Aluminium is the world’s most abundant metal and is the third most common element comprising 8% of the earth’s crust. The versatility of aluminium makes it the most widely used metal after steel.
Aluminium Alloys Explained
Aluminium is derived from the mineral bauxite. Bauxite is converted to aluminium oxide (alumina) via the Bayer Process. The alumina is then converted to aluminium metal using electrolytic cells and the Hall-Heroult Process.
Worldwide demand for aluminium is around 29 million tons per year. About 22 million tons is new aluminium and 7 million tons is recycled aluminium scrap. The use of recycled aluminium is economically and environmentally compelling. It takes 14,000 kWh to produce 1 tonne of new aluminium. Conversely it takes only 5% of this to remelt and recycle one tonne of aluminium. There is no difference in quality between virgin and recycled aluminium alloys.
Pure aluminium is soft, ductile, corrosion resistant and has a high electrical conductivity. It is widely used for foil and conductor cables, but alloying with other elements is necessary to provide the higher strengths needed for other applications. Aluminium is one of the lightest engineering metals, having a strength to weight ratio superior to steel.
By utilising various combinations of its advantageous properties such as strength, lightness, corrosion resistance, recyclability and formability, aluminium is being employed in an ever-increasing number of applications. This array of products ranges from structural materials through to thin packaging foils.
Aluminium is most commonly alloyed with copper, zinc, magnesium, silicon, manganese and lithium. Small additions of chromium, titanium, zirconium, lead, bismuth and nickel are also made and iron is invariably present in small quantities.
There are over 300 wrought alloys with 50 in common use. They are normally identified by a four figure system which originated in the USA and is now universally accepted. Table 1 describes the system for wrought alloys. Cast alloys have similar designations and use a five digit system.
Table 1. Designations for wrought aluminium alloys.
Alloying Element Wrought None (99%+ Aluminium) 1XXX Copper 2XXX Manganese 3XXX Silicon 4XXX Magnesium 5XXX Magnesium + Silicon 6XXX Zinc 7XXX Lithium 8XXXFor unalloyed wrought aluminium alloys designated 1XXX, the last two digits represent the purity of the metal. They are the equivalent to the last two digits after the decimal point when aluminium purity is expressed to the nearest 0.01 percent. The second digit indicates modifications in impurity limits. If the second digit is zero, it indicates unalloyed aluminium having natural impurity limits and 1 through 9, indicate individual impurities or alloying elements.
For the 2XXX to 8XXX groups, the last two digits identify different aluminium alloys in the group. The second digit indicates alloy modifications. A second digit of zero indicates the original alloy and integers 1 to 9 indicate consecutive alloy modifications.
Aluminium has a density around one third that of steel or copper making it one of the lightest commercially available metals. The resultant high strength to weight ratio makes it an important structural material allowing increased payloads or fuel savings for transport industries in particular.
Pure aluminium doesn’t have a high tensile strength. However, the addition of alloying elements like manganese, silicon, copper and magnesium can increase the strength properties of aluminium and produce an alloy with properties tailored to particular applications.
Aluminium is well suited to cold environments. It has the advantage over steel in that its’ tensile strength increases with decreasing temperature while retaining its toughness. Steel on the other hand becomes brittle at low temperatures.
When exposed to air, a layer of aluminium oxide forms almost instantaneously on the surface of aluminium. This layer has excellent resistance to corrosion. It is fairly resistant to most acids but less resistant to alkalis.
The thermal conductivity of aluminium is about three times greater than that of steel. This makes aluminium an important material for both cooling and heating applications such as heat-exchangers. Combined with it being non-toxic this property means aluminium is used extensively in cooking utensils and kitchenware.
Along with copper, aluminium has an electrical conductivity high enough for use as an electrical conductor. Although the conductivity of the commonly used conducting alloy (1350) is only around 62% of annealed copper, it is only one third the weight and can therefore conduct twice as much electricity when compared with copper of the same weight.
From UV to infra-red, aluminium is an excellent reflector of radiant energy. Visible light reflectivity of around 80% means it is widely used in light fixtures. The same properties of reflectivity makes aluminium ideal as an insulating material to protect against the sun’s rays in summer, while insulating against heat loss in winter.
Table 2. Properties for aluminium.
Property Value Atomic Number 13 Atomic Weight (g/mol) 26.98 Valency 3 Crystal Structure FCC Melting Point (°C) 660.2 Boiling Point (°C) 2480 Mean Specific Heat (0-100°C) (cal/g.°C) 0.219 Thermal Conductivity (0-100°C) (cal/cms. °C) 0.57 Co-Efficient of Linear Expansion (0-100°C) (x10-6/°C) 23.5 Electrical Resistivity at 20°C (Ω.cm) 2.69 Density (g/cm3) 2.6898 Modulus of Elasticity (GPa) 68.3 Poissons Ratio 0.34Aluminium can be severely deformed without failure. This allows aluminium to be formed by rolling, extruding, drawing, machining and other mechanical processes. It can also be cast to a high tolerance.
Alloying, cold working and heat-treating can all be utilised to tailor the properties of aluminium.
The tensile strength of pure aluminium is around 90 MPa but this can be increased to over 690 MPa for some heat-treatable alloys.
Table 3. Mechanical properties of selected aluminium alloys.
Alloy Temper Proof Stress 0.20% (MPa) Tensile Strength (MPa) Shear Strength (MPa) Elongation A5 (%) Elongation A50 (%) Hardness Brinell HB Hardness Vickers HV Fatigue Endur. Limit (MPa) AA1050A H2 85 100 60 12 30 30 H4 105 115 70 10 9 35 36 70 H6 120 130 80 7 39 H8 140 150 85 6 5 43 44 100 H9 170 180 3 48 51 0 35 80 50 42 38 21 20 50 AA2011 T3 290 365 220 15 15 95 100 250 T4 270 350 210 18 18 90 95 250 T6 300 395 235 12 12 110 115 250 T8 315 420 250 13 12 115 120 250 AA3103 H2 115 135 80 11 11 40 40 H4 140 155 90 9 9 45 46 130 H6 160 175 100 8 6 50 50 H8 180 200 110 6 6 55 55 150 H9 210 240 125 4 3 65 70 0 45 105 70 29 25 29 29 100 AA5083 H2 240 330 185 17 16 90 95 280 H4 275 360 200 16 14 100 105 280 H6 305 380 210 10 9 105 110 H8 335 400 220 9 8 110 115 H9 370 420 230 5 5 115 120 0 145 300 175 23 22 70 75 250 AA5251 H2 165 210 125 14 14 60 65 H4 190 230 135 13 12 65 70 230 H6 215 255 145 9 8 70 75 H8 240 280 155 8 7 80 80 250 H9 270 310 165 5 4 90 90 0 80 180 115 26 25 45 46 200 AA5754 H2 185 245 150 15 14 70 75 H4 215 270 160 14 12 75 80 250 H6 245 290 170 10 9 80 85 H8 270 315 180 9 8 90 90 280 H9 300 340 190 5 4 95 100 0 100 215 140 25 24 55 55 220 AA6063 0 50 100 70 27 26 25 85 110 T1 90 150 95 26 24 45 45 150 T4 90 160 110 21 21 50 50 150 T5 175 215 135 14 13 60 65 150 T6 210 245 150 14 12 75 80 150 T8 240 260 155 9 80 85 AA6082 0 60 130 85 27 26 35 35 120 T1 170 260 155 24 24 70 75 200 T4 170 260 170 19 19 70 75 200 T5 275 325 195 11 11 90 95 210 T6 310 340 210 11 11 95 100 210 AA6262 T6 240 290 8 T9 330 360 3 AA7075 0 105 225 150 17 60 65 230 T6 505 570 350 10 10 150 160 300 T7 435 505 305 13 12 140 150 300The old BS1470 standard has been replaced by nine EN standards. The EN standards are given in table 4.
Table 4. EN standards for aluminium
Standard Scope EN485-1 Technical conditions for inspection and delivery EN485-2 Mechanical properties EN485-3 Tolerances for hot rolled material EN485-4 Tolerances for cold rolled material EN515 Temper designations EN573-1 Numerical alloy designation system EN573-2 Chemical symbol designation system EN573-3 Chemical compositions EN573-4 Product forms in different alloysThe EN standards differ from the old standard, BS1470 in the following areas:
A range of heat treatments can be applied to aluminium alloys:
The non-heat treatable alloys are those in the 3XXX, 4XXX and 5XXX groups.
Table 5. Heat treatment designations for aluminium and aluminium alloys.
Term Description T1 Cooled from an elevated temperature shaping process and naturally aged. T2 Cooled from an elevated temperature shaping process cold worked and naturally aged. T3 Solution heat-treated cold worked and naturally aged to a substantially. T4 Solution heat-treated and naturally aged to a substantially stable condition. T5 Cooled from an elevated temperature shaping process and then artificially aged. T6 Solution heat-treated and then artificially aged. T7 Solution heat-treated and overaged/stabilised.The non-heat treatable alloys can have their properties adjusted by cold working. Cold rolling is an example.
These adjusted properties depend upon the degree of cold work and whether working is followed by any annealing or stabilising thermal treatment.
Nomenclature to describe these treatments uses a letter, O, F or H followed by one or more numbers. As outlined in Table 6, the first number refers to the worked condition and the second number the degree of tempering.
Table 6. Non-Heat treatable alloy designations
Term Description H1X Work hardened H2X Work hardened and partially annealed H3X Work hardened and stabilized by low temperature treatment H4X Work hardened and stoved HX2 Quarter-hard – degree of working HX4 Half-hard – degree of working HX6 Three-quarter hard – degree of working HX8 Full-hard – degree of workingTable 7. Temper codes for plate
Code Description H112 Alloys that have some tempering from shaping but do not have special control over the amount of strain-hardening or thermal treatment. Some strength limits apply. H321 Strain hardened to an amount less than required for a controlled H32 temper. H323 A version of H32 that has been hardened to provide acceptable resistance to stress corrosion cracking. H343 A version of H34 that has been hardened to provide acceptable resistance to stress corrosion cracking. H115 Armour plate. H116 Special corrosion-resistant temper.
DISCLAIMER
This Data is indicative only and must not be seen as a substitute for the full specification from which it is drawn. In particular, the mechanical property requirements vary widely with temper, product and product dimensions. The information is based on our present knowledge and is given in good faith. However, no liability will be accepted by the Company is respect of any action taken by any third party in reliance thereon.
As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose.
Any advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. Any contract between the Company and a customer will be subject to the company’s Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.
This information has been sourced, reviewed and adapted from materials provided by Aalco - Ferrous and Non-Ferrous Metals Stockist.
For more information on this source, please visit Aalco - Ferrous and Non-Ferrous Metals Stockist.
Before choosing A380 aluminum alloy for any die casting process, you should understand various properties of this metal.
Today’s guide will answer all questions you have been asking about A380 aluminum alloy.
So keep reading to learn more.
Die Casting A380 aluminum alloy
Heat treatment is prevented from refining the die castings mechanical properties by defects of air entrapment.
This will in turn inhibit the function of high performance components in the die casting.
The filling process has a very complex flow pattern and the thin-walled die castings make experimental analysis very challenging.
During the filling process, pure aluminum had a larger degree of breakup compared to that of A380 Aluminum Alloy.
This leads to increased porosity of pure aluminum. The varied porosity between pure Aluminum and A380 Aluminum Alloy is can be attributed to the aluminum liquids flow state.
High pressure die casting (HPDC) also comes with its limitations when it comes to the flow state of Aluminum.
Since the filling time is exceptionally brief, pores are formed due to the gas trapped in the process of high-speed injection.
The effect of porosity is that the properties of heat treatment of castings are greatly hindered therefore the quality of casting is degraded.
During the filling process, differences between A380 Aluminum Alloy and pure Aluminum were majorly brought about by the continuous aluminum liquid degree of cracking.
More rapture is observed on pure Aluminum while the A380 Aluminum Alloy remains considerably continuous with a slight degree of rapture.
These systems are utilized to provide an ornamental finishing in the A380 Aluminum Alloy.
They also form a protective layer that protects the alloy against extreme exposures in the environment while improving its wear resistance.
Some of the ways of applying the decorative finishes are through plating, painting, epoxy finishing or by powder coat finishing.
When plating the A380 Aluminum Alloy, an immersion zinc coating is applied before copper-nickel-chromium plating.
Chromating, painting, anodizing and the use of iridite coatings can be used to achieve protection from corrosion caused by the environment.
Hard anodizing can be used to greatly improve the resistance to wear and tear of the A380 Aluminum Alloy.
In the event that a part restricts pressure-tight production of an A380 Aluminum Alloy casting and overflow die design, then the aluminum die cast can either be impregnated.
Pressure tight and sealed castings with smooth surface finishes can be produced by applying methacrylates and aerobic systems.
Aluminum can be described as a thermodynamically reactive metal as is exhibited by its electromotive force series position.
The only metals that are more reactive than it are magnesium and beryllium.
An oxide film strongly bound on the aluminum surface serves as an excellent barrier against corrosion and making it the metal of choice in commerce.
At ambient temperatures, a surface film is normally formed in air and is only about 5 nm thick.
Once damaged, the thin film will re-form instantaneously and it will continue protecting the A380 Aluminum Alloy from corrosion.
When the damage is such that self-repair becomes impossible, then corrosion will occur.
The A380 Aluminum Alloys corrosion resistance largely relies on both environmental metallurgical and environmental variables.
Mechanical working and optimum selection of temper also known as heat treatment are some of the metallurgical variables affecting the composition.
They are the microstructure determinants and choose the method of attack of corrosion and whether the localized corrosion occurs.
Corrosion is affected by both physical and chemical environments of the A380 Aluminum Alloy.
The environmental chemical influence mostly relies on impurities present such as heavy metal ions and its composition.
The physical variables include pressure, temperature, agitation and the degree of movement.
Based on the fact that corrosion of the A380 Aluminum Alloy is influenced by various variables, its suitability cannot be based solely on environment or specific product.
An in-depth familiarity of the equipment’s design, the microstructure of the A380 Aluminum Alloy and the operational conditions is essential.
A380 aluminum alloy bars
Modern manufacturers are currently opting for lightweight materials which can withstand extreme temperatures and dynamic loads.
High pressure die casting (HPDC) alloys are finding more applications in the automotive and aviation industries replacing A380Aluminum Alloy.
This is because of their striking properties like diecastability, ability to integrate designs, their damping capacity and an extremely high stiffness /weight ratio.
Such HPDC alloys have applications in safety related uses such as seats and doors, steering wheels etc.
The A380 Aluminum Alloy strength is attributed to its capacity to impede dislocation motion.
The mechanisms involved in strengthening are associated with precipitates, the size of the grain and solute atoms.
The enhanced distribution of the second phases has led to better casting mechanical properties with smaller grains.
Solute atoms in the parent lattice, which are positioned either substitutionally or interstitially, produce stress fields which hinder dislocation motion.
Quenching and solution treatment are the methods used to produce precipitates that are used for strengthening.
This process is followed by ageing whereby the precipitates and atoms in the precipitates solid solution, at elevated temperatures, inhibit dislocation motion.
Adding dispersions (hard particles) also strengthens alloys.
If the A380 Aluminum Alloy has minimal solubility, then growth will be inhibited by dispersions and they remain small even at escalated temperatures.
Some of the key alloying element are:
Advantages of alloying with silicon include a high abrasive wear resistance, improved castability and increased strength.
Copper alloys have improved properties and respond extremely well to thermal treatment.
No substantial gain is derived from zinc in an A380 Aluminum Alloy. However, it leads to naturally ageing and heat treatable compositions.
Hot tear resistance is enhanced and soldering and die sticking tendencies reduced when alloying with iron. An increase in iron content leads to a decrease in ductility.
In casting compositions, it is usually taken as an impurity therefore its levels are controlled to minimum.
To increase alloy strength at elevated and room temperatures, nickel is added. It also enhances the hardness and strength of alloys.
It enhances anti-friction characteristics in moving automotive applications. Under emergency situations, it exudes and provides temporary liquid lubrication.
In heat treated alloys, it is the source of hardness development and strength.
The system in use is a 4-digit identification system for wrought Aluminum alloy.
The principal alloying element is the first digit (Xxxx) which is added to the alloy and describes the alloy series e.g. 2000 series.
Alloy designation system
Modification of the alloy is represented by the second digit (xXxx) while exact alloys in the series are given arbitrary numbers in the third and fourth digits (xxXX).
For cast alloys, a three digit with decimal is used. The principal alloying element is shown by the first digit (Xxx.x).
Specific alloys are identified by the second and third arbitrary digits (xXX.x). If the alloy is a casting it wil be .0 and an ingot will be .1
The A380 Aluminum Alloy is considered among commercial alloys that easily heat treatable.
The purpose of heat treatment is mainly to improve the alloys mechanical structure, changing its microstructure or eliminating residual stress.
Heat treating A380 Aluminum Alloy also increases the ease at which it forms.
The use of special equipment is necessary since aluminum needs unyielding heat control for optimal results to be achieved.
With an elastic modulus of around 70 GPa, the A380 Aluminum Alloy has around a third of other conventional alloys elastic modulus.
This means that A380 Aluminum Alloy undergoes a bigger deformation under load in the elastic region compared to other conventional alloys.
Generally, A380 Aluminum Alloy offers designs that are lighter and stiffer that cannot be easily achieved with other metal alloys and sometimes completely not feasible.
An example is in the aviation industry where planes use extruded profiles to make space frames that ensure rigidity unlike other metal alloys which enhance stiffness by relying on body shells.
Imperfections in the A380 Aluminum Alloy may contain flaws like porosity, intermetallics and oxides. They may also include microstructural feature dimensions such as eutectic.
The tensile properties of the A380 Aluminum Alloys are affected by the eutectic Silicon (Si) but is majorly not considered as a defect.
Imperfections tend to lead to premature failures.
Some of the imperfections in aluminum die casting these alloys include:
Imperfection on die cast aluminum part
Depending on their thermal history and chemical composition, eutectic silicon may have varied morphologies.
The distribution and morphology of eutectic silicon on A380 Aluminum Silicon is very significant because they are the possible initiation sites where fractures occur.
Low solubility of iron in the A380 Aluminum Alloy leads to formation of intermetallics.
The most common intermetallics are generated by iron in casting alloys.
Iron has a solubility of around 0.03-0.05% at 655° in solid A380 Aluminum Alloy which can go lower when at room temperature.
Complex plate structures in 3D called ß-Fe are formed when iron combines with silicon and aluminum.
The ß-Fe intermetallics adversely affect the mechanical properties of A380 Aluminum Alloy like the reduction in ductility. This will in turn lead to a reduction in the ultimate tensile strength.
A380 Aluminum Alloy readily oxidizes forming a layer of aluminum oxide on the liquid and solid surfaces that are in contact with oxygen in the atmosphere.
The oxides have a surface growth on the A380 aluminum surface and the layer becomes bigger thus slowing down the growth rate because less oxygen diffuses through the layer.
When the flow of liquid metal is too fast during casting, waves may be generated on the surface. When surface turbulence becomes extreme, the waves peaks fold on the surface and entrench surface oxides.
Bonding to the liquid will be retained by the oxides but there will be no bonding between the two dry surfaces.
This leads to the entrained oxide acting as a crack.
The three major causes of porosity in A380 Aluminum Alloy are entrapped air, hydrogen and shrinkage due to solidification.
The only gas with a substantial solubility in aluminum is hydrogen and is much lower when its solid.
During solidification, the hydrogen content increases in the remaining liquid.
The level of hydrogen is most likely to surpass solubility limit if it is unable to leave the casting and this leads to porosity formation.
Shrinkage pores can normally be seen as intermediate empty regions. The density of cast aluminum increases when they solidify.
Neighboring volumes feed the shrinkage with liquid through the interdentritic channels as the casting regions begin to solidify.
The tension built up during shrinkage will be emitted by formation of porosity in the event that the volumes are not well fed.
A combination of gas and shrinkage is usually responsible for most of the porosity in A380 Aluminum Alloy.
They are both aluminum alloys with their alloy composition having a 92% similarity.
In application, A380 Aluminum Alloy is normally used for tool parts, to make brackets, furniture and motor shell.
A356-T is generally used to make structure parts such as belt pulley, parts of pumps and machine casings.
A380 Aluminum Alloy has optimum machining properties and suitable for die casting and sand casting.
A356-T cannot be easily machined hence suitable with sand casting and permanent mold casting.
The differences in mechanical properties include;
A380 Aluminum Alloy,
A356-T,
The A380 Aluminum Alloy has been confirmed to meet all the density targets and mechanical property targets.
For thus alloy, the eventual tensile strength is usually 47 ksi while its yield strength is normally 23 ksi.
Also, the A380 Aluminum Alloys thermal conductivity is unfortunately 20% below the target design.
The A380 Aluminum Alloy is a high temperature alloy. It can safely withstand temperatures of around 300°C.
We also have other Aluminum alloys which have a higher temperature tolerance than the A380 Aluminum Alloy.
Such alloys include the A4032 and A2618 which are normally utilized in the manufacture of high performance pistons and other components like aerospace airframes.
A lot of strength is lost by these alloys when the temperature exceeds 300°C.
Powder processed Aluminum alloys have been developed to overcome such shortcomings. It is foreseen that Titanium or Steel could be replaced by such advanced high temperature alloys.
They exhibit remarkable thermal stability at service temperature even after operating over hundreds of hours of operation.
This makes them more efficient in terms of performance compared to A380 Aluminum Alloy and others like A2618 and 4032 which are high temperature alloys.
Squeeze casting is a combination of both forging and casting.
During solidification, the melt is exposed to high pressures and very fine grains are obtained in the process thus preventing shrinkage porosity.
The significance of squeeze casting A380 Aluminum Alloy is for it to have a rheological solidification under pressure when still in liquid state.
This process also leads to microstructure evolution since it affects the feeding and its microstructure in turn.
Squeeze casting also assists in initiating the solidification nucleation, controlling the nucleation and inhibiting the growth of dendrites.
Fewer air bubbles are trapped inside the A380 Aluminum Alloy when squeeze casting is applied.
This increases its quality and performance traits since they can handle shrinkage more efficiently.
Composite fibers can also be used by manufacturers in squeeze casting without interfering with the quality of the alloy.
This is because ferrous alloys and materials are allowed for use in squeeze casting.
Squeeze casting an A380 Aluminum Alloy does not emit any gases to the atmosphere.
This is in addition to the fact that there is significant control on the structures final look due to its cooling rate.
ADC 10 is the equivalent of the A380 Aluminum alloy. It is also an aluminum alloy that is widely used in the making of die castings.
Products casts made from ADC10 function well in presses and don’t splinter or crack as experienced in other metals. In addition, its anti-soldering properties ensure extended life of dies and tools.
A380 aluminum alloy die cast part
Some of the most common machines and equipment are:
The K-Alloy/A304 was first introduced into the market in 2003 and patented as a casting aluminum alloy.
Processes like painting, anodizing and chromating have been eliminated when the use of the K-Alloy/A304 is applied.
Time and money is saved by eliminating such expensive procedures in addition to K-Alloy/A304 offering reliable protection from harsh environmental conditions.
This ensures effective performance as damages are greatly minimized.
Besides its exceptional resistance to corrosion, the K-Alloy/A304 also has great elongation properties with improved thermal conductivity.
Compared to the A380 Aluminum Alloy, the cooling rate of K-Alloy/A304 is 15% better.
Compared with A380, K-Alloy/A304 has the same die life in addition to having similar shrink factors with other castings.
However, it still possesses a higher finish quality for applications with high polish while eliminating the use of process parameters or any special tool.
The various applications of the K-Alloy/A304 include housing vehicle structural parts and also electronic modules.
Stadium lighting systems and military applications like drones and antennas are also some of the commercial applications of K-Alloy/A304.
In case you have any questions about A380 aluminum alloy die casting, talk to us now.