Free-cutting brass alloy and manufacturing method therefor

Abstract

Provided are a free-cutting brass alloy and a manufacturing method therefor. The copper alloy comprises, by weight percentage: 62% - 65% of copper, 0.01% - 0.15% of iron, 0.2% - 0.6% of tin, 0.2% - 0.6% of aluminum, 0.02% - 0.2% of nickel, 0.06% - 0.15% of arsenic, 0.3% - 1.2% of bismuth, 0.03% - 0.15% of antimony, 0.0005% - 0.0025% of boron, 34% - 37% of zinc and 0.01% - 0.1% of a mixed rare earth modificator.

Description

Technical field [0001] The invention relates to the field of brass alloys, in particular to a free-cutting brass alloy and a manufacturing method thereof. Background technique [0002] Lead-free free-cutting brass is a brass alloy based on copper and zinc with a certain amount of bismuth, tin, aluminum, antimony, and arsenic. Substituting bismuth for lead, its cutting performance is equivalent to or close to that of lead brass, and its resistance to dezincification reaches AS2345 standard, excellent forging processing performance. However, the bismuth brass materials that have been developed and used are mainly cast rods and extruded rods. The main reason is that the solid solubility of bismuth in copper is extremely low, and component segregation is easy to occur during the smelting process, which affects the internal quality of the ingot. Bismuth is often distributed as a brittle film on the grain boundaries of brass, which produces both hot brittleness and cold brittleness, w...

AI Technical Summary

Problems solved by technology

However, the bismuth brass materials that have been developed and used are mainly cast rods and extruded rods, mainly because the solid solubility of bismuth in copper is extremely low, and the composition segregation is easy to occur during the melting process, which affects the internal quality of the ingot.

Bismuth is often distributed on the brass grain boundary in the form of a brittle film, which produces both hot brittleness and cold brittleness, which is easy to cause cracking during cold and hot processing, and the lack of dezincification resistance limits its application.