Patent ID: 7695578

Claim:
A bronze alloy consisting of 5.0 to 10.0 weight % of Zn, 2.8 to 5.0 weight % of Sn, 0.25 to 3.0 weight % of Bi, 0<Se<0.35 weight % of Se, less than 0.5 weight % of P, the balance of Cu and unavoidable impurities, said bronze alloy having soundness improved during a course of solidification of the bronze alloy by crystallizing ZnSe that is an intermetallic compound capable of solidifying within a range of solidifying temperature as a temperature region between a solidus line and a liquidus line surpassing the solidus line in dendrite gaps of the alloy, thereby suppressing migration of a solute and consequently effecting dispersion of microporosities and by utilizing the crystallization of the intermetallic compound ZnSe for suppressing segregation of Bi that is a low melting metal capable of solidifying at a temperature falling short of the solidifying temperature of the bronze alloy and relying on the Bi to enter the microporosities and undergo dispersed crystallization and consequently suppress occurrence of microporosities.