This guide explores everything you need to know about die cast aluminum alloys.
So, before choosing any aluminum alloy for die casting, read this guide.
This is the most commonly used and popular Aluminum alloy for die casting. It is preferred because of its strong mechanical and physical properties required for die casting.
Such properties include its resistance to corrosion, its lightweight and the fact that its strength can withstand very high temperatures.
Dimensional stability is also retained by A380 Aluminum Alloy despite having thin walls and having complex shapes.
The A380 Aluminum Alloy also has a very good thermal conductivity while still offering a high electrical conductivity.
A Product Made From A380 Aluminum Alloy
A383 Aluminum Alloy is the most widely used option utilized by die casters.
When intricate components that need precise characteristics of die-filling, the A383 Aluminum Alloy is the most preferred in forming them.
It is very strong at very high temperatures and has a very little chance of cracking under intense heat in as much as it has dissimilar properties to the A380 Aluminum Alloy. It is called ADC12.
Motor Vehicle Equipment Made From A383 Alloy
This type of aluminum alloy is hard to die cast compared to A380 meaning die casters avoid it.
Depending on casting abilities and needs, the A360 Aluminum alloy has very good strength at high temperatures.
A360 LED Lamp Housing
This aluminum alloy has a very high hardness and a good resistance to wear.
Its energy is temperately low embodied among all the die cast aluminum alloys.
B390 Die Cast Aluminum Alloy
It is a special type of die cast aluminum alloy that majorly exhibits an excellent pressure tightness property.
Die cast Aluminum A356 Alloy is a very common material in die casting. It comes in three brands namely A356.0; A356.1 and A356.2
A356 Aluminum Cast Pump Housing
This die cast aluminum alloy is applied in situations that require a combination of pressure tightness and high corrosion resistance.
This is a die casting alloy that is patented and has been a game changer for manufacturers and die casters.
This is because surface finishing processes like painting, chromating and anodizing are eliminated.
The elimination of such expensive procedures saves a lot of time and money.
The K Alloy / A304 is designed in such a way that components are protected from damages from the environment that inhibit their performance.
Die casting of Aluminum alloys has been known to produce complex designs not effectively produced by either machining or extrusion.
This is a very expensive surface finish method due to the labor involved. This method gives the die cast aluminum alloy a mirror-like finish.
In the automotive industry, a bright chrome is more commonly used. Satin chrome is also used as it produces a pearlescent appearance.
This is an economical bulk procedure conversion coasting. It is a type of chemical conversion coating whereby a chemical reaction takes place on the die cast aluminum alloy.
The metal surface is transformed into a protective layer by the chemical reaction. This type of surface finish comes in an array of colors.
This is an electrochemical procedure that changes the die cast aluminum alloy surface into a decorative, long-lasting anodic finish that is resistant to corrosion.
Application of this oxide is not like paint or plating on the surface but it is integrated wholly with the die cast aluminum alloy.
This means that it does not peel. It is a very affordable option.
This is a dry coating procedure that is mostly applied in die cast aluminum alloys that are used to manufacture industrial equipment.
Using an electrostatic process, dry powder is applied on the surface to form a powder coating.
Curing is done at very high temperatures hence it has a very tough finish. It is also resistant to scratch and ding.
This process is a form of dipping wet paint finish where electrical current is used to attract paint to the die cast aluminum alloy surface.
It is similar to metal plating but e-coating uses organic paint for the finish instead of particles of metal in the dipping baths.
E-coat can be used alone or as an undercoat for other coatings like powder coat. It usually serves a functional purpose as opposed to decorative.
This is a finishing process whereby a layer of bright nickel is plated over a plating of semi-bright nickel on the surface of the die cast aluminum alloy.
A thin chrome plating application is then used to cover it.
This finish tends to be brittle therefore not recommended for parts that may be crimped or bent just after plating.
This is a finishing process whereby the surface of the die cast aluminum alloy is smoothened by using an abrasive.
It is generally done to increase reflectivity, inhibit contamination improve the appearance of the die cast aluminum alloy.
It acts as the die cast aluminum alloys protective sealant thus improving its durability. It also reduces the wear and tear and corrosion of the die cast aluminum alloy.
A natural coating on the die cast aluminum alloy can be achieved using paint.
When paint is applied to a pre-treated surface, the die cast aluminum alloy will have a great look and can also be customized to suit one’s brand.
Teflon coatings can be applied on the surfaces of die cast aluminum alloys. The surface is roughened in order to obtain optimal adhesion before the coating is applied.
With the exception of mentioned instances, a primer coat is required for these coatings.
A coating of Nickel is deposited on the surface of the die cast aluminum alloy using an auto-catalytic reaction.
Current is not necessarily passed through the solution for deposits to form unlike in electroplating.
This surface finish technique helps to prevent wear and corrosion. Its advantage is that it eliminates power supply issues and it is flux-density free.
Despite the workpiece geometry, an even deposit on the die cast aluminum alloy surface can still be achieved easily.
This type of surface finish is also called conversion coating and is a chemical conversion coating. The surface of the die cast aluminum alloy experiences a chemical reaction.
The alloy surface is then transformed into a protective layer by the chemical reaction.
It provides the die cast aluminum alloy with corrosion protection while leaving a base on the alloys surface for organic coatings.
It also protects the alloy from loss of electrical conductivity.
Chrome Finish Of Die Cast Alloy
Molds are manufactured from very high quality and heat-resistant steel and each mold is specifically designed for each project carried out.
This ensures that each individual component is created with precise accuracy and has repeatability.
The mold design should be considered before anything else.
The design tends to have an impact on the uniformity of a product, its shape, quality and configuration during the die casting process.
Inferior quality products and material corrosion maybe the impact of having a mold with improper specifications.
An effective mold design will ensure efficiency is improved and production time reduced.
The defects in die casted aluminum alloys can be categorized into two; internal and superficial. Internal defects are not easy to find and may result in weakening the structural resistance of the component.
Superficial defects are casting defects that are visible on the surfaces of die cast aluminum alloys.
The defaced the surface of the component and reduce its aesthetic quality.
Turbulences are generated when the fluid moves at high speed on the filling phase. The turbulences are composed of various gases including air.
If the concentration of gas inside the casting is not uniform, cavities will be formed by air bubbles.
The effect will be the weakening of the components resistant sections.
Depending on the type of entrapped gas in the filling stage, the cavities may be opaque or shiny and they are rounded. Lubricant, air and water each have different types of cavities.
These defects occur during the cooling and solidification stages of die casting aluminum alloys.
They occur when the material shrinks and this is the reason why they are extensively spread in substantial parts.
Material have a tendency of moving around colder zones.
Due to the variations in temperature between the core and casting surface, the cavities are focused inside the part.
These are material discontinuities which can be non-metallic or embedded intermetallic phases inside the matrix of the metal.
The various forms of inclusions include liquid droplets, solid articles or films in molten die cast aluminum alloys.
The alloying materials and the value of charge are the determinants of the type and amount of inclusions inside the melt.
Inclusions that are commonly found in die cast aluminum alloys include borides, non-metallic compounds, carbides and oxides.
These defects occur mostly in components that are aesthetical. The different times of solidification of the die cast aluminum alloy is the cause of these defects.
This is because they generate a separate skin on the alloys surface.
The affected area looks fine grained and differs from the rest.
These are the most common die cast aluminum alloys defects found. Their major cause is very low temperatures and irregular flows.
This defects encompasses a varied selection of defects including shortage of material and flow marks.
Alloys will end up with substandard surface quality or worse still it could end up incomplete depending on the rate of defect.
Air within the machine and mold becomes compressed in the mold filling process.
A single part is removed using a vacuum valve from the casting or it overflows.
Homogenous distribution can be used to dissolve the air that remains in the component within the melted metal.
In the event that the component extra operations of high temperatures, blisters are not visible but will diminish the components strength.
High temperature processes like powder painting have an expansion of gases within the casting that expand hence bubbles on the surface are generated.
This defect by extension falls under the category of cold laps. Their major cause is the overlapping of two layers which eventually are separated when filling is done.
Detecting these defects is near impossible but pre-finishing operations such as sand blasting expose them.
Aluminum layers’ experience lifting arising from casting and inserts impact.
These layers tend to hide fluids and die casting process dirt such as oil or lubricant between them.
Such substances worsen the galvanization or painting outcome when they manifest during surface treatment.
This is the breakage of die cast aluminum alloy brought about by stress within and outside the alloy.
The first cracks become visible when solidification and cooling takes place.
The die cast aluminum alloy cannot naturally shrink because of its cavity geometry. This leads to cracks that are brought about by residual stress.
The second cracks arise from external forces acting on the die cast aluminum alloy.
Such forces occur when parts are being ejected from the mold or during the cutting phase.
Heat treatment can be used to modify the property profile of a lot of die cast aluminum alloys in a directed method.
This is applicable to pressure die casting alloys, sand die casting alloys and gravity die casting alloys.
Die cast aluminum alloys manufactured by conventional die casting are bound by limitations with regards to solution annealing.
This is due to the effects of blistering brought about by extreme temperatures.
The lack of knowledge of the range of heat treatment options often leads to poorly defined and incorrect parameters, and improper utilization of the potential of hardenable alloys.
The determinant factors for the selection of the type of heat treatment include the intended purpose, the process of manufacturing and the boundary conditions related to production.
Heat treatment generally leads to an increase in the cost of the end product of die cast aluminum alloys and the turnaround time.
A Heat Treatment System For Die Cast Aluminum Products
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