Mechanical Knowledge

The difference and application of various copper

The types of copper are as follows:

1. Brass
2. Purple copper
3. Pure copper
4. Aluminum bronze (special aluminum bronze)
5. Tin bronze
6. Beryllium bronze
7. Sintered bronze

All kinds of copper, their application and the difference between them

1. Brass

Brass is an alloy composed of copper and zinc. Brass only composed of copper and zinc is called ordinary brass. If composed of more than two elements, it is called special brass. Brass has strong wear resistance, and brass is often used to manufacture valves, water pipes, connecting pipes for internal and external air conditioners and radiators.


2. Purple copper

Purple copper, also known as red copper, is the simple substance of copper, which is named because its color is purple-red. See copper for various properties. Red copper is industrial pure copper, with a melting point of 1083 ° C, no isomeric transformation, and a relative density of 8.9, which is five times that of magnesium. The mass of the same volume is about 15% heavier than ordinary steel.

It has a rose-red color and it’s surface turns purple after forming an oxide film, so it is also called purple copper. It is copper containing a certain amount of oxygen, so it is also called oxygen-containing copper.

Purple copper

3. Red copper

Red copper is pure copper, also known as purple copper, which is named because its color is purple-red. It is the simple substance of copper. Red copper is industrial pure copper, with a melting point of 1083 ℃, no allotropic transformation, and a relative density of 8.9, which is five times that of magnesium.
The mass of the same volume is about 15% heavier than ordinary steel. Because it has a rose-red color and is purple after forming an oxide film on the surface, it is generally called copper. It is copper containing a certain amount of oxygen, so it is also called oxygen-containing copper.

Red copper has good electrical and thermal conductivity, excellent plasticity, easy to hot and cold pressure processing, and is widely used in the manufacture of wires, cables, brushes, electric corrosion copper for sparks, and other products that require good conductivity.

Red copper

The difference between red copper and brass

Exterior color
Brass: light golden yellow, shiny.
Red copper: Rose red and shiny.
Red copper: The copper content reached 99.9%.
Brass: about 60% copper; about 40% zinc; some brands contain about 1% lead, there are impurities.
Brass: Higher.
Red copper: lower
The density of brass is 8.93g / cm³. It mostly used for the lining of mechanical bearing bushes and is wear-resistant. Brass castings are commonly used to make valves and pipe fittings.
Red copper. Pure copper, also known as red copper, has a density (7.83g / cm3), a melting point of 1083 degrees, and is non-magnetic.
Main performance:
A. Room temperature organization
Ordinary brass is a copper-zinc binary alloy, and its zinc content varies widely, so its room temperature structure is also very different.
B. Pressure processing performance
α single-phase brass (from H96 to H65) has good plasticity and can withstand cold and hot processing, but α single-phase brass is prone to medium temperature brittleness during hot processing such as forging, and its specific temperature range varies depending on the Zn content The change is generally between 200 ~ 700 ℃.
C. Mechanical properties
Due to the different zinc content in brass, the mechanical properties are also different. The curve of copper mechanical properties varies with the zinc content. For α brass, as the zinc content increases, both σb and δ increase continuously.

The main difference is that the main elements of the two are different. Tin bronze is a bronze with tin as the main alloying element, and aluminum bronze is a copper-based alloy with aluminum as the main alloying element.

4. Tin Bronze

The tin content is generally between 3 and 14%. It is mainly used to make elastic components and wear-resistant parts. The tin content of deformed tin bronze does not exceed 8%, and sometimes phosphorus, lead, and zinc, etc.

5. Aluminum-Bronze

The aluminum content generally does not exceed 11.5%, and sometimes appropriate amounts of iron, nickel, manganese, and other elements are added to further improve performance. Aluminum bronze can be strengthened by heat treatment, its strength is higher than tin bronze, and its high-temperature oxidation resistance is also better. The main purpose is to be used as a screw, nut, copper sleeve, sealing ring, etc.

The difference between tin bronze and aluminum bronze

Tin Bronze: The alloy has high mechanical properties, wear reduction and corrosion resistance, easy cutting, good brazing and welding performance, small shrinkage coefficient, and no magnetism.
Aluminum bronze: Aluminum bronze containing iron and manganese has high strength and wear resistance. After quenching and tempering, it can increase hardness. It has good high-temperature corrosion resistance and oxidation resistance in the atmosphere and fresh water. It has good corrosion resistance in seawater, acceptable machinability, not easy to be soldered, and good pressure processing under hot conditions.
Tin Bronze: It is a non-ferrous metal alloy with the smallest casting shrinkage. It is used to produce castings with complex shapes, clear contours, and low airtightness requirements. It is widely used in steam boilers and sea ship parts. The mechanical properties can be used as wear-resistant parts and elastic parts of high-precision working mother machines. Lead-bearing tin bronze is often used as wear-resistant parts and sliding bearings. Zinc-tin bronze can be used as high-tightness castings.

Aluminum bronze: It has high strength, hardness, and wear resistance. It is commonly used to manufacture gear blanks and other parts. Aluminum bronze has good corrosion resistance. Aluminum bronze will not produce sparks under impact and can be used to The non-sparking tool material has excellent thermal conductivity and stable stiffness. As a mold material, it does not produce sticky mold or scratch the workpiece when it is stretched and rolled stainless steel plate heat exchanger.


Special aluminum bronze-mainly refers to aluminum bronze with an aluminum content of more than 11.5% and less than 15%. The element composition except aluminum is not much different from that of ordinary aluminum bronze. Because of the difference in aluminum content, special aluminum bronze Has higher strength than alloy steel and close to the hardness of alloy steel. It is widely used in force structural parts, transmission parts, etc. Because of its good corrosion resistance, compression resistance, and wear resistance, it is also used in the transmission shaft gear of high-speed trains.

6. Beryllium Bronze

Beryllium as a main alloy component is a kind of Wu xi bronze. The beryllium content of bronze is 0.2% ~ 2%, and then add a small amount (0.2% ~ 2.0%) of the third component of cobalt or nickel. The alloy can be strengthened by heat treatment. It is an ideal high-conductivity, high-strength elastic material. Nickel, chromium, titanium, and other elements, after quenching and aging treatment, the strength limit can reach 1250 ~ 1500 MPa, close to the level of medium strength steel. It has good plasticity in the quenched state and can be processed into various semi-finished products. And easy to cast and pressure forming.

The typical uses of beryllium bronze castings are used as plastic or glass casting molds, resistance welding electrodes, explosion-proof tools for petroleum development, and submarine cable shields. Beryllium bronze has high hardness, elastic limit, fatigue limit, and wear resistance, and also has good corrosion resistance, thermal conductivity, and electrical conductivity. It does not generate sparks when impacted, and is widely used as an important elastic element and wear-resistant parts And explosion-proof tools. Commonly used brands are QBe2, QBe2.5, QBe1.7, QBe1.9, and so on.

7. Sintered bronze

Sintered bronze with silicon as the main alloy element. In addition to silicon, sintered bronze used in industry also contains small amounts of manganese, nickel, zinc, or other elements. Silicon has a limited solid solution in copper. The maximum solubility can reach 5.3% at 852 ° C, and decreases with decreasing temperature. However, the age-hardening effect is not strong, and generally no strengthening heat treatment is performed.

Sintered bronze bond diamond wheel

Sintered bronze bond diamond wheel

QSi3-1-1 sintered bronze can be processed under pressure in cold and hot state. It has good mechanical, corrosion resistance, wear-resistance and welding performance. It is non-magnetic and does not generate sparks when impacted. It is widely used in machinery, chemical, petroleum, marine, and other industrial sectors application. The sintered bronze QSil-3 with 1% silicon and 3% nickel commonly used in industry has good plasticity after quenching at 900-950 ° C. After aging at 350-550 ° C for 1-4h, the strength can be more than doubled. This alloy has high wear resistance and high-temperature strength. Its electrical conductivity is also higher than that of general high-strength copper alloys. Therefore, manufacturing important parts in the machinery industry and other departments can also be used as high-strength overhead lines and conductive electrodes for communication.
QSi3.5-3-1.5 sintered bronze QSi3.5-3-1.5 is sintered bronze containing zinc, manganese, iron, and other elements, the performance is the same as QSi3-1, but the heat resistance is better, and the bars and wires are cracked by themselves when stored Is less inclined. QSi3.5-3-1.5 is mainly used as a bushing material that operates at high temperatures.

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