leadantimony

Leadantimony refers to a binary alloy of lead (Pb) and antimony (Sb). The addition of antimony to lead modifies the metal’s mechanical properties, producing a harder, stronger, and more creep-resistant material than pure lead, while preserving some ductility compared to other hard lead alloys. The exact behavior depends on the antimony content and heat treatment.

Composition and ranges are typically described by weight percent of antimony. Common industrial ranges span from about 2% to 12% Sb, with lower levels used where modest strength gains are sufficient and higher levels used for greater hardness. In lead-acid battery technology, antimony is often added in small to moderate amounts (roughly around 4–6% Sb) to improve grid strength and resistance to deformation during cycling. Bullet and bearing alloys sometimes employ higher Sb content to increase hardness and wear resistance. Increasing antimony generally raises hardness and tensile strength but reduces ductility and machinability, and it can raise brittleness and the alloy’s melting point.

Processing involves melting lead and then alloying in antimony before casting or forming. The alloy can be cast, rolled, or formed into various shapes. Thorough homogenization is typically used to distribute antimony evenly and to minimize phase segregation.

Safety and environmental considerations are important. Lead and antimony compounds are toxic, exposure should be avoided, and appropriate engineering controls, handling practices, and waste management are required. Recycling of lead–antimony alloys, notably from spent lead-acid batteries, is common, with attention to safe recovery and emissions controls.