How to Extend the Service Life of Molybdenum Wires

Molybdenum wires are pressed and sintered from our high purity molybdenum powders to compact ingots by powder metallurgy and then drawing. As a leading molybdenum manufacturer, we are capable of providing wires with a range of diameter from 20 microns to 2mm. 

Many end-users would require a good quality of products. How to extend the service life of these wires? Here are some tips: 

1.Installation 

Wires made of molybdenum are easily deformed and broken. Therefore, they can not be bended during installation. If bended, cut it off to avoid wire breakage during operation. The cutting fluid should also be replaced in time during use because it will turn black after a long time of use, which will directly affect the performance of products.

2.Operation 

When the wire is discharged during operation, it will also be damaged. However, due to the good mechanical properties of molybdenum, the damage is small. Therefore, it would be better to using low-energy processing parameters to reduce the damage. After running for a period of time when the color of wire becomes write, workpieces can be cut with normal high current. In addition, after replacing the wire, running new wire for 5-10 minutes before cutting the workpiece, so that the internal stress of the molybdenum wires can be released. 

When the moly wire breaks during the operation of the cutting machine, most of the broken ends are within a dozen to dozens of turns after the reversing of the wire barrel. It can be seen that the metal wire at both ends of the head and tail is easier to be broken. Therefore, in the cutting process, the wire barrel is reversed to form a switch control block and move a little outward or inward at regular intervals.

3. Maintenance

Routine maintenance of molybdenum wire can also improve the service life, such as: daily storage, placement and time. It should be stored in a ventilated and cool place with low humidity, and the temperature is 20℃~25℃ to avoid oxidation. In addition, it should not be placed for more than 6 months. While using it, check whether the packaging is damaged or deformed.

If you have any inquiry of molybdenum wires, please feel free to contact us:

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Types of Silicon Carbide Heating Elements for Producing Lithium Ion Battery Components

Silicon carbide (SiC) heating elements are non-metal high temperature heating element made from high-quality green silicon carbide. Compared with metal electric heating elements, this element has the advantages of high temperature, oxidation resistance, corrosion resistance, long life, and convenient installation and maintenance. 

The operating temperature of the silicon carbide heating elements can go up to 1550°C in an oxidizing atmosphere, or inert gas atmospheres of argon or helium. in a reducing atmosphere, the maximum obtainable operating temperature is 1350°C. Nowadays, they are widely used in various high-temperature electric furnaces and electric heating equipment in magnetic materials, powder metallurgy, lithium ion battery components, ceramics, glass, metallurgy and machinery industries.

Our silicon carbide electric heating elements adopt a new production process for the availability of an excellent heat and cold resistance ratio, energy saving and long life. Meanwhile, they can avoid the damage to the furnace body caused by the excessive temperature of the cold zone. Chinatungsten Online manufactures the following types of SiC heaters. 

1.Equal-diameter Silicon Carbide Rod

It has the advantages of low resistance, long service life, and energy saving, which is commonly used in rare earth phosphors, electronics, magnetic materials, powder metallurgy, precision casting and other industries, as heating elements for pusher furnaces, mesh belt furnaces, trolley furnaces, and box furnaces.

2. Thick-end SiC Rod

It is an electric heating element composed of a hollow tubular heating part and a thickened end. Meanwhile, it is hard and brittle, resistant to rapid cold and heat, and will not deform under high temperature. Mostly used in test furnaces. 

3. U-Shaped Alpha Silicon Carbide Rods

The rod is composed of two equal diameter silicon carbide rods sharing a cold end, and can be connected to the power cord at one end of the kiln. Its surface can be used in the temperature of about 1500 ℃. Given that, it is mostly applied in kilns with high furnace temperature and high furnace temperature uniformity requirements.

4. Gun-shaped SiC Rod

This shape of element is improved from the U-shaped rod by extending 40mm to 60mm length at the U-shaped end to support the rod body. It is matched with double heating element rod to be used in the glass bottle industry to produce soda-lime flat glass. 

5. W-shaped Silicon Carbide Rod

The special rod is composed of a common silicon carbide rod connected to one end of three high-purity silicon carbide rods. The joint is also made of the same material, and the structure of the rod is exactly the same so that it can be used for horizontal installation in a float glass cell. Besides that, it can be directly connected to the three-phase power supply and the furnace top can be connected in one direction.

6. H-shaped Silicon Carbide Heating Elements

This heating element is commonly used for heating and heat preservation of forehearths and pot sections in the glass industry. As a non-linear resistor, its resistor has a large dispersion at room temperature.

7. Reaction Bonded Single Spiraled Heating Elements

Single spiraled element is an electronic component specially processed by precise calculation and design on the basis of equal diameter SiC rod. Its using temperature can reach 1500 ℃, used for heating of kilns with special needs. Its characteristics are: more power saving, simple operation, high temperature and long life.

8. Reaction Bonded Double Spiraled Heating Elements

The double spiraled element is an electronic component specially processed by precise calculation and design on the basis of the U-shaped heater. It is designed to meet the small space in the furnace and the normal U-shaped rod cannot be installed in the electric furnace. It is mainly used for the heating of kilns with special needs. Its characteristics are: power saving, simple operation, high temperature and long life. 

If you have any inquiry of silicon carbide heating elements, please feel free to contact us:

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Why Should We Do a Protective Coating for Molybdenum-copper Alloy (MoCu alloy)?

Molybdenum-copper alloy (MoCu alloy) is a pseudo-alloy composed of two insoluble metals molybdenum and copper. As a result, it gains characteristics both of these two metals, such as high thermal conductivity, low thermal expansion coefficient, non-magnetic, low gas content, good machining performance and special high temperature performance.

What is the protective coating?

In order to improve the high temperature resistance and welding performance of finished products, there can be a layer of coating on the surface, usually nickel or gold. Displacement plating, chemical roughening, chemical nickel plating, or cyanide gold plating are the most common used methods. 

We use scanning electron microscope and EDS to analyze its morphology and composition of the coating, and test welding and high temperature resistance by gold-tin welding according to GJB1941-94. The results show that the displacement plating method achieves the uniformity of the chemical properties of element Mo and element Cu at the interface of the Mo-Cu alloy substrate, and avoids the problem of excessive internal stress in the deposited crystal due to different chemical activities; chemical roughening increases the specific surface area at the interface of the substrate, increases the number of "mechanical bites" at the interface of the coating and the substrate, and improves the bonding strength of the coating and the substrate.

The high temperature resistance of the gold plating layer obtained on the surface of the MoCu substrate is ≥350℃, and the void ratio after welding is ≤30%, which meets the requirements of welding technical indicators. 

Molybdenum-copper alloy has high thermal conductivity, up to about 200W/m·K, and has the advantages of small thermal expansion coefficient and easy machining. It is used in spacecraft phased array antenna T/R module bottom plate and high-power microwave shell and power device carriers and other fields that have good application prospects. However, its surface wettability is poor and cannot meet the soldering functional requirements of solders such as PbSnAg, SnAgCu and AuSn.

In order to improve the weldability, it is necessary to coat a gold plating layer with excellent welding performance on the surface. however, as the surface composition of the molybdenum-copper alloy is composed of two metal elements with relatively different chemical properties, and the content of chemically inert Mo element is as high as 85%, it is difficult to coat the gold coating on the surface.

In aerospace products, the solders used in the early days were mainly low melting point solders such as PbSnAg and InSn. The peak temperature during the soldering process was all below 230°C, so the high temperature resistance of the gold coating is relatively low. With the development of T/R module housing and chip packaging technologies, high melting point solders represented by AnSn have been widely used. The peak soldering temperature is as high as 300℃. 

During the high-temperature soldering process, the gold plating layer and the molybdenum copper alloy substrate will expand due to thermal expansion. The thermal stress caused by the coefficient mismatch increases, resulting in quality problems such as skinning and blistering of the gold coating. Therefore, in order to meet the welding requirements of spacecraft stand-alone load products, higher requirements are put forward for the preparation and high temperature resistance of the gold coating on the surface of the MoCu alloy.

There are many grades for moly copper alloy, such as Mo85Cu15, Mo80Cu20, Mo70Cu30, Mo60Cu40, Mo50Cu50, Mo40Cu60. Different grades match different densities, thermal conductivities and coefficients of thermal expansion. Other customized grades also can be customized.

Chinatungsten is a professional manufacturer of molybdenum for more than two decades, if you have got any purchasing plan for related products, please feel free to contact us, we will offer you our most favorable prices and qualitied products. 

If you have any inquiry of MoCu plates, please feel free to contact us:

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How to Avoid TZM Rods from Splitting During Processing Nuzzle Tips for Hot Runner System?

Pure molybdenum has very high melting point, which makes it useable in most high temperature applications. However, with the development of molybdenum alloy, titanium-zirconium-molybdenum (TZM) alloy has become a good all-round candidate no matter in vacuum furnace industry, medical diagnostic equipment industry or other industries. 

Although TZM alloy products are expensive than pure molybdenum, in certain applications the additional cost is offset by its increased strength at elevated temperatures. 

People add trace elements such as titanium and zirconium to molybdenum to remove the grain boundary embrittlement phase through solid solution strengthening of trace elements, and its reactant acts as a dispersed phase to strengthen the alloy to improve its performance. 

The suggested applied temperature is between 700 and 1400 degrees Celsius. Like pure molybdenum, it starts to oxide at 400 degrees Celsius, and rapidly oxides at above 500 degrees Celsius. However, at operating temperatures exceeding the recrystallization temperature of pure molybdenum (900 to 1,100 degrees Celsius), TZM is much stronger. And in load-bearing applications exceeding 1300 degrees Celsius, TZM is twice as strong as pure molybdenum.

In the vacuum furnace industry, TZM is the material of choice for load-bearing hearths and horizontal posts; in the medical diagnostic equipment industry, it is used as the material of choice in rotating anodes in X-ray tubes; in hot runner system, it can be machined into nuzzle tips and keep plastic in melt status. 

However, when applied in hot runner systems, TZM rods will be machined into nuzzle tips, and during this process, some problems may occur, such as split, cracking, unmachinable, tools easy to be damaged, or debris easy to stick on tools. 

Reasons for these problems are complex, for example, when tools are easy to be damaged during processing, it probably shows signs that TZM rods has high hardness. However, it cannot be assured it is the problem of hardness, the selected tools may also cause this problem. If you require lower hardness, debris are easy to stick on the surface of tool. Therefore, there should be a comprehensive solution for these problems. 

Chinatungsten is a professional manufacturer of molybdenum. Our knowledgeable and experienced refractory metal sales engineers are standing by to help you select the best metal for your application and solve whatever problems you meet. 

If you have any inquiry of TZM rods, please feel free to contact us:
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How to Select Tin Oxide Electrodes or Molybdenum Electrodes Based on the Glass to Be Produced

There are many kinds of glass melts with different melting temperature and raw material components, which have different requirements for the electrode during melting. Therefore, special materials of electrode will be customized for this process. 

The melting point of most glass lies around 1,400~1600℃, depending on its composition. As a result, glass production requires a great deal of heat energy. Regenerative glass furnaces, recuperative glass furnaces, oxygen-fuelled glass furnaces as well as all-electric glass furnaces are the most popular furnaces. Usually, electrodes made of molybdenum metal and tin oxide are enough for these furnaces. 

Tin oxide electrodes can be used to melt almost all different glass at temperatures below 1450°C. Due to the demand for special glass production, they can also be used in glass melting furnaces above 1650°C. While molybdenum electrodes are commonly used for melting soda-lime glass and high borosilicate glass, with a higher applying temperature and surface current intensity. Their operating temperatures can be as high as 2000 ℃.

Molybdenum electrode is made of pure molybdenum material. Its surface temperature is generally higher than the temperature of the molten glass by 200°C in the glass furnace. If the surface temperature reaches 2000℃, the loss of the electrode is also greater. Generally speaking, surface temperature is related to the current density. The greater the surface current density, the faster the loss. The most suitable surface current density should be 1.0～0.7A/cm2. When the furnace requires higher glass quality and longer serving life, lower surface current density should be required. The maximum surface current density of the electrode should not be greater than 2A/cm2. Usually, the consumption of electrode is relatively small in glass or E glass with higher iron content.

Tin oxide is a high-quality refractory material and is non-conductive. Various conductive additives are added to the tin oxide powder to become a tin oxide electrode after sintering, which has good conductivity after the temperature is higher than 1000 ℃. Tin oxide electrodes are generally recommended to be used in glass furnaces at a temperature not higher than 1450 ℃. When the rare earth glass is melted higher than 1650℃, it can still maintain very good performance, but the service life will be shortened accordingly.

The correct use of molybdenum electrode and tin oxide electrode is critical to furnace design and manufacturing engineers. The value of the electrode is often only 10% to 15% of the value of the furnace, but for glass furnaces of different glasses and designs, the correct application of the electrode is the decisive factor for the success of the furnace.

If you have any inquiry of molybdenum electrodes, please feel free to contact us:
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Molybdenum Bar Is Used in Steel Industry to Improve Corrosion Resistance of Stainless Steel

Whether you are preparing meals by a campfire in the wilderness or repairing a malfunctioning toaster in an apartment in the city, multifunctional Swiss Army Knife can meet all your requirements. With adding the material of molybdenum, the product is durable, and can be as sharp as ever. 

Molybdenum is an important part of tool manufacturing. The EN 1.4110 martensitic stainless steel used in the blade contains 0.5%-0.8% molybdenum, which makes the material wear-resistant and corrosion-resistant, and the knife can remain sharp. 

Molybdenum metal has the largest consumption in the steel industry, mainly used to produce alloy steel, stainless steel, tool steel and high-spread steel, cast iron and roller. As an alloying element of steel, it can improve the strength and toughness of steel, the corrosion resistance of steel in acid-base solutions and liquid metals and the wear resistance, hardenability, weldability and resistance of steel. For example, stainless steel with a molybdenum content of 4%-5% is often used in places with serious erosion and corrosion such as marine equipment and chemical equipment.

Most of this material is directly used for steelmaking or cast iron after industrial molybdenum oxide briquetting (that is molybdenum bar), and a small part is first smelted into ferro molybdenum and then used for steelmaking. Usually, moly bar is in a shape of block or bar, with large tolerance for the size. Its purity is about 99.5% minimum and surface will not be polished or grounded, showing its real status of this metal. 

Molybdenum bar is made of molybdenum powder. After sintering and forging, it is formed. Unlike other molybdenum finished parts, its package is metal bucket, which is safe but simpler. 

Chinatungsten Online, as professional manufacturer for more than two decades, can offer related products to steel industry, medical industry, spaceflight, aviation or other industries. If you have an interest in our products, please feel free to contact us. 

If you have any inquiry of molybdenum bar , please feel free to contact us:

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Why Use Molybdenum Electrode to Melt Glass?

Glass is prized because of its clarity, beauty and numerous versatilities. The presence of molybdenum is helpful for its manufacturer and related products for daily use as the material has high strength at high temperature and also has corrosion resistance to molten glass. 

There are records in history for the use of glass by humanity, which can be traced back to the era when primitive people used obsidian glass naturally formed by lava as a knife and cutting. In the development process from ancient history to modern times, glass has proved its practicality in countless applications and has become an indispensable part of daily life. Nowadays, molybdenum is also indispensable for glass manufacturing.

With the advent of electricity, engineers began to design electric furnaces to replace coal or gas fuel furnaces traditionally used to melt glass. Early designs tried to relied on electric arc and radiation to heat glass, but these techniques were not widely accepted. In the 1950s, researchers discovered that molten glass can conduct electricity, and the molybdenum metal electrode can directly heat the glass by passing an electric current through the molten glass.

After that, the use of molybdenum was increased. Molybdenum electrode can be side-entry or bottom-entry. There are also molybdenum stirrers to help to make the melt uniform. The molten glass can protect the molybdenum components from the rapid oxidation of air at high temperatures, so that they have a long and reliable service life. The designer uses inert cooling gas or water cooling to protect the electrode part outside the glass from being oxidized.

The molybdenum component can also protect the refractory materials of the furnace from wear and corrosion, as a refractory brick that covers vulnerable areas as ‘armor’. Even in the absence of molten glass protection, advanced coatings make these components resistant to oxidation during cold start.

If you have any inquiry of molybdenum electrode , please feel free to contact us:
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Tel.: +86 592 5129696/+86 592 5129595

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