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Dongguan City - Casting Metal Products Co., Ltd
Address: Liao Bu Town, Dongguan City, Guangdong Province, Tong Lip Village Street
Integrity - enterprise:zch13825787603

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Casting the reasons for the occurrence of dark spots:

There are several reasons for this. There may be silicon oxide, or alumina formation. The solution is very simple, the use of fresh aluminum ingots. However, the greatest possibility is derived from the release agent. It may be that we spray too much release agent. It is also possible that the organic content of the release agent is too high. These organics at the temperature of hot-melt aluminum, some were reduced to carbon, and some become organic macromolecular polymers. The mixing of these carbon molecules and polymer, when the aluminum casting is formed, is contained in the surface layer, as we see the dark spots. We can reduce the concentration of the spray, use another spray, or lengthen the time after the spray. To reduce the formation of carbon, and anti-macromolecular polymer accumulation. Another common practice is.
Magnesium alloy characteristics:
Light weight - the proportion of magnesium alloys in all structural alloys are light,
Its specific gravity is aluminum alloy
, & Lt;
Zinc alloy
, Iron and steel
twenty three%
, Which it does
The product of the shell, the internal structure of pieces, or cars, aircraft and other parts
Excellent material
1. Light weight - the proportion of magnesium alloys in all structural alloys are light, and its proportion for the 68% aluminum alloy, zinc alloy, 27%, 23% of steel, which do 3C products in addition to the shell, the internal structure Pieces, or automotive, aircraft and other parts of the excellent material
 2. Specific strength and specific rigidity - The specific strength of magnesium alloy is obviously higher than that of aluminum alloy and steel, which is equal to that of aluminum alloy and steel, which is ten times higher than that of engineering plastics.
 3. Good resistance to vibration - under the same load, shock absorption is 100 times that of aluminum, titanium alloy of 300 to 500 times
4. Electromagnetic shielding good - 3C products shell (mobile phones and computers) to provide superior anti-electromagnetic protection, and magnesium alloy shell can completely absorb the frequency of more than 100db of electromagnetic interference
 5. Good heat dissipation - general metal thermal conductivity is hundreds of times the plastic, magnesium alloy thermal conductivity slightly lower than aluminum and copper alloy, much higher than the titanium alloy, the specific heat is close to the water, is commonly used in alloys The highest
6. Good texture - the appearance of magnesium alloy and excellent texture touch, so that the product is more luxurious
7. Recyclability is good - as long as the cost of new material equivalent to the price of 4%, can be magnesium alloy products and waste recycling
8. Stable supply of resources - magnesium reserves in the earth's crust in eighth place, most of the magnesium raw materials extracted from the sea, so its resources stable and adequate
Aluminum alloy die casting characteristics and definition:
Aluminum die casting is a pressure casting parts, is the use of casting casting mold casting pressure casting machine, the heating of liquid aluminum or aluminum pouring into the die-casting machine inlet, the die-casting machine casting, casting out Molds are limited in size and shape to aluminum or aluminum parts, and such parts are often referred to as aluminum alloy die castings. Aluminum die casting in different places also have different names, such as die-casting aluminum parts, die-cast aluminum, die-casting aluminum, aluminum die casting, aluminum die-casting parts, aluminum die-casting parts. As the aluminum alloy and metal aluminum has good plasticity and mobility, and casting process is in the pressure casting machine casting, so aluminum alloy die casting can make a variety of more complex shapes, but also to make higher Smoothness and precision, thus greatly reducing the mechanical processing of castings and aluminum or aluminum alloy casting surplus, not only saves electricity, metal materials, but also greatly saves labor costs; and aluminum and aluminum alloy has excellent Aluminum alloy die castings are widely used in internal combustion engine production, automobile manufacturing, motorcycle manufacturing, motor manufacturing, power construction, pump manufacturing, precision instruments, landscaping, transmission machinery Manufacturing, architectural decoration, and other industries. Aluminum die castings can be manufactured for aluminum die-cast automotive parts, aluminum die-cast automotive engine tubes, aluminum die-cast pump housings, aluminum die-cast gasoline engine cylinder heads, aluminum die-cast engine cylinders, aluminum die-cast valve bearings, aluminum die-cast valve rockers, aluminum Aluminum die-casting construction accessories, aluminum die-casting motor cover, aluminum die-casting fence accessories, aluminum die-casting decorative accessories, aluminum die-casting aluminum wheels, and so on.
The advantages and disadvantages of die-casting manufacturing: die-casting is a use of high pressure to force the metal melt into the shape of a complex metal mold casting method. In 1964, the Japan Die Casting Association for the die-casting is defined as "high temperature will melt alloy into the precision molds, in a short time mass production of high precision casting surface and good casting." Die Casting said the United Kingdom, the United Kingdom said die-casting For the Pressure Die Casting, the most familiar with the general domestic industry is Japan's argument, known as die-casting. Castings produced by die casting are referred to as die castings.

The tensile strength of these materials, nearly twice as high than the average cast alloy, aluminum alloy wheels, frames and other materials with the hope that the use of higher strength impact resistant parts of production, a more positive significance.

Advantages of die casting include excellent dimensional accuracy of the castings. Usually this depends on the casting material. Typical values ​​are 0.1 mm for the initial 2.5 cm size and 0.002 mm for every 1 cm increase. Compared to other casting process, its cast surface is smooth, fillet radius of about 1-2.5 microns. Castings with a wall thickness of about 0.75 mm can be made with respect to the sandbox or the permanent mold casting method. It can be cast directly to the internal structure, such as silk sets, heating elements, high-strength bearing surface. Other advantages include the ability to reduce or avoid secondary machining, high production speeds, casting tensile strength of up to 415 MPa, and the ability to cast high-flow metals.

Die casting the biggest drawback is the high cost. Casting equipment and molds, mold-related components relative to other casting methods are very expensive. So the production of a large number of die casting products only more economic. Other shortcomings include: This process is only applicable to high mobility of the metal, and casting quality must be between 30 grams and 10 kg. [5] In the usual die-casting, the final casting of a group of castings always have pores. So that any heat treatment or welding can not be carried out because the gas in the gap will expand under the action of heat, resulting in internal micro-defects and surface peeling.


Cracking tendency and stress generation of aluminum alloys:
    Alloy in the solidification shrinkage process, subject to external resistance is too large, easy to crack. Al-Si and Al-Mg alloys are prone to crack.

    Cracks are hot and cold crack split, observe the cracks, irregular and irregular shape, the surface is strongly oxidized, dull heat cracking, the first was cold crack.

    Hot cracking is the alloy produced during the solidification process, that is, most of the alloy has been formed dendritic framework began to solidify, but there are still a small amount of liquid dendritic pieces, the maximum contraction of the alloy at this time, the thermal strength of the alloy is very low, such as The mold hinders its contraction, produces the systolic pressure, when its strain quantity is bigger than the alloy in this temperature the alloy strength allowed strain quantity, namely produces the crack.

    Cold cracking is a serious contraction in the solid alloy is affected by external forces or, such as the early sand or cleaning up the process of mechanical damage resulting in cold cracking. Cold cracking rarely occurs.

    Casting in the mold in the cooling process of freezing will produce stress deformation, the stress in the range of elastic strength, residual stress will exist in the casting to reduce casting design strength, castings in use and processing of deformation, casting precision and assembly .

    Casting stress by the thermal stress, phase transformation stress and shrinkage stress in three parts. Die casting stress can be annealed by natural failure to eliminate the goods.

Five shortcomings of aluminum alloy die casting defects
Cold. Split. Reduction. Gas. Aluminum die casting is the five shortcomings referred to:
A: cold: refers to the casting surface rough rough uneven cold pattern dissatisfaction with water and so on.
2: crack: refers to the sticky mold crack. Top crack. Mold temperature is too low cold cracking.
Three: shrinkage: refers to the cast surface uneven with depression.
4: gas: refers to the casting feed bit has holes. Overflow bag bag mouth has holes. Casting surface bubbles. Casting internal stomata.
Five: off: refers to the surface layer of castings as thin as the purple off we call him peeling off. Thin and thin and there are a lot of small and some side of the thin off the other side and the castings adult body we called him.
Said above is all the defects of die-casting problems, the former counterparts cast defects to say 100 kinds of castings, most of the casting defects that we do not understand the name heard of people who have read a few years, said the book casting defects Name with the physical, the history of Chinese die-casting thousands of years, how to put the casting defects so complex now, you say you, I said I, then I want to cast defective name can not be unified communication, through my actual Work experience in 2005 to write five shortcomings of casting short: cold: crack: shrink: gas: off.
The lifting of the five major shortcomings: one: to understand the casting process to find the correct feed orientation. 2: Understanding the weight of the product. How much of the sprue needs to be positioned. Three: to understand the product structure. How to use the runner. Runner is the leading flow channel. Four: to understand the product structure. To open the gate. An import. Two import. Multi-channel imports. Point of imports, as long as you understand the casting from these areas can solve the five major defects.
Casting several major defects has been the difficulty of die-casting company .. First, how stagnant stoma will stay inside. Second, art flow slag bag mouth of the pores caused by what problems. Casting surface size of the bubble is how come. Casting stomata why it is difficult to lift. Fifth, the main process of castings produced skins where wrong. 6. Casting Why peeling - root mold release agent have relations. Seven or six words at the beginning of the aluminum why it is difficult to do, the idea of ​​what the details. 8. Zinc alloy castings after the surface of the bubble, is the material problem or mold (machine. Modulation) problems, or electroplating factory problem, how can we determine the material problem - or die-casting process problems - or die - or plating problem. 9. How to do zinc alloy casting surface strength. 10. What kind of release agent for copper castings is best.
Die-casting technology: die-casting company is the basis for survival, a good technology to reflect the company's ability.
Die casting management: the development of the direction of die-casting company, die-casting company's best management is to do control (control costs. Control quality. Good production.), Is to let all managers. Employees in accordance with the management system developed by the company to do .

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We need to pay attention to those in the aluminum die-casting?

Aluminum alloy die-casting products are mainly used in electronics, automobiles, motors and some communications industries, of course, the main purpose or in some parts of the apparatus, we need to pay attention to those in the aluminum die-casting?

1, consider the issue of stripping,

2, consider the problem of aluminum alloy die-casting wall thickness, the gap between the thickness of the General Assembly to bring about the impact of filling

3, try to avoid the structure of the mold structure to avoid the complex structure of the emergence, had to use a number of core pulling or spiral core pulling

4, some die casting appearance may have special requirements, such as fuel injection

5, the design taking into account the mold, if there are multiple locations of the core position, try to put both sides, it is best not to place the next core pulling, so a long time under the aluminum alloy die-casting core problems.




What factors easily lead to burst the consequences of mold

1. Mold material is not good in the subsequent processing of easy to break

2. Heat treatment: quenching and tempering process improper deformation

3. Mold grinding flatness is not enough, resulting in flexural deformation

4. Design process: mold strength is not enough, knife too close spacing, mold structure is unreasonable, the number of templates is not enough pad-free pad feet

5. Wire cut improper handling: cable cut line, the gap does not, did not make clear angle

6. Punching equipment selection: punch tonnage, punching force is not enough, transfer mode too deep

7. Material removal is not smooth: no demagnetization treatment before production, no material back shoot; production broken broken spring and other card materials

8. Blanking is not smooth: when the assembly module without leakage of feces, or roll blocking feces, pad feet blocking feces


9. Production awareness: laminated stamping, positioning is not in place, did not use the blow | gun, the template is still crack production

Dongguan City - Casting Metal Products Co., Ltd
Address: Liao Bu Town, Dongguan City, Guangdong Province, Tong Lip Village Street
Integrity - enterprise:zch13825787603