 times for Ni powder and by 203.7 times for Cu powder. Significant orders influencing product rate of two powder is H2/Ar ratio

then current

then pressure

and orders influencing average diameters of Ni powder is H2/Ar

then pressure

then current

and orders influencing average diameters of Cu powder is pressure

then H2/Ar

then current. Both prepared nano-Ni powder ranging in 20

6

5 nm in average diameter and nano-Cu powder ranging in 23

1

41 nm in average diameter are polygonal crystal

where impurities is absent in prepared Ni powder and there exists CuO in prepared Cu powder. Cooling condition in cavity of the device has the important effects on formation and distribution of powder.