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 grav...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.展开更多
本文测定了含稀土纯 Al 及 Al-Mn 合金中球状稀土相的形貌,组成及分布。结果表明,适量稀土可使 Al 中多角形块状化合物球化,在轧制过程中球状稀土相不变形,不聚集,均匀分布在晶内。稀土改变了 Al 基体中杂质元素的微区分布规律,导致 Fe,...本文测定了含稀土纯 Al 及 Al-Mn 合金中球状稀土相的形貌,组成及分布。结果表明,适量稀土可使 Al 中多角形块状化合物球化,在轧制过程中球状稀土相不变形,不聚集,均匀分布在晶内。稀土改变了 Al 基体中杂质元素的微区分布规律,导致 Fe,Si 等元素由晶界向球状相迁移,晶界获得净化。分析了球状稀土相形成及晶界净化的原因。展开更多
文摘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.
文摘本文测定了含稀土纯 Al 及 Al-Mn 合金中球状稀土相的形貌,组成及分布。结果表明,适量稀土可使 Al 中多角形块状化合物球化,在轧制过程中球状稀土相不变形,不聚集,均匀分布在晶内。稀土改变了 Al 基体中杂质元素的微区分布规律,导致 Fe,Si 等元素由晶界向球状相迁移,晶界获得净化。分析了球状稀土相形成及晶界净化的原因。
