Copper tungsten rods represent a remarkable amalgamation of two vital elements – copper and tungsten. Due to its outstanding properties, copper tungsten rods are used in many applications from EDM erosion to resistance welding.
In this article, we will explore more deeply about this material and get to know its compositions, manufacturing process, applications, and more related topics.
Introduction
Copper tungsten rods, a type of composite material, are renowned for their exceptional conductivity and high strength. Tungsten has high hardness, high melting points, and abrasiveness. Copper has good electricity conductivity and excellent thermal conductivity. With the combination of different ratios of copper and tungsten, copper tungsten rods have gained both properties of these two elements. Copper tungsten rods are dense hard metals with low thermal expansion, good thermal and electrical conductivity, excellent arc resistance, superior wear resistance, and strength at elevated temperatures.
The Composition of Copper Tungsten Rods
Copper tungsten rods typically consist of a varying ratio of copper and tungsten, ranging from 10% to 50% tungsten, with the remaining percentage being copper. Normal used grades are W70Cu30, W75Cu25, W80Cu20. With a higher content of tungsten, the metal has higher density, higher hardness, and lower thermal conductivity and thermal expansion rate. To maximize the properties of each application, the optimal ratio of tungsten and copper is the key point.
The Manufacturing Process of Copper Tungsten Rods
The production of copper tungsten rods involves a sophisticated manufacturing process that begins with the precise blending of copper and tungsten powders. After that, add a certain mass proportion of nickel powder to the tungsten copper powder and mix evenly; the mixed powder is cold isostatically pressed to obtain a blank; Pre-sinter the blank at high temperature to obtain a sintered compact of tungsten skeleton; Infiltrate copper into the sintered billet of the tungsten skeleton to obtain a copper-infiltrated billet; To get different surface of the rods, use different methods like machining or grinding.
Properties and Characteristics of Copper Tungsten Rods
Because tungsten copper has the advantages of both tungsten and copper, tungsten copper has excellent comprehensive properties such as good electrical and thermal conductivity, low expansion coefficient, high-temperature strength, and good wear resistance. Without nickel adding, tungsten copper is non-magnetic. The hardness is different with different combinations of tungsten and copper which varies from 115HB to 260HB. Tungsten is brittle, but by adding softer copper, the material becomes better to machine without bursting and has not much burr as copper machining.
Applications in Various Industries
Tungsten copper rod has various excellent properties and is widely used mainly in the following aspects.
Electrical contact material
Tungsten copper rod has high-temperature resistance and electrical ablation resistance. In the 1960s, some more advanced countries used tungsten-copper rods to manufacture components such as electromagnetic fuses and throat linings on rocket missiles. In addition, in the field of electrical contacts, the performance of contact materials determines the development trend of high-voltage switches. Tungsten-copper rod materials have high electrical conductivity, resistance to electrical ablation, and good braking performance, and are widely used as contact materials for high-voltage and ultra-high-voltage switching appliances.
Heat sink material
As a heat sink material, the material has high requirements on the uniformity of the structure, air leakage rate, thermal conductivity, thermal expansion coefficient, etc. Therefore, according to actual needs, tungsten-copper alloy materials can use the adjustment of tungsten and copper elements to change the thermal expansion coefficient. and thermal conductivity, which can effectively avoid fatigue damage caused by thermal stress and affect the performance of tungsten copper alloy materials.
EDM electrodes material
Electrode material is a key material in EDM and is directly related to stability, accuracy, joint surface roughness, etc. Since general electrode materials have relatively poor ablative properties and a short life consume a lot of money. The processing accuracy is also relatively poor and even requires multiple processing. For this reason, with the development of tungsten-copper alloy materials, to solve the shortcomings of electric discharge machining, tungsten copper can be used to make electrical machining electrode materials. This can not only effectively improve the accuracy and reliability of processing, but also reduce electrode consumption.
Advantages and Disadvantages of Copper Tungsten Rods
First, tungsten copper rods have high hardness and strength and can withstand high-intensity impact and pressure. Therefore, they can be used in the manufacture of radiation shielding parts and some military weapons. Secondly, tungsten copper rods have very good thermal and electrical conductivity and can be used to manufacture heat spreaders, pads, or substrates in micro semiconductor field. In addition, tungsten copper rods also have good corrosion resistance and wear resistance, so they can be used to manufacture high-quality tungsten copper EDM electrodes and resistance welding electrodes, etc.
However, their high density and relatively high cost might pose certain limitations in specific applications.
Comparing Copper Tungsten Rods with Other Materials
In EDM applications, there are types of electrode materials like pure copper, brass, graphite, and copper tungsten. Here we compare copper tungsten with other materials.
Pure copper electrode performs stability in mold processing with high productivity, but it erodes quickly and is more expensive than other electrode materials. Because of its great toughness, poor machining performance, and difficult grinding, its machining accuracy is low. The pure copper electrode is suitable for machining small cavities and high-precision mold cavities.
As electrode material, brass has good stability, high productivity, lower price compared with the pure copper electrode, and good machinability, but its grinding performance is not as good as steel and cast iron. The loss of brass electrodes is very large. As a result, brass electrodes are commonly used in perforating small holes with low surface roughness, high requirements for dimension and shape accuracy, and complex shapes.
The graphite electrode has a small eroding loss and good processing stability. It is easy to machine the mold and has higher productivity. The price is approximately the same as copper, but its mechanical strength is poor. Graphite is a common electrode material for EDM cavity processing, which is suitable for large, medium, and small cavities. Because the coefficient of thermal expansion of graphite is small, it is suitable for perforating large electrodes.
Copper tungsten has good machining stability, low electrode loss, and perfect electrical machining performance. Its grinding performance is better than copper. The drawback is that it is very expensive. It is mainly used for piercing high-precision deep holes, straight wall holes, small areas, high-precision mold cavities, and hard alloy mold.
Factors Influencing the Cost of Copper Tungsten Rods
Several factors influence the cost of copper tungsten rods, including the current market prices of copper and tungsten, manufacturing complexities, and the specific requirements of the end-use applications.
Tungsten is an expensive metal. The increase or decrease of the powder has important influences on the final price of copper tungsten rods. So normally if you buy from the supplier, they will always give a quotation validity of 5 days or 7 days.
The final applications also affect the cost of production. Different application has various requirement that will influence the grain size, the process flow, and the testing. For example, if you buy the rods to be used for heat sinks, the coefficient of thermal expansion and thermal conductivity will be paid attention to. This application will have a higher cost.
Maintenance and Care Tips for Copper Tungsten Rods
Copper tungsten rods are very easy to oxide. It is very important to touch the metal with gloves. If not wearing gloves, the rods will oxide have marks and become hard to remove.
To avoid oxidation, we normally pack the rods with kraft or oiled paper. If the material you received already has oxidation, you can use fine sandpaper to polish it softly. When you do not need to use the material for a while, we suggest you put it on a shelve with desiccants in a sealed box to prevent it contacting with air to the utmost.
Copper tungsten is easy to have a bruise that is because the alloy is with copper. As we all know, copper is soft. If there are not enough protective materials, rods are easy to bump into each other or bump into the box wall. After clashing, the surface will have a dent or hole or aversion and it is hard to fix.
Conclusion
In conclusion, copper tungsten rods play an important role in industrial applications because of their special properties. If you want to know more about copper tungsten, pls let us know.
Best Material Co., Ltd is a premier supplier of copper tungsten rods with various dimensions and compositions. Our rods are delivered with quality control to ensure high accuracy dimension control, concentricity, roundness, nice surface roughness, and no pores.
