Properties of beryllium copper Alloy
1. Copper has good electrical and thermal conductivity, sufficient corrosion resistance in the atmosphere and many media, and has a series of characteristics such as sufficient strength and good plasticity. According to the different alloying elements added to copper, copper alloys are usually divided into four categories: copper (pure copper), brass, bronze and white copper.
2. Although beryllium is a rare light metal, with the development of science and technology and industry, its application has become wider and wider. The three main forms of beryllium metals, alloys, and oxides are widely used in atomic energy, rockets, missiles, satellites, aviation, aerospace, electronics, instrumentation, petrochemicals, ceramics and other technical fields.The high-tech fields have been applied earlier, especially in recent The scope of industrial and civilian use has expanded rapidly in the year, and the amount has soared, which has brought development opportunities to the beryllium industry.
3. Beryllium is an ideal thermal shielding material for aerospace. Its heat absorption capacity is 2.5 times that of aluminum and 4.5 times that of titanium. At 20 ° C, the specific gravity is 1.84t / m3, and the melting point is 1285 ° C. Beryllium is used as a structural material in missiles, satellites, and aircraft, which can reduce weight and increase travel. Also used in intercontinental missile adapter shells, navigation control bins; satellite high-frequency antenna tubes, power conversion devices, bearings, antenna tube brackets; beryllium rudder compressor disks, disc controllers, gyroscopes on aircraft; rocket fuel, Spacecraft heat-absorbing outer cover, solar cell, reflector moderator in atomic reactor, diffused phase combustion matrix, etc.
4. Beryllium bronze (Beryllium copper alloy): At 20 ℃, the specific gravity is 8.26t / m3, the melting point is 850 ～ 1000 ℃, and after the solution aging heat treatment, high strength and high conductivity products can be obtained. Beryllium copper high-strength cast alloy not only has high strength and high hardness after heat treatment. And has the advantages of non-magnetic, wear-resistant, corrosion-resistant, excellent casting performance, suitable for manufacturing various molds, explosion-proof safety tools, wear-resistant parts such as cams, gears, worm gears, bearings, mold manufacturing, etc.
5.Beryllium copper highly conductive casting alloy has high electrical conductivity and thermal conductivity after heat treatment.It is suitable for manufacturing switch parts, strong contact and similar current-carrying components, making resistance welding clamps, electrode materials and plastic molds, and hydropower. Inner sleeve of continuous casting machine mold.
Brass alloy properties
1. Ordinary brass is a copper-zinc binary alloy, and its zinc content varies widely, so its room temperature structure is also very different. According to the Cu-Zn binary state diagram, there are three types of brass at room temperature: brass with zinc content below 35%, and the microstructure at room temperature consists of a single-phase α solid solution, called α brass; zinc contains The amount of brass in the range of 36% to 46%, the microstructure at room temperature is composed of (α + β) two phases, called (α + β) brass (two-phase brass); the zinc content exceeds 46 % ～ 50% brass, the microstructure at room temperature is only composed of β phase, which is called β brass.
2. Alpha single-phase brass (from H96 to H65) has good plasticity and can withstand hot and cold machining, but alpha single-phase brass is prone to medium-temperature brittleness during hot machining such as forging. The specific temperature range varies with the Zn content. And some changes, generally between 200 ~ 700 ℃. Therefore, the temperature during hot working should be higher than 700 ° C. The reason for the single-phase α-brass medium temperature brittleness zone is mainly due to the existence of two ordered compounds Cu3Zn and Cu9Zn in the α-phase region of Cu-Zn alloy system. The orderly transformation occurs during heating at low and medium temperatures, making the alloy brittle; There are trace amounts of harmful impurities of lead and bismuth in the alloy, which form a low melting point eutectic film with copper and are distributed on the grain boundaries. Intercrystalline cracking occurs during hot machining. Practice has shown that adding a small amount of cerium can effectively eliminate the medium temperature brittleness.
3. In the two-phase brass (from H63 to H59), in addition to the α phase with good plasticity, β solid solution based on the electronic compound CuZn also appeared. The β phase has high plasticity at high temperature, while the β ′ phase (ordered solid solution) at low temperature is hard and brittle. Therefore, (α + β) brass should be forged in the hot state. Due to its hard and brittle properties, β brass with a zinc content greater than 46% to 50% cannot be subjected to pressure machining.
4. The structure of complex brass can be calculated based on the "zinc equivalent coefficient" of elements added to brass. Because a small amount of other alloying elements are added to the copper-zinc alloy, the α / (α + β) phase region in the Cu-Zn state diagram is usually moved to the left or right. Therefore, the structure of special brass is usually equivalent to the structure of increasing or decreasing the zinc content in ordinary brass. For example, the structure after adding 1% silicon to the Cu-Zn alloy is equivalent to the alloy structure that adds 10% zinc to the Cu-Zn alloy. So the "zinc equivalent" of silicon is 10. The "zinc equivalent coefficient" of silicon is the largest, which makes the α / (α + β) phase boundary in the Cu-Zn system move significantly to the copper side, that is, the α phase region is strongly reduced. The "zinc equivalent coefficient" of nickel is negative, that is, the α-phase region is enlarged.
5. The α phase and β phase in special brass are multiple complex solid solutions, and their strengthening effect is large, while the α and β phases in ordinary brass are simple Cu-Zn solid solutions, and their strengthening effect is low. Although the zinc equivalents are equivalent, the properties of the multiple solid solution and the simple binary solid solution are different. Therefore, a small amount of multiple strengthening is a way to improve the properties of the alloy.
What are the classifications of beryllium copper?
1. C17200: wear-resistant and high-temperature beryllium bronze
2.QBE2: High hardness and wear-resistant beryllium bronze
3. C17300: Easy turning beryllium bronze
4.C17500: Welding Beryllium Cobalt Copper
5.C17510: High conductivity and high temperature resistant beryllium nickel copper
What are the classifications of brass?
1. Lead brass: Lead is practically insoluble in brass and is distributed on the grain boundaries in a free particle state. There are two types of lead brass: α and (α + β). Alpha lead brass has the harmful effects of lead and low temperature plasticity, so it can only be cold deformed or hot extruded. (Α + β) lead brass has good plasticity at high temperatures and can be forged.
2. Tin-copper copper: The addition of tin to brass can obviously improve the heat resistance of the alloy, especially the ability to resist seawater corrosion. Therefore, tin-brass is called "Navy Brass". Tin can be dissolved in a copper-based solid solution, and it can strengthen the solid solution. However, with the increase of tin content, brittle r-phase (CuZnSn compound) appears in the alloy, which is not conducive to plastic deformation of the alloy. Therefore, the tin content of tin-brass is generally in the range of 0.5% to 1.5%.
Commonly used tin brass are HSn70-1, HSn62-1, HSn60-1 and so on. The former is an alpha alloy, which has high plasticity and can be cold and hot pressed. The latter two types of alloys have (α + β) two-phase structure, and a small amount of r phase often appears. The plasticity at room temperature is not high, and it can only be deformed in the hot state.
3. Manganese brass: Manganese has greater solubility in solid brass. Adding 1% to 4% of manganese in brass can significantly improve the strength and corrosion resistance of the alloy without reducing its plasticity.
Manganese brass has (α + β) structure, and HMn58-2 is commonly used. The pressure machining performance under cold and hot conditions is quite good.
4. Iron brass: In iron brass, iron is precipitated as fine particles of iron-rich phase, which is used as crystal nucleus to refine the grains, and can prevent the recrystallized grains from growing, thereby improving the mechanical properties and cnc machining process performance of the alloy. The iron content in iron brass is usually less than 1.5%, and its structure is (α + β). It has high strength and toughness, good plasticity at high temperature, and deformable in cold state. The commonly used grade is Hfe59-1-1.
5. Nickel brass: Nickel and copper can form a continuous solid solution, which significantly enlarges the α phase region. Adding nickel to brass can significantly improve the corrosion resistance of brass in the atmosphere and seawater. Nickel can also increase the recrystallization temperature of brass and promote the formation of finer grains. HNi65-5 nickel brass has a single-phase α structure, has good plasticity at room temperature, and can also be deformed in the hot state, but the content of lead must be strictly controlled. Restraint will seriously deteriorate the hot workability of the alloy.