Pure copper is also known as copper, copper alloy is divided into brass, bronze, white copper.
Brass is divided into ordinary brass (binary brass), special brass (multiple brass);
Bronze is divided into tin bronze, aluminum bronze, beryllium bronze, silicon bronze, lead bronze;
White copper is divided into ordinary white copper and special white copper.
3. Pure copper. Also known as red copper, purity is greater than 99%, divided into ordinary pure copper, deoxidized copper, oxygen-free copper and special copper. Excellent electrical conductivity, thermal conductivity, non-magnetic, plastic. It has good corrosion resistance in atmosphere and fresh water, but poor in sea water.
3.1 Classification.
Ordinary pure copper: high oxygen content, can not be heated in the reducing medium, so as to avoid hydrogen embrittlement, mainly used for conductive and thermal components.
Deoxidized copper: Residual deoxidizer elements (P, Mn), strongly reduce the electrical conductivity of copper, should only be used as structural materials.
Oxygen-free copper: Oxygen and impurity content is very low, mainly used in electric vacuum devices.
Special copper: contains different trace amounts of specific elements, such As containing AS, Ag, Te and dispersion copper, mainly used in conductive structural parts.
3.2 Properties.
3.2.1 Impurity elements will reduce the electrical and thermal conductivity of pure copper.
3.2.2 Pb and Bi will increase the thermal brittleness, which is easy to crack during hot processing, and the addition of Ca, Ce and Zr to form refractory compounds can eliminate the effect; S, O will increase cold brittleness, easy to break during cold processing, O in 0.02-0.1%, S in 0.005-0.01%.
3.2.3 Hydrogen disease (caused by oxygen).
3.2.4 Role of oxygen: cause hydrogen embrittlement and cold embrittlement.
3.3 Brand. Represented by T (Tong), No. 1-4 copper, T1, T2, T3, T4, the increase in the number indicates a decline in purity. Copper with an oxygen content of less than 0.01% is called oxygen-free copper and is indicated by TU1 and TU2.
4. Brass. It is divided into ordinary brass (binary brass) and special brass (multi-component brass).
Common brass: Cu-Zn binary alloy.
Code H+Cu%, such as H68 indicates a copper-zinc alloy containing Cu68%.
Features, good corrosion resistance, the higher the zinc content, the cheaper, up to 46%; The more zinc content, the more likely to stress corrosion rupture, adding Si and As can reduce stress corrosion rupture.
Six phases.
Typical brass and uses: 73 brass, H70, manufacturing shell brass, also known as shell brass; Twenty-one brass, containing about 65% copper, can be made of copper rod, copper wire, copper sheet, copper pipe, wood screws, springs, etc. 64 brass, containing about 60% copper, manufacturing heating pipes, copper sheets, copper wires, copper rods and so on.
5. Bronze. Divided into tin bronze, aluminum bronze, beryllium bronze, phosphorus bronze, silicon bronze and so on.
5.1 brand. Q+ the sign and mass fraction of the main plus element + the mass fraction of other elements. For example, QSn4-3 indicates tin bronze containing 4% tin and 3% zinc.
5.2 Tin bronze. Tin content 3~14%, the higher the tin content, the greater the strength of the alloy hardness. The price of tin is higher.
Casting performance: small volume shrinkage.
Mechanical properties: Tin <6%, suitable for cold deformation, tin 6~7% suitable for hot processing; Tin 10~14% suitable for casting alloys.
Corrosion resistance: better than copper, brass.
Multi-component tin bronze: Add Zn, P, Pb, Ni, etc. P can effectively improve the mechanical properties of the alloy, especially the elastic limit and fatigue limit, suitable for spring; Zn enhances casting fluidity and compactness; Pb improves machinability and wear resistance; Zr, B, V, Ti grain refinement;
Commonly used tin bronze: QSn4-3, QSn6.5-0.4, ZCuSn10Pb1, etc., for the manufacture of elastic components, wear-resistant parts, diamagnetic and corrosion-resistant parts, such as springs, bearings, gears, turbines, washers, etc.
Mechanical tin bronze: commonly known as gun copper, including Sn10%, the production of gear, valves, propellers and other corrosion and wear resistant devices.
Bearing tin bronze: including Sn12~15%, railway axle and other low speed heavy load bearings.
Tin bronze: containing Sn4~10%, good ductility, excellent casting.
Tin bronze: containing Sn20~32%, the less impurities, the clearer the sound.
Bronzes: Bronze statues and home decoration bronze, Cu80~90%, Sn2~8%, Zn1~12%, Pb1~3%, containing Zn to improve solution fluidity, casting surface lines are clear.
Mirror copper: 2/3Cu, 1/3Sn, ancient copper mirror. Scientific instruments can be made by adding a small amount of Ni and As.
5.3 Aluminum bronze. Aluminum <11.5%. The price of tin is high, the price of aluminum is cheap, and some tin bronze is replaced by aluminum bronze.
Casting performance: good fluidity, large volume shrinkage, alumina inclusion, easy to crack.
Mechanical properties: Impact without spark. With the increase of Al content, the strength and hardness increase and the plasticity decrease. Al5~8%, cold processing can be hot processing, Al8~11%, poor fluidity, used as casting alloy.
Corrosion resistance: The surface forms a dense oxide film, corrosion resistance is better than tin bronze.
Multicomponent aluminum bronze: add Fe, Ni, Mn, etc. Fe refines grains to avoid spontaneous tempering brittleness, Mn improves strength to avoid tempering brittleness, Ni improves heat resistance and corrosion resistance.
5.4 Beryllium bronze. Beryllium is more expensive than silver.
Features: high strength and high hardness, high fatigue limit and elastic limit; Corrosion-resistant, wear-resistant, cold, alkaline, good electrical and thermal conductivity; Impact without spark. Often used as advanced precision elastic components and special wear-resistant components, used as mines, oil refineries and other impact sparkless occasions.
Beryllium bronze often adds Ni0.2-0.5%, the practical Cu-Be-Ni ternary alloy, a small amount of Ni to improve elasticity, strength, wear resistance and corrosion resistance.
Fe, Co, Ni and Mg enhance aging and refine grain. Strictly control the content of impurity elements P and Pb.
Corrosion and wear resistance: QBe2, QBe1, fresh water and seawater can be made of springs, wear-resistant bearings, explosion-proof tools, etc.
6. White copper. Copper with nickel as the main alloying element. It is divided into ordinary white copper and special white copper according to chemical composition. Ordinary white copper contains only copper and nickel. Special white copper is ordinary white copper on the basis of adding Zn, Mn, Al, Fe, Pb, etc., respectively called zinc white copper, manganese white copper, aluminum white copper, iron white copper, lead white copper and so on.
Code: B+ Nickel content. B19 means ordinary white copper containing Ni19%, BMn40-1.5 means electrical white copper containing Ni40% and Mn1.5%.
White copper by application classification, structural white copper and electrical white copper.
6.1 Cu-Ni alloy. Containing Ni3-30%, high strength, high corrosion resistance, high pressure, low temperature structural material.
6.2 Special white copper. Improve the aging strength. Aluminum white copper, excellent high temperature performance, suitable for high temperature parts of internal combustion engines; Silicon white copper, good elongation and conductivity, suitable for high-strength span power lines, trolley overhead wires, etc.; Zinc white copper, good heat resistance, corrosion resistance and fatigue resistance, small resistance temperature coefficient, making spring or thermoelectric materials.
6.3 Structural white copper. Including ordinary white copper, iron white copper, zinc white copper, aluminum white copper, with good corrosion resistance, processing properties. Used in the production of condensers, heat exchangers, medical instruments, corrosion-resistant parts, artwork and so on.
6.4 Electrician’s white copper. Including ordinary white copper, manganese white copper, with high resistance, high thermal potential and low resistance temperature coefficient, used to compensate wires, thermocouples, resistance instruments and heaters.
