Ball Milling Time Effect on Tungsten copper Electrode Powder Granularity

High speed and high frequency of impact by high energy planetary ball milling grinding media, which is beneficial for energy conversion and the transport and diffusion of atoms, molecular and plasma. Some experiments show that the milling strength has an important influence on the formation of mechanically alloyed amorphous. When the strength is low, the powder is formed into an amorphous longer, even unable to form an amorphous; while the strength is high, forming an amorphous time will be greatly shortened, and help broaden the scope of amorphous components, but continued milling when it would make already amorphous powder re-crystallization of the formation of a new phase. High-energy ball milling easily forms a stable compound rather than amorphous. Ball milling time directly affects the composition and purity of powder production.

The amorphous and crystalline transformation of some metals or alloys only within a certain time, the milling time is too short too small to gather energy inside the material damage which binds covalently; the long ball milling time will cause other changes. In the process of grinding, due to the friction and compacts of powder, the self temperature of powder, partial temperature increasing is beneficial for solid-phase reaction. But overall temperature rise will reunite furniture material and adhesion between the ball and the cylinder wall and the milling of certain organic compounds, high temperature will cause it to break down and so on.

Furthermore, under the effect of compaction, rolling and cold heading between grinding ball or inside wall. With the increasing ball milling time, tungsten copper (W-Cu) powder will form schistose composite powder under plastic deformation and cold welding. Since microscopic strain hardening and increased plastic composite powder decreased, resulting in its fracture refinement, the particles have a break after constantly repeated cold welding and re-fracture, mixing tungsten copper alloy electrode particles are more uniform composite powder becomes more small homogeneous particles.

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