Tlpcasting is a Aluminum Die Casting Manufacturer
Weight: 0.5kg – 1000kg
Capability: 50 ton per month
Machining tolerance: +-0.01-0.03mm
Surface Roughness: 3.2 Ra um/125 Ra uinches
MOQ: 500 pcs
Aluminum Alloy Materials
The A380 is one of the most widely used aluminum alloys and has many obvious advantages:
- It combines casting, mechanical and thermal properties perfectly
- It has excellent fluidity, gas tightness and heat cracking property
The alloy is used in a variety of products, such as electronic equipment chassis, engine brackets, gearbox housing, household furniture, power hand tools.
The mechanical properties
|Tensile Strength (MPa)||Yield Strength (MPa)||Shock Strength|
|Thermal Conductivity (W/Mk)||Density|
|Coefficient of Thermal Expansion|
If you have extremely complex parts, the 383 is usually used as a replacement for the A380.
It has superior corrosion resistance and is lightweight. Its advantages include ease of casting, excellent mechanical properties, and dimensional stability.
The mechanical properties.
|Tensile Strength (MPa)||Yield Strength (MPa)||Shock Strength|
|Thermal Conductivity (W/Mk)||Density|
|Coefficient of Thermal Expansion|
Die-cast aluminum alloy features
Aluminum castings are lightweight and can withstand the highest operating temperatures of all die-casting alloys.
Characteristics of aluminum alloy:
- High operating temperature
- Excellent corrosion resistance
- Good strength and hardness
- Good stiffness and high strength to weight ratio
- EMI and RFI shielding performance is excellent
- Thermal conductivity is strong
- Electrical conductivity is strong
- Excellent surface treatment performance
- Fully recyclable
Aluminum offers obvious advantages to mechanical designers due to its strength, corrosion resistance, and heat dissipation: in addition, our patented thin-walled aluminum technology has made aluminum die-casting an option for many applications.
Applications using aluminum:
Aluminum castings improve fuel economy by reducing weight.
Aluminum is used in a variety of networking and infrastructure equipment in the telecommunications and computer industries because of the need for cooling of rf filter boxes and enclosures
In hand-held devices, the aluminum castings are EMI/RFI shielded and have good stiffness, durability, and minimal weight
Because of its excellent electrical properties and shielding properties, even at high temperatures, die-cast aluminum is ideal for electronic connectors and enclosures
What is Aluminum Die Casting
Aluminum die casting is a kind of pressure casting parts, through the casting mold pressure casting machinery die casting machine, the heat to liquid aluminum or aluminum alloy poured into the die casting machine inlet, through the die casting machine die casting, casting the mold to limit the shape and size of aluminum parts or aluminum parts, such parts are usually called aluminum die casting.
Because the metal aluminium and aluminium alloy has good liquidity and plasticity, and casting processing is in pressure die casting machine casting, aluminum die casting can make all kinds of complicated shape, can also make a higher precision and smooth finish, thus greatly reduced the mechanical processing capacity of the casting and the metal aluminum or aluminum alloy casting allowance not only saves electricity, metal materials but also greatly save the labor cost; Aluminum and aluminum alloys have excellent thermal conductivity, small specific gravity, and high work-ability;
Aluminum die casting alloys are lightweight and possess high thermal and electrical conductivity. Aluminum castings have high dimensional stability for complex part geometries and thin walls, which also withstands good corrosion resistance.
The heat dissipation of aluminum alloy and good appearance performance have exceeded most of the same use materials now, plus the weight of its own weight is the weight of other metal materials, even plastic can not be replaced.
The aluminum alloy which uses for die casting is generally ADC12 or A380. And the conductivity of die-cast aluminum alloy is about 80—-90W/M.K. The tensile strength of these materials is nearly twice that of ordinary casting alloys.
The production efficiency of die casting is relatively high, for mass production generally more than 1000 pieces a day production, and the size is stable, shrinkage rate in 0.5%.
Die-cast aluminum has more positive significance for aluminum alloy automobile wheel hub, frame and other parts that want to be produced with higher strength and impact-resistant materials.
At the same time, in lamps and lanterns and doors and windows and other products on the application is more.
Advantages of Aluminum Die casting
In die casting, the mold is filled at a pressure of 15 ~ 120MPa.The pressure is always at work during solidification.
The pressure is generated in the casting machine and is applied to the melt through the piston, and the piston slurry is injected into the mold to melt the metal.
In this way, castings with sharp edges and a wall thickness of less than 1mm can be produced. The higher casting pressure resulted in higher metal flow viscosity (10 ~ 150m/a) and shorter filling time (150 ~ 20ms).
This also means that when it comes into contact with the surface of the mold, although the cooling rate is fast, it will not solidify until the mold is filled.
For this reason, the best mold filling is very important. The high pressure acting on the surface of the mould also creates pressure that separates the two halves of the mould, and this force is the opposite of the corresponding “locking force”.
These forces put a heavy load on the mold, unlike in cold casting, which requires hot working steel and a solid mold with a stable clamp.
The hydraulic unit associated with the machine is installed with a high pressure reservoir, and controlling the machine requires extensive automation. All this doubles the cost of machinery and tools.
The high dimensional accuracy and surface properties of the production, combined with the high yield, make the process more economical, especially for long cycle processes.
These are also reasons why die casting is more widely used in aluminum alloys than other casting processes. The load on all die parts increases the pressure on the casting so that the sand core cannot be used beyond a specified temperature (higher than that in low-pressure die-casting).
The metal core must be pulled out to allow the casting to be removed from the mold, which in practice cannot be used as a groove, limiting the design of the die casting. In many cases, however, a suitable remedy can be found.
Die-casting has the following advantages;
Very high dimensional accuracy is possible with small tolerances in casting parts;
Lower mechanical tolerances and less processing are required;
Hollow cylindrical precision castings, such as bearing bodies, narrow-bore precision castings and castings with lettering;
Thin wall gradually
Clean the polished surface;
High productivity and short production time;
Aluminum Die Casting Applications
Aluminum die-casting is widely used in automobile manufacturing, internal combustion engine production, motorcycle manufacturing, motor manufacturing, oil pump manufacturing, transmission machinery manufacturing, precision instruments, landscaping, power construction, architectural decoration, and other industries.
Aluminum die casting can be made for the aluminum die casting auto parts, aluminum die casting automobile engine fittings, aluminum die casting, aluminum die casting engine cylinder of engine cylinder head, aluminum die casting valve rocker arm, aluminum die casting valve bearings, aluminum die casting power accessories, aluminum die-casting motor end cover, aluminum die casting, aluminum die casting shell pump shell, aluminum die casting building parts, aluminum die casting parts, aluminum die casting guardrail accessories, aluminum die-casting aluminum wheel, etc. Parts.
Quality Control of Aluminum Die Casting
The casting structure is characterized by its macroscopic and microscopic structure. This is the result of the transformation during solidification and subsequent cooling and heat treatment.
The micro-structure of the material and casting determines its properties. Important factors in the formation of micro-structure include chemical composition, number and distribution of crystalline cores in metals, and cooling conditions.
If these factors are changed during the casting process, the micro-structures will be correspondingly different when they are formed, resulting in different micro-structures.
The properties of cast aluminum can be said to consist of physical and chemical properties, each of which is determined according to the purpose of the casting.
Actual requirements are based on alloy standards, but for non-standard and special alloys refer to similar literature.
The data found in these documents and standards are limited to a specific range of properties and properties of alloys evaluated with specific samples, usually micro-structure.
The reason for casting property deviation may be the difference in micro-structure and casting defects, because the factors that affect micro-structure have a decisive effect on both alloy and casting properties, and defects also have an adverse effect.
These problems are solved by the standard structure of aluminum alloy castings.
The casting process records the properties of the alloys separately, taking into account the different cooling conditions that affect casting formation in sand casting, cold casting, die casting, and precision casting.
In addition, the data involved separate casting test samples and a limited range of actual castings.
This is especially true for die-casting alloys, where bulk compaction conditions strongly affect the properties of the casting.
Compared to normal dimensions and target surface roughness, casting dimensions are characterized by dimensional accuracy, machining allowance, and surface quality.
The nature of the casting process means that to some extent they will deviate from nominal dimensions, which are determined by a number of factors, such as the accuracy of the samples in sand mold castings, the accuracy of the molds in cold and die casting, and the selection of different mold materials in casting.
Other influences include the location of the mold parts and cores, the shape and size of the casting, the hardness of the mold during casting and solidification, the shrinkage characteristics of the alloy, and to some extent the hidden shrinkage of the mold and shape of the casting.
Very large castings allow for rough surfaces and surface defects to ensure high dimensional accuracy and smooth surface requirements. The difference between the size of the casting block and the corresponding smooth parts lies in the machining allowance. Their size depends on the size of the casting.
The Effect and Influence of Each Element in Die-casting Aluminum Alloy
Ⅰ. Common elements
1. Silicon (Si)
Silicon is the main element in most die-cast aluminum alloys. It can improve the casting properties of the alloy.
Silicon and aluminum can form a solid solution. At 577℃, the solubility of silicon in aluminum is 1.65%; at room temperature, it is 0.2%; and when the silicon content reaches 11.7%, silicon and aluminum form eutectic.
Although the solubility decreases with decreasing temperature, such alloys generally cannot be hardened by heat treatment. Al-Si alloys have excellent casting properties and corrosion resistance. Improve the high-temperature modeling of the alloy, reduce shrinkage, no thermal cracking tendency.
The binary aluminum base alloy has high corrosion resistance. When the content of silicon in the alloy exceeds the eutectic component, and there are more impurities such as copper and iron, the hard point of free silicon appears, which makes cutting difficult, and the melting erosion of castings crucible is serious.
If magnesium and silicon are added to aluminum at the same time to form aluminum magnesium silicon alloy, the strengthening phase is Mg Si.
The mass ratio of magnesium to silicon is 1.73:1. When designing the composition of the Al-Mg-Si alloy, the magnesium and silicon contents are proportionally arranged on the matrix.
In some Al-Mg-Si alloys, an appropriate amount of copper is added to enhance the strength and an appropriate amount of chromium is added to offset the adverse effects of copper on corrosion resistance.
The Al-Mg2-Si alloy series alloy equilibrium phase diagram shows the aluminum-rich part. The maximum solubility of Mg2Si in aluminum is 1.85%, and the deceleration is small with the decrease of temperature.
In the deformed aluminum alloy, the addition of silicon to aluminum is only limited to welding materials, and the addition of silicon to aluminum also has a certain strengthening effect.
2. Copper (Cu)
Copper and aluminum constitute a solid solution. When the temperature is 548℃, the solubility of copper in aluminum should be 5.65%.
When the temperature dropped to 302℃, the solubility of copper was 0.45%. Copper is an important alloy element, which has a certain effect on solution strengthening.
In addition, the aging precipitated CuAl2 has an obvious effect on aging strengthening. The strengthening effect is the best when the copper content is usually 2.5% – 5% and the copper content is 4% – 6.8%, so the copper content of most duralumin alloys is in this range.
Increasing the copper content can improve the fluidity, tensile strength and hardness of the alloy, but reduce the corrosion resistance and plasticity, and increase the hot crack tendency.
3. Magnesium (Mg)
Adding a small amount (about 0.2 ~ 0.3%) of magnesium to high Si-Al alloy can increase the strength and yield limit and improve the mach inability of the alloy.
Aluminum alloy containing magnesium 8% has excellent corrosion resistance, but its casting performance is poor, the strength and plasticity under high temperatures are low, and the shrinkage is large when cooling, so it is easy to produce hot crack and form loose.
In most industrial deformed aluminum alloys, the content of magnesium is less than 6%, and the content of silicon is also very low. This alloy cannot be strengthened by heat treatment equipment but has good weld-ability, corrosion resistance, and moderate strength.
The strengthening effect of magnesium on aluminum is obvious. For every 1% increase in magnesium, the tensile strength increases by about 34MPa. If the amount of manganese is less than 1%, it can be strengthened. Therefore, the addition of manganese can reduce the content of magnesium and reduce the tendency of hot cracking.
In addition, manganese can even precipitate the Mg5Al8 compound, improve corrosion resistance and welding performance.
4. Zinc (Zn)
Zinc can improve fluidity, increase hot brittleness and decrease corrosion resistance in aluminum alloy, so the content of zinc should be controlled in the prescribed range. As for ZL401 aluminum alloy with high zinc content, it has a better casting and mechanical properties and better cutting.
At 275℃, the solubility of zinc in aluminum was 31.6%, while at 125, it decreased to 5.6%. When zinc is added to aluminum alone, the increase of the strength of the aluminum alloy is very limited under the condition of deformation.
At the same time, zinc and magnesium were added to aluminum to form the strengthening phase Mg/Zn2, which had a significant strengthening effect on the alloy. When the content of Mg/Zn2 increased from 0.5% to 12%, the tensile strength and yield strength were significantly increased.
When the content of magnesium exceeds the proportion of zinc and magnesium required for forming the Mg/Zn2 phase, the stress corrosion cracking resistance is the greatest.
For example, if the copper element is added on the basis of Al-Zn-Mg to form Al-Zn-Mg-Cu series alloy, the base strengthening effect is the largest among all aluminum alloys, which is also an important aluminum alloy material in aerospace, aviation industry, and electric power industry.
5. Iron (Fe)
Harmful impurities are found in all aluminum alloys. When the iron content in the aluminum alloy is too high, the flaps or spicules of FeAl3, Fe2Al7, and Al-Si-Fe of iron exist in the alloy, which reduces the mechanical properties.
This kind of tissue will also reduce the fluidity of the alloy and increase the thermal cracking property.
However, the adhesion of aluminum alloy to the mold is very strong, especially when the iron content is less than 0.6%. When more than 0.6%, the phenomenon of adhesive mold is greatly reduced, so the iron content should be controlled in the range of 0.6 ~ 1%, which is good for die-casting, but the maximum cannot exceed 1.5%.
6. Manganese (Mn)
Manganese in aluminum alloy can reduce the harmful effects of iron, can make the aluminum alloy formed by the iron sheet or needle into a fine and dense crystalline structure, so generally allowed to have less than 0.5% of manganese in aluminum alloy.
When the manganese content is too high, it will cause segregation.
At the eutectic temperature of 658℃, the maximum solubility of manganese in solid solution is 1.82%. The strength of the alloy increases with the increase of solubility, and the elongation reaches the maximum when the manganese content is 0.8%.
Al-Mn alloy is non-aging hardening alloy, that is, it cannot be hardened by heat treatment.
Manganese can prevent the recrystallization of aluminum alloy, increase the recrystallization temperature, and refine re-crystallization grains significantly. The refining of recrystallized grains is mainly through MnAl6 compound dispersion particle to hinder the growth of recrystallized grains.
Another function of MnAl6 is to dissolve impurities of iron, forming (Fe, Mn) Al6, reducing the harmful effects of iron.
Manganese is an important element of aluminum alloy, which can be added alone to form Al-Mn binary alloy, and more with other alloying elements, so most aluminum alloys contain manganese.
7. Nickel (Ni)
Nickel in aluminum alloy can improve the strength and hardness of the alloy, reduce the corrosion resistance. The effect of nickel and iron is the same, can reduce the melting corrosion of the alloy to the mold, at the same time can neutralize the harmful effect of iron, improve the welding performance of the alloy.
When the nickel content is 1 ~ 1.5%, the casting can be polished to obtain a smooth surface. Due to the lack of nickel sources, aluminum alloys containing nickel should be used as little as possible.
8. Titanium (Ti)
Adding trace titanium to aluminum alloy can significantly refine the grain structure of aluminum alloy, improve the mechanical properties of the alloy, and reduce the hot crack tendency of the alloy.
Ⅱ. minor element
Iron and Silicon
Iron in Al-Cu-Mg-Ni-Fe wrought aluminum alloy, silicon in Al-Mg-Si wrought aluminum, and in Al-Si welding rod and Al-Si casting alloy, are all added as alloy elements.
In base aluminum alloy, silicon and iron are common impurity elements, which have a significant influence on alloy properties. They exist mainly as FeCl3 and free silicon. When silicon is larger than iron, the β-FeSiAl3 (or Fe2Si2Al9) phase is formed, and when iron is larger than silicon, the α-Fe2SiAl8 (or Fe3Si2Al12) phase is formed.
When the ratio of iron to silicon is not appropriate, it will cause the casting to crack, and the high iron content in the cast aluminum will make the casting brittle.
Titanium and Boron
Titanium is a common additive element in aluminum alloys, which is added in the form of Al-Ti or Al-Ti-B intermediate alloys.
Titanium and aluminum form TiAl2 phase, which becomes the non-spontaneous core during crystallization, and plays the role of refining cast structure and weld structure.
For the inclusion reaction of Al-Ti alloys, the critical content of titanium is about 0.15%, and the reduction is as low as 0.01% if boron is present.
Chromium is a common additive element in Al-Mg-Si, Al-Mg-Zn and Al-Mg alloys. At 600℃, the solubility of chromium in aluminum is 0.8%, basically insoluble at room temperature.
Chromium forms intermetallic compounds in aluminum, such as (Cr-Fe) Al7 and (Cr-Mn) Al12, which block the nucleation and growth of re-crystallization, strengthen the alloy, improve its toughness and reduce the sensitivity of stress corrosion cracking.
But the meeting place increases the quenching sensitivity, causes the anodic oxidation film to show the yellow.
The addition of chromium to aluminum alloys is generally not more than 0.35% and decreases with the increase of transition elements in the alloys.
Strontium is a surface-active element, which can change the behavior of the intermetallic compound phase in crystallography.
Therefore, the modification with the strontium element can improve the plasticity and final product quality of the alloy.
Strontium has the advantages of long metamorphism effective time, good effect and reproducibility.
Adding 0.015%~0.03% strontium to the extruded aluminum alloy can change the β-AlFeSi phase in the ingot into the α-AlFeSi phase, reduce the ingot homogenization time by 60%~70%, and improve the mechanical properties and plastic work-ability of the material. Improve product surface roughness.
For the deformation of high silicon (10% ~ 13%), adding 0.02% ~ 0.07% strontium aluminium alloy elements can make the crystal to reduce to a minimum, at the beginning of mechanical properties was also significantly increased, tensile strength б b from 233 MPa to 236 MPa, yield strength 60.2 from 204 MPa to 210 MPa, elongation 65 increased from 9% to 12%.
Adding strontium to the super-eutectic Al-Si alloy can reduce the size of primary silicon particles and improve the plasticity of the alloy.
Zirconium is also a common additive to aluminum alloys. Generally, the addition of 0.1%~0.3% in aluminum alloy results in ZrAl3 compound formed by zirconium and aluminum, which can hinder the re-crystallization process and refine re-crystallization grains.
Zirconium also refines the cast structure but is less effective than titanium.T he presence of zirconium reduces the effect of titanium and boron on grain refinement. In Al-Zn-Mg-Cu series alloys, zirconium should be used instead of chromium and manganese to refine re-crystallization because zirconium has less effect on quenching sensitivity than chromium and manganese.
Ⅲ. The impurity elements
The addition of rare-earth elements into aluminum alloy increases the super-cooling of components, refines the grains, reduces the secondary crystal spacing, reduces the gas and inclusions in the alloy, and makes the inclusions tend to spherification.
It can also reduce the surface tension of melt and increase the fluidity, which is conducive to pouring into ingot and has a significant influence on the process performance.
The addition amount of various rare-earth is about 0.1%. The addition of mixed rare earth (La-Ce-Pr-Nd, etc.) reduced the critical temperature formed in the aging GP region of Al-0.65% mg-0.61% Si alloy. Aluminum alloy containing magnesium can stimulate the metamorphism of rare earth elements.
Influence of impurity elements
Vanadium forms VAl11 refractory compound in aluminum alloy, which plays a role in refining grains during the melting process, but less than that of titanium and zirconium. Vanadium can also refine re-crystallization structure and increase re-crystallization temperature.
The solid solubility of calcium in aluminum alloy is very low, forming CaAl4 compound with aluminum, calcium is the super-plastic element of aluminum alloy, about 5% calcium and 5% manganese aluminum alloy has super-plastic.
Calcium and silicon form Ca-Si, which is insoluble in aluminum and can slightly improve the conductivity of industrial pure aluminum by reducing the amount of solid solution of silicon.
Calcium can improve the cutting performance of aluminum alloy. CaSi2 does not heat – strengthen aluminum alloys. Trace calcium helps remove hydrogen from the aluminum solution.
Lead, tin, and bismuth are low melting point metals, their solid solubility in aluminum is not large, slightly reduce the strength of the alloy. The expansion of bismuth during solidification is beneficial to complement shrinkage. The addition of bismuth to high magnesium alloys can prevent sodium brittleness.
Antimony is mainly used as a metamorphic agent in cast aluminum alloys. Bismuth is only substituted for sodium brittleness in Al-mg deform-able aluminum alloys. Antimony was added to some Al-Zn-Mg-Cu alloys to improve the properties of hot and cold pressing processes.
The structure of oxide film can be improved and the burning loss and inclusion can be reduced. Beryllium is a toxic element that can cause allergic poisoning. Therefore, aluminum alloys that come into contact with food and beverages cannot contain beryllium.
The beryllium content in welding materials is usually controlled below 8 g/mL. The content of beryllium should also be controlled in aluminum alloys used as welding substrates.
Almost don’t dissolve in sodium in aluminum solid solubility is less than 0.0025%, the largest of the low melting point of sodium (97.8 ℃), sodium exist in the alloy, adsorption on the surface of the dendrite in the process of solidification or grain boundary, hot working, sodium form liquid adsorption layer on the grain boundary, produce brittle cracking, Na-Al-Si compound formation, no free sodium exists does not produce sodium “fragile”.
When the content of magnesium exceeds 2%, magnesium grabs the silicon, precipitates free sodium, produces “sodium brittleness”. Therefore, high magnesium-aluminum alloy is not allowed to use sodium salt flux.
The methods to prevent “sodium brittleness” include chlorination, which causes sodium to form NaCl and discharge into the slag, and bismuth to generate Na2Bi and enter into the metal matrix. Antimony to form Na3Sb or the addition of rare earth can also play a similar role.