Leadless free-cutting slicon graphite brass

Abstract

The invention relates to lead-free free-cutting silicon graphite brass, which belongs to the technical field of metal material manufacturing. The mass fractions of each alloying element of the brass are respectively copper 58.0-62.0 %, silicon 0.1-3.5% and graphite 0.1-3.5%, the summation of the mass fraction of the silicon and the mass fraction of the graphite is 1.0-4.0%, allowance is zinc, and the total amount of impurity is no more than 0.05%. The graphite brass of the invention adopts the silicon and the graphite elements to replace lead element which pollutes environment and is very harmful to human health on the basis of existing free-cutting lead brass and aiming at the concrete requimrents of the material under using environment and using conditions, which realizes the lead-free soldering of the free-cutting lead brass. The brass has excellent cutting performance and thermoplasticity, the hot extrusion ratio reaches more than 80, cryogenic brittleness phenomenon does not appear, and the brass is applied in the fields of electronic devices, water heating bathroom facilities, constructional elements and the like and replaces the existing free-cutting lead brass.

Description

technical field [0001] The invention is a metal material, especially a lead-free free-cutting silicon graphite brass. Background technique [0002] Lead-containing copper alloy has the properties of easy cutting and physical, chemical and mechanical properties, and is a kind of copper alloy widely used. At present, the annual output of only lead brass in my country is about 500,000 tons. However, this kind of copper alloy will cause environmental pollution and endanger human health during production and use, so its application is increasingly restricted. Since August 6, 1998, the United States has required the leaching of lead in the drinking water supply system to be within 1.1×10 -3 % or less, Japan stipulated that the lead content in drinking water should be less than 0.03mg / L in 2003. The European Union's lead-free directive has come into force on July 1, 2006. Correspondingly, our country also began to implement lead-free from March 1, 2007. Lead does not dissolve ...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to effectively solve the problems of lead brass polluting the environment and the high content of bismuth brass, and provide a low-cost and high-performance lead-free free-cutting silicon graphite for the fields of electronic devices, plumbing and sanitary ware, and structural parts. brass