Aluminum Foundry Fluxes have been widely used in aluminum and aluminum alloy casting production. Although flux products have continued to grow, the main components and formulations have basically not changed significantly.

The purpose of using aluminum casting flux can be divided into the following two: reduce the aluminum content wrapped in alumina slag; remove the slag in the aluminum liquid and improve the cleanliness of the aluminum liquid.

As product quality requirements become higher and higher, the types of melting furnaces and holding furnaces have also changed and become more suitable for specific alloys. Similarly, solvents are increasingly targeted to specific alloys and furnace types. In addition to the flux that reduces the aluminum content in the slag (usually called the "slag breaker"), there is also a need to prevent the moisture in the atmosphere from reacting with the molten aluminum to absorb hydrogen. In addition, in some alloys, it is necessary to prevent magnesium from burning out, and in alloys modified by sodium or strontium, it is necessary to avoid reducing the effect of deterioration.

For the above reasons, we have developed the following types of Aluminum Foundry Fluxes: refining agent, deslagging flux, degassing agent, covering agent, furnace wall cleaner, modifier, sodium-free flux, and granular flux. These fluxes can be suitable for stationary crucible furnaces, reverberatory furnaces, gas furnaces, electric furnaces, and oil furnaces.

With the continuous growth of the demand and price of aluminum alloy, the amount of flux will increase accordingly. However, the amount of flux added per unit alloy has been controlled, which is significantly lower than the previously recommended level. One of the reasons is environmental protection considerations. Studies have found that fluoride has the greatest impact on the environment. If fluoride is completely removed from the formulation, the efficacy of the flux is very low. At the same time, it was found that not all the flux sprinkled on the surface of the melt can function.

Continuous casting is a casting method used in high volume production of metals with a constant cross-section.

The method uses an open ended graphite die which is surrounded by a copper jacket.

Through which is poured molten metal. The graphite mold is typically water cooled.

This allows the molten metal to solidify within the die, the custom solid metal form is then extracted from the mold and pulled/passed through rollers and water sprays.

This process removes the heat from the metal, and gradually solidifies it.

Graphite Ring is a widely used in continuous casting.

The die molds are generally produced out of graphite.

In these types of applications, the types of graphite used are ISO-Molded types.

Small porosities and good machinability are required properties, and ISO-molded graphite has those.

In rare instances, where large ingots are produced, extruded graphite is used.

There are two types of continuous casting processes, a vertical casting and a horizontal casting. Graphite molds are used in both types of applications.



A wide variety of alloys are fabricated using continuous casting in graphite molds.

Gray cast irons, copper-nickel alloys, nickel silvers, aluminum bronzes or gold and silver alloys, are just some of the alloys being produced with graphite molds.

The coefficient of thermal expansion is an important factor that determines why graphite is used as mold material.

The casting mold is a medium with very un-uniform temperatures, from hot inside due to the molten material, to cold on the outside due to the cooling process applied to it.

The low coefficient of thermal expansion that graphite exhibits, allows the mold to function without deforming or cracking.

Another very important factor is self-lubrication..

Graphite is a solid lubricant that allows for low friction between the mold and the cast material.

Subsequently graphite allows for smooth extraction of the casting.

There are various factors determining the lifetime of the mold.

From the composition of the casted materials, to the casting temperature, to the cooling rates, all affect the life of the graphite mold.

In general, graphite molds can operate continuously in excess of 100 hours. Also, graphite molds can be re-machined to smooth surfaces and used again.

The specific graphite grade used is also determined by a multitude of factors.

The main factor is the composition of the alloy to be casted. For example, for a gray iron, or a high nickel alloy a graphite resistant to wear is required, while for brass a relative dense graphite with enough open porosity to allow zinc to evaporate, will be a better choice.

Designing graphite molds for continuous casting requires taking in consideration all these factors and applying them to your specific application.

Grade selection is of the most importance, and should include input from foundry men, graphite manufacturers, and machine shops specialized in machining graphite.

Even then, when designing a new system, actual trials could be needed, before an actual graphite grade is selected.

Attached is a video showing the precious metal strip casting process using an IRM caster fitted with Semco Carbon graphite components.

Molten aluminum is extremely reactive, so when it comes in contact with moist air or wet tools, the water decomposes to release hydrogen in the melt. Excessive quantities of this dissolved gas have a well-documented detrimental effect on the mechanical properties of the final aluminum castings. What is also well known to anyone making castings is that dissolved gas has an overriding effect on the distribution and amount of porosity and shrinkage. Dissolved hydrogen levels must be controlled to minimize scrap. To control gas in aluminum, metalcasters must accomplish two things:

1. Prevent and minimize introduction of hydrogen in the melt.
2. Measure and remove the hydrogen prior to pouring.
This article will focus on measurement and removal.
Gas Removal

The ability to degas molten aluminum is generally accomplished by using a purge gas, typically introduced into the melt by a rotary degassing unit. This degassing process is limited by thermodynamic laws; when purge gas bubbles are introduced to the melt, they collect hydrogen as they float toward the surface. The best possible situation is these hydrogen-saturated bubbles leave the melt and reduce hydrogen levels. In this case, the process efficiency is 100% from the thermodynamic point of view. But as the gas content in the melt drops, so does the equilibrium pressure of hydrogen in the bubbles, so the amount of purge gas required to remove the remaining hydrogen must increase.

The equilibrium gas removal ratio is shown in Fig. 1 for pure aluminum above 1,400F (760C). A gas removal ratio of 200, for example, means it will take 200 liters of inert gas to remove one liter of hydrogen. This behavior limits a metalcaster’s ability to degas to a very low level of hydrogen. The solubility also increases exponentially with temperature, meaning an increase of 200F (111C) doubles the solubility. All things being equal, a higher temperature of an aluminum melt will increase the necessary degassing time.

Alloying elements also can have an effect on hydrogen solubility. The effect of alloying elements is characterized by changes in the alloy correction factor, with some common casting alloys show in Table 1. Alloys having greater values are more difficult to degas, so, for example, aluminum 535 will take four times longer to degas than pure aluminum. Fortunately, these factors can be controlled and the gas content and process required to eliminate excessive porosity in aluminum castings can be achieved without undue difficulty in most cases.

Practical Degassing Procedures
Degassing is usually accomplished in one of three areas of the metalcasting facility:

1. In the transfer ladle, used to convey metal between melting and holding furnaces.
2. In crucible furnaces, usually just before the molten aluminum is cast.
3. In an in-line system, when the metal is conveyed to holding furnaces through a launder.

The first two options are most common and the degassing operation for both is typically accomplished using a rotary impeller degasser (RID). In practical terms, all rotary degassers are not created equal. It is important to have an optimum head design to produce highly efficient, small bubbles. Significant cost savings may be realized from shorter treatment times and reduced gas usage. In the past, the metalcasting industry has gravitated toward simple head designs, which are less costly to machine but produce larger bubbles. This path presents a false economy due to reduced efficiency.

Adjusting Process Parameters
Once the RID unit is fully lowered into the liquid metal with the shaft in place, the degassing operation can begin. The best shaft location is slightly off the centerline of the crucible or ladle to help avoid vortex formation with its circular rotation in the liquid metal. An offset distance of 2-4 in. from the centerline is usually sufficient. The use of a baffle plate also is a good idea, because the baffle opposes the circulation movement of metal and reduces vortex formation.

With the RID in the proper location, the unit should be turned on and the shaft speed should be set to 300 RPM. The inert gas flow also should be on and operators should then adjust the gas flow rate and shaft speed. Gas flow should be increased until see gas bubbles are visible as they float to the surface of the liquid metal. As the gas flow increases, the size of the bubbles should increase.

The desired result is a good dispersion of small bubbles while maintaining a relatively quiet surface. When an optimal combination of flow rate and shaft rotation speed is found, note the parameters for future use. Also note the total degassing time, which normally falls somewhere between four and eight minutes, unless the temperatures are very high or the amount of gas needed is low.

Gas Measurement
There are two primary methods of gas analysis, sampling techniques and in situ methods. Sampling techniques may be further divided into two classes. In the first, a liquid sample is withdrawn and introduced directly into the measuring instrument before solidification takes place. In the second, a sample of liquid is poured into a specially designed mold and the solid sample is analyzed. The methods of analysis are shown in Table 2.

All three methods of analyzing a liquid sample somewhat depend on the inclusion content of the melt, because these inclusions nucleate gas bubbles. Fig. 2 shows a pore in an A356 casting that has nucleated on oxide films. In spite of this problem, the Reduced Pressure Test (RPT), a procedure of examining a solid sample, is a commonly used and effective tool. The procedure is easily understood and followed. The equipment is simple, rugged and inexpensive and the results usually correlate to casting quality. However, pressure must be controlled during solidification.

Either the solidified RPT test sample is cut and polished to yield a qualitative or semi-quantitative measure of gas content or the sample density is determined by measuring the sample weight when it’s dry and then suspended in water. As long as there is no shrinkage in the sample, measuring the density is the preferred method as it eliminates the subjectivity associated with visual examination of the cut surface.

With in situ techniques, the sampling process causes no errors, so these measurements have the potential to be the most accurate and reliable. The majority of in situ methods feature a system that involves recirculating inert gas introduced into the melt by a sample probe. The inert gas is recirculated through the melt, collected and passed over a differential thermal conductivity sensor to determine the hydrogen content of the gas. This recirculation continues until the hydrogen content reaches a value in equilibrium with the melt.

The new method for measuring hydrogen is promising. The latest version of the electrochemical sensor is nearly equivalent to a thermocouple. This would be the holy grail of gas measurement, allowing us to measure gas like we measure temperature with handheld devices.

Practical Considerations on RPT
At least 90% of aluminum metalcasters in North America use the RPT to determine metal quality. A few practical approaches can improve performance.

The necessary equipment for a vacuum evaluation of an aluminum melt consists of a pump, a gauge to monitor the vacuum level inside the test chamber and a control system to regulate the pressure (Fig. 3). In practice, the molten sample is placed on the pedestal, a chamber with a viewing port is placed over the sample, the chamber is evacuated to the desired pressure, and the sample is allowed to solidify under the reduced pressure. The reduce pressure in the chamber causes dissolved hydrogen to come out of the solution in the melt and either escape from the sample through the molten surface or form bubbles inside the solidifying sample.

It is important that the operator can view the sample during solidification to see if bubbles form on the surface. In practice, the reduced pressure test is conducted two ways:

1. Low Gas Contents: Sometimes low gas metal may be required, such as needed for high-end aerospace castings or safety critical components. In these cases, the best procedure is to use a low test pressure (high vacuum) and to count bubbles forming on the surface. When less than two or three bubbles appear on the surface of the casting, gas content is low.
2. Medium to High Gas Contents: Sometimes higher gas levels are beneficial, such as in permanent mold castings, where higher gas level can help avoid shrinkage. In this case, a higher test pressure (lower vacuum) is used so that the gas remains inside the solidifying sample. The test result is usually measured by determining the density or specific gravity of the RPT sample.

In either case, it’s a good idea to train operators to look at the surface of the samples, both during the test and afterward. Two RPT samples are shown in Fig. 3. The sample on the right is of better metal quality, having fewer oxides and presumably lower gas content.

It’s important to choose the correct test pressure for the RPT test. To do this, one needs to know a little more about how pressures are measured and how pressure determines when porosity is found during solidification. Most of the gauges used on RPT testers are differential, measuring the difference in pressure between the vacuum test chamber and ambient air. At sea level, the average atmospheric pressure will support a column of mercury 29.92 in. (760mm), or 30 in. for simplicity’s sake. Most metalcasters will use a gauge pressure of 26-28 in., which is called vacuum level or pressure.

A356 alloy can be chosen as an example to show what happens during solidification. The metal contains a hydrogen gas content of 0.12cc/100g, a fairly low gas content. When a sample of this metal is taken from the crucible and placed in a RPT, the pressure of hydrogen increases because of two factors:

1. The sample cools to a lower temperature.
2. As freezing progresses, hydrogen and silicon segregate and accumulate in the remaining liquid.

The gas pressure continues to grow during solidification until it reaches the equal of the average atmospheric pressure when 70% of the sample had solidified.

For a casting of this metal freezing on your shop floor, porosity cannot form until 70% of the material is frozen solid. However, when a vacuum is applied, the situation is different. First consider the case where a gauge pressure of 28 in. is applied to the solidifying sample. The gauge pressure of 28 in. corresponds to an absolute pressure of 50 Torr. This is slightly below the equilibrium gas pressure in this sample at the start of solidification, so gas bubbles may form on the surface of this sample before it starts to freeze.

Receiving accurate readings from reduced pressure tests is essential to creating quality castings. Here are a few of the many ways of ensuring proper RPT procedures:

Use a thin-walled cup for sample collection.
Skim oxides from the melt
surface.
Preheat the cup in an adjacent surface area.
Transport sample rapidly to a vacuum unit with proper seals and pump capacity.
Cover the chamber that allows visual observation.
Control vacuum to target level.
Adjust cycle time to allow for full solidification of the sample.
Measure specific gravity of the sample and compare to process specifications (or count bubbles on the surface).

In this second blog in our series on foundry equipment and machinery, we will be looking at the degassing unit.



As we’ve explored in an earlier blog, degassing is used to reduce the risk of gas porosity in aluminium sand casting. Porosity can occur when hydrogen is introduced into the metal during the melting stage. This can be drawn in through atmospheric humidity or moisture in the foundry.

In degassing, the molten metal is purged with nitrogen gas before the pouring stage. The nitrogen gas reacts with any hydrogen before dissipating from the molten metal.

Fast, effective degassing
At Haworth Castings, we use a hand-held rotary degasser – which has a rotating shaft and rotor at the base of a long narrow pole with handles. This unit is attached, through a tube, to a nitrogen canister.

The degassing unit is placed in the molten metal and, once operational, a high volume of bubbles is generated across a large surface area. This leads to the fast diffusion of hydrogen into the gas bubbles. The degassing time is dependent on the casting requirements.

Degassing fluxes (or tablets) containing chlorine or fluorine salts are used as an alternative method in some foundries. The flux tablets are plunged into the molten metal. These salts react with the hydrogen to form compounds, which can be removed from the melt.

However, the rotary degasser is significantly more effective in removing hydrogen from the molten metal.

Of course, the nitrogen gas used in degassing must be stored in a safe area and we follow stringent health and safety procedures in this respect. It is kept in a controlled and secure storage unit away from our foundry operations.

Adtech Industries offers Graphite ring which are manufactured using high-grade material imported from the most credible sources. We offer our customers a broad range of Carbon Graphite Rings, which are available in various sizes and specifications. Carbon Graphite Rings are available for mechanical seals. We offer Carbon Graphite Rings in various sizes and designs and with close dimensional tolerance for use as an integral part of mechanical seals.





BrandRGLThickness5 mm to 275 mmOD10 mm to 300 mmID5 mm to 275 mmColorBlackGradeGrade-I, Grade-II (Fine), Grade-III (Normal), Imported Grade

Molten Aluminum Filter Spain Aluminum is also called ceramic foam filter. The three-dimensional feature network has a uniform skeleton structure with pink or white protrusions.

Features of Molten Aluminum Filter
It can effectively remove large inclusions in molten aluminum and absorb micron-sized particles of inclusions. In aluminum, aluminum foil, and aluminum alloy profiles, it can improve surface quality, improve product performance, improve microstructure, and improve performance. It is widely used in the production field.

Molten Aluminum Filter Spain Aluminum is made of non-stick aluminum material, with the characteristics of non-stick aluminum, the product is white or milky white.

Molten Aluminum Filter Spain Aluminum is suitable for the production of high-quality and demanding aluminum and aluminum alloy purification processes through physical and chemical adsorption.
Ceramic Foam Filter Malaysia Aluminium can effectively remove various oxidized inclusions produced in the aluminum casting process, thereby reducing casting defects, improving casting quality, and providing high-quality materials for deeper processing.
Ceramic foam filters Malaysian aluminum must be preheated before use. The filter plate must be completely sealed in the aluminum water filter box to ensure that the aluminum water passes through the filter plate. The total amount of filtration should not exceed the prescribed limit. If the amount of slag in the aluminum water is too high, it must be adjusted by multiple filter components or by reducing performance.

Ceramic foam filter size
660x660x50 (26 inches)
584x584x50 (23 inches)
508x508x50 (20 inches)
432x432x50 (17 inches)
381x381x50 (15 inches)
305x305x50 (12 inches)
228x228x50 (9 inches)
178x178x50 (7 inches)

Pore ​​size of ceramic foam filter (PPI): 10/20/30/40/50/60

The 30ppi 40ppi cast filter is the most widely used ceramic foam filter in the aluminum casting industry.
Ordinary aluminum castings generally use 10-40ppi ceramic foam filters plates.
High-grade aluminum and aviation materials generally use 30-60ppi ceramic filter plates.

Ceramic foam filter Suppliers Inalum effectively removes large inclusions in molten aluminum, adsorbs micron-sized particles of fine inclusions, and plays a role in improving surface quality, improving product performance, improving microstructure, and increasing output.

Aluminum alloy casting process performance

It is generally understood as a combination of outstanding performance in the process of filling, crystallization and cooling. Fluidity, shrinkage, air tightness, casting stress, coiling.

These characteristics of aluminum alloy depend on the composition of the alloy, but also related to casting factors, alloy heating temperature, mold complexity, gate riser system, gate shape, etc.

Fluidity refers to the ability of the alloy fluid to fill the mold. The measurement of fluidity determines whether the alloy can cast complex castings. Eutectic alloys have better fluidity than aluminum alloys.

There are many factors that affect fluidity, especially the composition, temperature and solid particles of contaminants such as metal oxides and metal compounds in the alloy liquid. However, the fundamental external factors are pouring temperature and pouring pressure (commonly known as pouring). head). A sort of

In actual production, in addition to strengthening the smelting process (refining and slag removal), it is also necessary to improve the formability (sand mold permeability, metal release and temperature) without affecting the alloy. On the premise of ensuring the quality of casting, increase the casting temperature to ensure the fluidity of the alloy. A sort of

Ceramic foam Filter Suppliers Inalum purchase website www.adtechamm.com

The choice of agents must conform to the company’s development strategy.

AdTech is in a period of rapid development. He chose aggressive agents and agents who are actively developing business.

If the agent has been in the local business for more than 10 years, then we will give priority to you.

Indonesian agents should sell Ceramic foam filters like this

A. Before developing new markets, clarify your channel goals and regional goals, and plan which foundries will sell products.

B. Visit various channels of the target market and ask the OEM purchasing personnel.

Recently, Indonesia’s Bintan Alumina Alumina Phase 1 million tons project completed the alumina output of 86,500 tons in September 2021, achieving the target of reaching the standard and output, and the energy consumption and product quality have reached the international advanced level.

The alumina project in Bintan Nanshan Industrial Park in Indonesia is implemented by the company’s indirect overseas subsidiary BAI. The construction site of the project is located on Bintan Island, Riau Islands Province, Indonesia. The planned alumina production capacity of the project is 2 million tons per year, which will be constructed in two phases. After the completion of the project, the company will be able to use Indonesia’s rich local bauxite and coal resources to produce alumina, achieve lower-cost alumina production capacity expansion, enhance the company’s profitability, and improve the company’s ability to resist risks.

Molten Ceramic foam Filter Kamensk Aluminium is made on the basis of a carrier with a rigid network structure and combined pores of organic ceramic foam filter.
The production process is as follows: the carrier is placed in the thixotropic alumina slurry, the automatic extrusion process is adopted, and the center square is corrected to make the slurry evenly settle in the carrier foam skeleton.
After the carrier is dried and hardened, the final product is made by frying at a high temperature of 1180°C.
The filter is installed in the filter housing to filter out the impurities in the molten aluminum alloy, which helps to meet the requirements of high value-added, high-tech precision aluminum alloy castings.
For example, computer hard drives, PS bases for printing, canned materials, turbojet fan blades, etc.

Advantages of Molten Aluminum Filter Kamensk Aluminium
Ceramic Foam Filters adopt the principle of adsorption, which can effectively remove large inclusions in molten aluminum and effectively adsorb small inclusions.
No debris falls off, effectively reducing the pollution of molten aluminum.
Excellent thermal shock resistance, improve the corrosion resistance of molten metal.
Automatic flow production, 3 calibration procedures, accurate size, close to the filter housing.
Improve the appearance and performance of the surface, and clean the aluminum liquid.

RUSAL recently stated that it may restrict aluminum exports after the Russian government starts to impose export taxes and fees next month.

Roman Andryushin, the company’s head of domestic and Chinese market sales, said that the company exports about 3 million tons of aluminum each year. This year’s exports may be reduced by hundreds of thousands of tons, because the taxation will make some exports unprofitable.

Russia announced in June that it would impose at least 15% taxes on exports of steel, nickel, aluminum and copper (tax rates vary) from August 1 to curb the surge in commodity prices and boost treasury assets. The Russian government stated that the taxation that lasts until the end of the year will be temporary, and that more sustainable measures will be sought afterwards.

Andryushin believes that the taxation is unfair, because the company will invest billions of dollars to modernize the smelter, and the tax will not significantly reduce local prices, because aluminum accounts for the cost of the Russian construction industry (including state-owned projects) The ratio is relatively small. He also pointed out that Rusal supplies high value-added products to the Russian domestic market and has signed long-term sales contracts.

It is reported that Rusal is unlikely to pass on tax costs to customers, partly because it cannot include these taxes in most long-term agreements. Andryushin said: “If we do this, the market may not buy it, and we will not pay for it. ”

Andryushin said that the tax may mean that Rusal is considering suspending some unprofitable production, and the start of the new Taishet project may be slower than previously expected.
In addition, Rusal expects that aluminum demand will continue to be strong and prices may rise, but may not reach the historical high of more than 3,300 US dollars per ton. The company expects that domestic aluminum sales in Russia will jump 20% this year to 1.2 million tons. Due to economic recovery, major aluminum powers’ measures to restrict supply, and the prospect of increased demand in the electric vehicle and new energy industries, aluminum prices have risen by about 23% this year.

Adtech offers a complete range of rotary degassing unit featuring the latest advancements in technology to meet your metal treatment needs. MMEI degassing product line includes fully automatic ladle degassing stations, in-line units with single and multiple spinning rotors, portable units, and customized units for degassing over-the-road ladles and other large vessels.

Units are available with complete electric and gas controls which are easy to operate and are programmable to ensure repeatable results. Timers, temperature sensors, digital readouts and other enhancements are incorporated into control packages and designed to be operator friendly. MMEI gas controls include separate flow meters for both the purge and main gas. Gas flow is integrated into the electric controls for optimum operation. Gas controls are available for either inert gas or chlorine use.

Each degassing unit is engineered to exceed the difficult demands of the harsh foundry environment and can be custom built to meet your requirements for performance or space limitations.



Melt Aluminum Degassing Unit Price from Adtech is best. Please contact sales@adtechamm.com

As the demand for non-ferrous metal castings continues to increase, foundries are also facing increasing pressure to improve casting quality, especially in the aerospace and automotive industries.

With the demand for aluminum castings, competition among foundries has become increasingly fierce.

Foundries must run the most efficient and cost-effective processes in order to provide competitively priced castings worldwide.

In order to remove impurities and obtain better quality metal, it is best to choose a rotary degassing device.