When we talk about Aluminum casting methods this one differs from the manufacturing proccess that it will undergo like from sand casting, pressure die casting, die casting, shell mold casting, continous casting and many more. There are advantages and disadvantages when the aluminum casting has go with the process. People can choose the casting’s complexity and size and it the suitable method that goes along with it.
When it comes to serving different industries, Aluminum is the one that is mostly chosen for both non-industrial and industrial uses. To be able to decide the suitable technology one should remember that quality is the key to all of it. This should not be doubted because when we talk about “How to cast aluminum part” it is only right to go for aluminum foundries that use various casting technologies.
In order to understand and know the casting quality, both inside and outside measures are needed plus the strength and ductility. Professionals or engineers should always advocate for the advantages then make sure to solve the disadvantages in relation to the aluminum casting method. This will improve the quality of the work and more customers satisfaction can be obtained with the good work.
Things to know about aluminum casting methods
1. Aluminum sand casting
Sand casting is one of the oldest casting strategies, dating back about 2,000 years in history. Sand casting has been used for forged aluminum since the beginning of the 20th century when metallic aluminum became known to human. When casting aluminum in sand molds, the sand and binders cause mold. The style is placed in a mold and pressed firmly. After peeling off the template, it made a hollow mold space. This is a reproduction of an aluminum casting mold. Through the gating system, molten aluminum is poured into the cavity of the mold and solidified. And as the casting is cooled down, the caster breaks the sand mildew, and the casting is collected. Nowadays, enhancements in the sand casting era have extended the burden and common length of aluminum sand casting. Many sand-casted aluminum gadgets are weighing extra than 50kg, even a few casting as huge as 100m3.
Advantages of aluminum sand casting
·Being flexible to fabricate small and large castings.
·Various aluminum assesses can be processed sand cast, which includes alloys with hot shortness.
·The Green sand has a low compressive asset, it minimizes the risk of hot cracking defects.
·It can adjust the design pattern.
Disadvantages of aluminum sand casting
·One of the disadvantages is the surface is not that smooth bit can be treated with sandblasting so that the surface can be enhanced to the needed quality.
• Cast sizes have higher tolerances than other aluminum casting methods.
Applications of aluminum sand casting
Mentioning the application for most aluminum and sand casting application is hard due to the reason that the process can manufacture almost all parts of all sizes.
If you have a moderate budget and want to cast aluminum products that do not have too high a requirement on surface finish, then the sand casting method is the number one choice.
When you have the means or money and chose to cast aluminum products which doesn’t require much higher finishing a surface, then the sand casting method is the preferred choice to do it.
2. Aluminum Pressure die casting
Die casting has two types and this is aluminum high-pressure die casting and aluminum low-pressure die casting.
High-pressure Aluminum die casting
When we talked about high-pressure Aluminum Die casting it means that it is the aluminum casting process that can fabricate casting parts through pressing aluminum fluid under high pressure that is approximately 1200 bar then into a steel mold through a cylinder-pistol. Then the liquid aluminum is pumped at high speed then it solidifies speedily to form the aluminum casting parts that is impressive.
There are two types of cast chambers in high-pressure aluminum die casting:
The Hot Chamber – this is a casting chamber to which the cylinder and pistol are found in the furnace system and have the same temperature as the melting point of an aluminum alloy.
The Cold Chamber – this is a casting chamber wherein the molten aluminum alloy is put into the cylinder after which the piston pushes the metal to the mold with great pressure. Remember the pistol is not placed in the oven that is why it is considered to be cool and this is mainly used for aluminum alloys.
When it comes to mass production of small details the aluminum high pressure die casting is the right choice and this weighs about 5kg with a thin cutting surface of about 0.4mm thickness. When it becomes larger, the cost gets higher.
Low-pressure aluminum die casting
When we talk about the low-pressure aluminum die casting, take note that the mold is filled with liquid metal from a pressure-adjustable crucible (usually 0.7bar). Metal annealing furnace can be found below (instead of horizontally like high-pressure aluminum dies casting), then the molten aluminum is pumped directly from the bottom up so that it can fill the mold. Then Aluminum low-pressure die casting process is appropriate for manufacturing aluminum casting parts that have a wall thickness of 3mm or more, plus the volume can be up to 150kg. Talking about die casting, aluminum alloy is among the most often cast metal, it is accouted twice the other metal casting methods use.
Types of aluminum alloys used in die casting method
·380.0 (Al + Si + Cu + Mg): cast aluminum alloy, high mechanical strength, good corrosion resistance, high dilution, low price. Often used to cast gearboxes. This type of alloy accounts for 85% of the aluminum alloy being used in press die aluminum casting today.
·A360.0 (reduce the amount of Cu): high-grade cast-aluminum alloy, fewer impurities, better corrosion resistance than 380. Used to cast musical instruments, anti-corrosion details.
·413.0 (Al + Si): cast alloy, better corrosion resistance than 360. Often used to cast pistol, crankshaft.
·518 (Al + Mg): the best ingot (ingot) alloy, with the best wear resistance, but low dilution and difficult to cast, high cost.
The advantages of die casting
·It has a tight tolerance for aluminum casting.
·Its surface is shiny and smooth, then it has a few defects on the surface thus making the product easier when applying paint coating.
·Then aluminum grains have a tighter texture, small and dense, it is also smooth which helps the casting to have high mechanical properties in order to have good wear resistance.
·It is also suitable for automatic production lines.
The disadvantages of die casting
• Because molten aluminum is pumped at excessive velocity and cools fast, it entrains the condensate into the casting, making it tough to weld and warmth treatment. To deal with fuel lines trapped withinside the casting, the foundry can use vacuum descaling technology. Aluminum alloys with a quick freezing temperature variety must be selected.
• Investment value for the operation and mildew is expensive, simplest appropriate for big order quantities.
• It could be very tough to modify the product layout because of the sand casting method.
• Due to the excessive-strain alloy flow, the mildew is fast worn out.
Applications of die casting
This aluminum casting procedure has a extensive variety of packages from easy additives inclusive of lights additives to complicated additives inclusive of engines, transmission housings, wheels, car suspension, and spacecraft.
3. Shell mold aluminum casting
Shell molding is a molding era with a mold crafted from thermosetting phenolic resin.
First, the two halves of patterns are format and comprised of metal, and then bareheaded and covered with lubrication. Then region the pattern into the thermoset sand chamber prepared above and then turn it upside down. The mixture of resin sand sticks to the pattern hardens to form a shell. The pattern is removed, leaving a shell. Two halves of the pattern will form shell molds about 10-20 mm thick. These shell molds are assembled to form an entire mold. Liquid aluminum is poured into the mildew and solidified proper right into a casting form. At this point, definitely breaking the shell of the mildew then we’re capping a position to build up the casting.
Shell mold aluminum casting is one of the aluminum casting techniques that is suitable for the fabrication of hollow-middle or die castings.
The advantages of shell mold casting
• The perfection degree of the floor end is exceptionally high.
• The length of the casting is greater accurate; the tolerance is tight.
• The sample is reusable.
The disadvantages of shell mold casting
• High manufacturing costs.
• With huge and complicated castings, it won`t be smooth to cast.
Shell mold casting applications
This aluminum casting method is relevant for casting Cylinder heads, connecting rods, engine blocks, manifolds, system bases, truck hoods, valve bodies, etc.
4. Permanent mold aluminum casting
Permanent mould aluminum casting, moreover referred to as metallic mould casting, is one of the aluminum casting techniques that use metallic as the mould fabric similarly to the pressure die casting. Accordingly, the liquid aluminum is pushed into the mould with the useful resource of the use of its gravity, so the pouring speed is quite low. Due to the metallic-made mould, the casting cooling speed is fast. Molds have an extended service life, so they`re known as eternal molds. Permanent mould aluminum casting is suitable for casting hundreds more than immoderate-pressure die casting, about 10kg. The higher the volume, the more high-priced the cost. If combined with the warm temperature treatment techniques, the mechanical homes of metallic molds will increase. Small castings will cool quickly, so no warm temperature treatment is required. For maximum mechanical homes, cope with a completely unique solution at immoderate temperatures, then cool and allow natural or artificial aging.
The aluminum alloy used in Permanent mold aluminum casting
·366: manufacturing pistols and cars.
·355.0, C355.0, A357.0: manufacturing gearboxes, for high-strength components such as rocket parts.
·356.0, A356.0: machine parts, aircraft wheels, …
The advantages of permanent mold aluminum casting
• The aluminum casting houses are immoderate due to the fast cooling rate of the casting.
• Low aluminum shrinkage rate and fuel line porosity defect. Dimension tolerance is first-class about 1mm.
• Good ground first-class 1-6 µm Ra.
• Less scrap.
The disadvantages of permanent mold aluminum casing
• High cost.
• Difficult to make aluminum casting merchandise with excessive complexity and huge size.
• Difficult to regulate the product design.
The permanent mold aluminum casting applications
In the vehicle industry, developing additives like gears, castings, suspensions, fuel line injection housings, and engine pistons. Aircraft additives are also frequently made thru eternal mold aluminum casting.
This aluminum casting way is used withinside the car and aircraft industries to create additives, at the side of gears, suspensions, pistols, fuel line housing, etc.
5. Aluminum Investment casting
Aluminum Investment casting, moreover called aluminum out of place wax casting, is the casting aluminum method thru the manner of setting wax or thermoplastics proper right into a prefabricated metallic or rubber mold. Wax patterns are accumulated and assembled to form a tree branch connected to the gating tool to stable withinside the same batch. The wax pattern will now be applied investment with refractory materials. This device is repeated until the outer sheath reaches a thickness of 5-15mm. This shell is the investment mold. Then dry and heat the tree just so the wax internal is melted out, leaving the inner chamber of the mildew withinside the shape of the popular casting. The investment mold is then heated in advance than pouring aluminum fluid. Any cracks that appear withinside the mildew can be repaired with ceramic or particular materials. Molten aluminum is poured into the mildew after it dries up best to damage the outer ceramic shell. The casting is removed from the tree and surpassed to the finishing device.
Advantages of Aluminum Investment casting
• High-quality surface, high dimensional accuracy.
• It is possible to cast complex aluminum castings.
• Many aluminum castings are cast simultaneously.
Disadvantages of Aluminum investment casting
• High production costs.
• Casting with a core is difficult and difficult to cast.
• Longer production cycles are required.
• Generally only suitable for small cast aluminum parts.
Aluminum Investment casting applications
Investment casting technology has many applications, such as the production of aluminum castings in the aerospace, power, weapons, automotive, military, gas, and petroleum industries.
6. Aluminum Centrifugal Casting
Centrifugal aluminum casting is an aluminum casting process in which molds are made from metal, gypsum, or graphite. Molten aluminum is poured into the mold from the outside while rotating the mold in a centrifugal casting machine. Liquid aluminum is evenly distributed on the mold wall by centrifugal force and hardens according to the shape of the mold. There are two types of centrifugal casting molds: vertical axis centrifugal casting molds and horizontal axis centrifugal casting molds. The mold rotation motor rotates the mold to evenly distribute the metal on the mold surface.
The advantages of aluminum centrifugal casting
• The size of the aluminum casting is very accurate due to the limited centrifugal force and the metal is tightly closed.
• Aluminum castings have high mechanical properties and a small microstructure outside the metal.
• It is not necessary to use the core, but it can be emptied in the middle, which can reduce the cost of core production.
• No potting system is required to save metal.
The disadvantages of Aluminum Centrifugal Casting
• The inner surface of centrifugal cast aluminum parts is poorly finished, dusty, and the inner diameter is not accurate.
• Generally only suitable for casting round or cylindrical aluminum parts. Castings with complex shapes must be combined with methods of casting with shell molds.
Centrifugal casting applications
Centrifugal casting is used in aluminum foundries to produce jet engine compressor parts, petrochemical furnaces, and aluminum castings for various types of military and defense equipment.
7. Aluminum Continuous casting
Aluminum continuous casting is a casting process in which an aluminum alloy is continuously poured into a mold using a circulating water cooling system. Wherever a casting is made, it is immediately cooled and removed. Directly behind the casting system are a continuous stamping and rolling line. Cast products are aluminum rods, plates, or pipes up to 0.2×1 m in size. It is a very efficient casting system and is widely used in aluminum and steel foundries.
The advantages of continuous casting
• Aluminum continuous casting has high mechanical properties due to rapid cooling.
• Ease of automation leads to high productivity.
• The surface of the casting is ideal and the metal particles are densely distributed.
The disadvantages of Aluminum continuous casting
• Only suitable for aluminum castings with simple shapes.
• Objects with cross-sectional lengths cannot be cast.
• High initial construction costs.
Aluminum Continuous casting applications
Aluminum continuous casting is used for casting metal rods, metal pipes of various sizes. There are also several other aluminum casting methods used to make aluminum castings, such as the vacuum casting process, ablation casting, investment casting, etc. It also has many advantages similar to the casting process described above.
Considering suitable aluminum casting technologies
Each aluminum casting process has advantages and disadvantages. The information in this article compares the various aluminum castings and then selects the requirements for the type, accuracy, and annual product performance from the aluminum casting budget. Many other factors influence the choice of aluminum casting technology. However, thanks to the information provided in the article, VIC is a rather reasonable solution as well as a better understanding of how to cast aluminum. VIC has metal coil systems with a variety of machining technologies. Especially in aluminum casting, VIC adopts wet sand casting and gasification casting technology and expands the production line to other casting technology to meet market requirements. VIC is pleased to work with partners around the world to help customers sell metal casting products at an affordable price and high quality.