An Investigation For The Effects Of Electro Pulse Modification On The Constituent Phases Of Silicon Brass

At present, the (β+γ) two-phase silicon brass is less used in life, because the star shape ofγ phase which increases the adhesion of tool and substrate, and the coarse γ phase seriouslyisolates the matrix. In this paper, HSi59-2.5silicon brass was studied, applied the electricpulse modification technology to change the phase of silicon brass, in order to enhance theoverall properties. It is meaningful to apply the electric pulse modification technology toenhance the properties of HSi59-2.5silicon brass.HSi59-2.5silicon brass was disposed by electric pulse with different parameters,discussed the changes of silicon brass which included the shape, distribution, quantity andtransitive relation, discussed the effects of constituent phases of silicon brass under electricpulse with different cooling methods. The results showed that the γ phase uniformly dispersedin the matrix of β-phase. The size of γ phase decreased with addition of pulse frequency, from44.6μm to20.43μm(1000V,30s,20Hz). The volume fraction firstly increased and thendecreased, it reached the minimum of49.94%with8Hz. The matrix hardness increased from325.4HV to365.6HV. The optimal parameters were1000V,30s,8Hz, the optimal coolingmethod was metal cooling.Through the discussion about relationship between transferring coefficients of spacing,length/width, distribution of γ phase and pulse frequency, the spacing transferring coefficientФ is inverse proportional to the pulse frequency, the distribution transferring coefficient η isproportional to the pulse frequency. When the pulse parameter are1000V,30s,8Hz, theoptimal value of length/width is1.12, the shape of γ phase was the most blunt. These issuesexplain the effects of electropulse modification on the constituent phases of silicon brass,improves the constituent phases of the (β+γ) two-phase silicon brass. It has certain guidingsignificance to improve the cutting property of HSi59-2.5silicon brass.