The invention discloses a method for preparing high-purity
metal through
electron beam melting, which is characterized in that specific alloying
metal powder is added in a cold pressing stage for powdery
metal raw materials, so that the alloying
metal powder is firstly melted to form a
liquid phase in the initial stage of
electron beam melting, and densification, bonding and integral forming of main
metal powder are realized; and a necessary high-temperature
sintering step in a traditional process is omitted. And in the high-temperature
electron beam melting stage, the impurities are preferentially distributed into a second phase rich in alloying metal through the affinity interaction between the alloying metal and the target impurities and the limited mutual
dissolution characteristic of the alloying metal and the target impurities in the melt. And in combination with the
directional solidification process from bottom to top, the second phase rich in impurities is concentrated and enriched at the solidification
tail end, and finally an
impurity layer capable of being integrally
cut off is formed at the top of the
crucible. According to the method, the thermodynamic activity reduction and solidification segregation behaviors of the impurities are enhanced, the removal efficiency of the impurities difficult to separate can be remarkably improved, the removal rate of the impurities in a typical
system can reach 95% or above, and the purity of main metal can be improved to 99.999% or above.