A new technique for preventing lead segregation in aluminium bearing alloys

Abstract

The authors have studied the characteristics of lead segregation in an aluminium alloy and, as a result, a new technique for the uniform dispersion of lead in such an alloy has been developed. Using this method, which involves the addition of an active flux containing potassium into the molten alloy, lead segregation, which represents a critical problem in the production of aluminium alloys containing lead, has been eliminated. This paper discusses the effect of the new technique on lead segregation and the effects of the flux on the structure of the alloy under test. The rationale behind the melting and casting practice developed is discussed from a basis of macrosegregation theory and the thermo-physical properties of lead and aluminium.

Keywords:

• aluminium base alloys
• Al-Cu alloys
• lead segregation
• potassium flux
• melt technique