摘要
The effect of mischmetal addition on lead segregation in high lead bronze(grade ZQPb25-5)is studied in this paper.The testing results confirm that 0.5 to 1.0% misehmetal addition can effectively prevent lead from gravity and inverse segregation.The results of preventing lead from segregation respectively by mischmetal and nickel are also compared in the paper.The mischmetal addition in high lead bronze is distributed in the copper matrix mainly in the form of a compound which promotes early precipitation and refinement of α-dendrites, thus restraining the Pb-rich melt from either sinking to the bottom or escaping to the surface layer of the casting.As a result,the tendency of lead segregation is significantly decreased.Proper addition of mischmetal can also improve the mechanical properties,especially the ductility of high lead bronze.In addition,the contents of tin in high lead bronze can partially be substituted by mischmetal addition.
The effect of mischmetal addition on lead segregation in high lead bronze(grade ZQPb25-5)is studied in this paper.The testing results confirm that 0.5 to 1.0% misehmetal addition can effectively prevent lead from gravity and inverse segregation.The results of preventing lead from segregation respectively by mischmetal and nickel are also compared in the paper.The mischmetal addition in high lead bronze is distributed in the copper matrix mainly in the form of a compound which promotes early precipitation and refinement of α-dendrites, thus restraining the Pb-rich melt from either sinking to the bottom or escaping to the surface layer of the casting.As a result,the tendency of lead segregation is significantly decreased.Proper addition of mischmetal can also improve the mechanical properties,especially the ductility of high lead bronze.In addition,the contents of tin in high lead bronze can partially be substituted by mischmetal addition.
