Is beryllium copper alloy toxic? Classification and properties of beryllium copper alloys?
Beryllium copper, also known as beryllium bronze, is the "king of elasticity" in copper alloys. After solution aging heat treatment, products with high strength and high electrical conductivity can be obtained. High-strength cast beryllium bronze alloy, after heat treatment, not only has high strength, high hardness, but also has the advantages of wear resistance and corrosion resistance, excellent casting performance, beryllium bronze alloy is suitable for the manufacture of various molds, explosion-proof safety tools, wear-resistant Components such as cams, gears, worm gears, bearings, etc.
Classification of beryllium copper alloys
Beryllium bronzes are divided into two categories. According to the alloy composition, the beryllium bronze with a beryllium content of 0.2% to 0.6% is a high-conductivity (electrical, thermal) beryllium bronze; the beryllium content of 1.6% to 2.0% is a high-strength beryllium bronze. According to the manufacturing and forming process, it can be divided into cast beryllium bronze and deformed beryllium bronze. The internationally used beryllium bronze alloy grades are headed by C. Deformed beryllium bronze has two categories: C17000, C17200 (high-strength beryllium bronze) and C17500 (high-conductivity beryllium bronze). The corresponding cast beryllium bronzes are C82000, C82200 (high-conductivity cast beryllium copper) and C82400, C82500, C82600, C82800 (high-strength wear-resistant cast beryllium copper). The largest beryllium copper alloy manufacturer in the world is Brush Wellman Company in the United States, whose corporate standards correspond to international standards and are authoritative. The history of China's production of beryllium bronze is almost synchronized with that of the former Soviet Union, the United States and other countries, but the only grades listed in the national standard are high-strength beryllium bronze QBe1.9, QBe2.0, and QBe1.7. Other high conductivity beryllium bronzes or cast beryllium bronzes have been put into large-scale production according to the needs of the development of the petroleum industry and the defense industry.
Properties of beryllium copper alloys
Beryllium bronze has good comprehensive properties. Its mechanical properties, namely strength, hardness, wear resistance and fatigue resistance, rank first among copper alloys. Its electrical conductivity, thermal conductivity, non-magnetic, anti-spark and other properties cannot be compared with other copper materials. The strength and conductivity of beryllium bronze in the solid solution soft state are at the lowest value. After work hardening, the strength is increased, but the conductivity is still the lowest value. After aging heat treatment, its strength and electrical conductivity increased significantly.
The machining properties, welding properties and polishing properties of beryllium bronze are similar to those of general high copper alloys. In order to improve the machining performance of the alloy and meet the precision requirements of precision parts, countries have developed a high-strength beryllium bronze (C17300) containing 0.2% to 0.6% lead. Its properties are equivalent to C17200, but the cutting coefficient of the alloy is Increased from 20% to 60% (free-cutting brass is 100%).
Is beryllium copper alloy toxic?
Under normal circumstances, beryllium copper is not toxic. Copper beryllium should not be in direct contact with human skin, otherwise it will cause oxidation of copper beryllium. Wear gloves when touching, and then wash your hands after touching, as long as it is not in a high temperature state, no toxins will be produced.
Beryllium is highly toxic and is a carcinogenic metal; nickel metal is non-toxic and chemically stable; copper metal is non-toxic and ion toxic.
New copper alloy material replaces beryllium copper alloy
The beryllium copper alloy contains the highly toxic substance beryllium, and the stress relaxation rate increases sharply in the environment higher than 150 ℃, which can easily lead to the change of the contact pressure of the elastic components in the working state, resulting in the failure of the connector. The development of new environmentally friendly and ultra-high strength, high stress relaxation resistance, excellent formability, and high reliability of conductive elastic copper alloys has become a research hotspot in elastic materials. Alloys such as Cu-Ni-Mn, Cu-Ti and Cu-Ni-Sn are aging-strengthened alloys. After deformation heat treatment, they can obtain strength and elastic properties comparable to beryllium copper alloys, as well as superior corrosion resistance and resistance. Stress relaxation properties. These alloys have been successively researched and developed by French, American, Japanese and other companies, and have partially replaced the industrial application of beryllium copper alloys. Some domestic copper processing enterprises are trial-producing Cu-Ti alloy products, but the key processing and preparation technology for large-scale production still needs to be fully broken through, resulting in the inability of existing Cu-Ti alloy materials to achieve self-sufficiency.