Research on shrinkage cavities in aluminum die castings and strategies to reduce the scrap rate from 5% to 0.2% was conducted. Shrinkage cavities, common internal defects in aluminum alloy die-casting parts, often occur in areas with large wall thickness or hot spots. While generally acceptable if they don’t impact product performance, certain critical parts, such as cooling water or lubricating oil passages in automobile engine cylinder blocks, must be free of shrinkage holes.

Shrinkage cavities are common internal defects in aluminum alloy die-casting parts. They often appear in locations where the wall thickness of the product is relatively large or where hot spots are prone to form. Generally speaking, as long as shrinkage cavities do not affect the performance of the product, they will be judged as qualified. However, for some important parts, such as the cooling water passage holes or lubricating oil passage holes of the automobile engine cylinder block, the occurrence of shrinkage holes is not allowed to be judged as qualified.

An aluminum alloy engine crankcase from a certain company is cast using a Bühler 28 000 kN cold chamber die-casting machine and is made of ADC12 alloy. The mass of the casting blank is 6.3 kg. During the X-ray inspection in the post-process, it was found that shrinkage holes appeared in the oil passage of the second crankshaft bearing hole, which was about 8 mm away from the oil passage, and there was a large risk of oil leakage. According to statistics, the scrap rate of shrinkage cavities at this location in 2017 was 5%. After a series of explorations, the scrap rate was successfully reduced to 0.2%.

Mechanism and morphology of shrinkage cavities in aluminum alloy die castings

Shrinkage cavity formation mechanism

There are many reasons for shrinkage cavities in aluminum alloy die castings. Tracing back to its origin, it is mainly caused by insufficient feeding of the aluminum liquid during the transition from the liquid phase to the solid phase of the aluminum alloy. Common causes of shrinkage include:

• The mold temperature gradient is unreasonable, resulting in inconsistent local shrinkage of aluminum liquid.
• The pouring amount of aluminum liquid is too small, resulting in a thin material cake and insufficient pressure compensation during the boosting stage.
• The mold has hot knots or sharp areas.
• The inner gate of the mold is not wide enough and has a small area, which causes the casting to solidify prematurely, hinders pressure transmission during the pressurization stage, and prevents the aluminum liquid from being fed.
• If the casting pressure is set too low, the feeding effect will be poor.

Casting shrinkage cavity morphology

Shrinkage cavities are a common internal defect in aluminum alloy die-casting parts and even castings. They often appear in areas with large wall thickness, sharp corners of the mold, and large mold temperature differences. Figure 2 shows the shape of the shrinkage hole in the crankcase of a certain engine. The shrinkage hole is oval-shaped, about 10 mm from the bearing oil passage hole, and the inner wall is rough and dull. The wall thickness of the casting in the shrinkage cavity area is relatively large, about 22 mm; there is no cooling water at the front end of the oil passage hole pin, and the mold temperature is relatively high. The two major journals of the automobile engine crankshaft (main journal and connecting rod journal) have a large working load and serious wear, so pressure lubrication must be carried out during operation. In this case, if there are shrinkage holes near the oil passage hole of the journal, it will seriously affect the lubrication effect.

Measures related to shrinkage cavities

The reasons for casting defects in aluminum alloy die-casting parts include the structural characteristics of the product itself, unreasonable mold design, unreasonable design of the gating system and cooling system, and unreasonable design of process parameters. Based on the common causes of casting defects and the processing procedures for aluminum alloy casting defects, we explore corresponding countermeasures to solve shrinkage cavities in thick and large parts of aluminum alloy die castings.

Early analysis and countermeasures

The preliminary analysis of shrinkage cavities in castings starts with easy-to-operate process parameters. Through on-site measurement and observation, the measured inner gate thickness of the mold is 4 mm, the calculated inner gate speed is 40 m/s, and the thinnest part of the product wall thickness is 4.6 mm; material cake thickness is 25 mm; casting pressure is 60 MPa. It is known from experience that if the mold design conforms to the structural characteristics of the product, the mold gating system should not have the problem of insufficient feeding during the pressurization stage. However, the aluminum liquid feeding in the pressurization stage is directly related to the material cake thickness and the pressurization pressure. Only suitable material cake thickness and casting pressure can form castings with dense internal structures. Therefore, it can be suspected that shrinkage cavities are caused by casting pressure deviation. Caused by low and thin dough.

There are two early strategies to eliminate shrinkage cavities in castings:

1. The casting pressure was increased from the previous 65MPa to 90 MPa.
2. The thickness of the cake is adjusted from the original 25 mm to 30 mm. After adopting the above measures, the shrinkage rate was reduced from 5% to 4.8% after small-batch special flow verification. The effect was not obvious, indicating that process parameters are not the main cause of shrinkage in castings.

Interim Analysis and Countermeasures

Since the essential cause of shrinkage cavities in castings is insufficient feeding during the solidification of molten aluminum, uneven temperature distribution in the mold can easily lead to unreasonable solidification sequence of molten aluminum, resulting in insufficient feeding. Therefore, the mid-term countermeasure analysis mainly focuses on ensuring a reasonable mold. Begin with the temperature. It can be seen from the product 3D model that the wall thickness of the shrinkage cavity of the casting is 22.6mm. The larger wall thickness can easily cause a higher mold temperature. When the aluminum liquid solidifies, the aluminum liquid inside the casting with a large wall thickness is still in the liquid phase or the solid-liquid mixed phase due to the high temperature, and at this time, the feeding channel of the inner gate may have solidified. In this way, the casting cannot be fed with molten aluminum during the pressurization stage, which may lead to the formation of shrinkage cavities. In order to ensure the appropriate mold temperature, a thermal imager was used to measure the maximum mold temperature after spraying the release agent to be 272°C, which is higher than the normal mold temperature after spraying. The mold temperature and distribution in other areas are generally normal. Therefore, it is necessary to reduce the mold temperature in the shrinkage cavity. In addition, it is measured that the distance between the bottom of the cooling water hole and the surface of the mold cavity is 20 mm. Because a larger heat transfer distance will reduce the cooling effect of the mold, the cooling water hole needs to be changed.

In order to reduce the temperature of the mold at the shrinkage cavity, three main methods are adopted:

1. Improve the mold cooling system. Deepen the depth of the cooling water hole of the shrinkage cavity attachment from 20 mm to 12 mm from the mold surface, so as to quickly take away the heat of the nearby mold and reduce the mold temperature; number all the mold cooling water pipes and water pipes in a unified manner, corresponding one to one to prevent There is a mistake in mold preservation, which affects the cooling effect.
2. Lower the pouring temperature from 675 °C to 645 °C.
3. Extend the spraying time of the mold at the shrinkage cavity from 2 s to 3 s. After the above rectification measures were implemented, the temperature of the mold in the shrinkage cavity area dropped significantly after spraying, to about 200°C, which was within the normal range. The shrinkage rate was reduced from 4.8% to 4%, indicating that such measures have a certain effect on shrinkage, but they cannot completely solve the shrinkage problem in this area.

Later analysis and countermeasures

Through the previous two improvements, it is basically guaranteed that the die-casting mold is in a theoretically reasonable state; that is, the pouring system is reasonably designed, the cooling system is properly arranged, and the process parameter design is optimal. However, the shrinkage rate of castings is still as much as 4%. The wall thickness of the casting shrinkage cavity is 22.6 mm, which is much larger than the wall thickness of other parts. The larger wall thickness may cause insufficient feeding during solidification in the center of the casting. After the pressurization is completed, this area has not yet completely solidified and continues to shrink to produce shrinkage cavities. Therefore, how to solve the problem of insufficient feeding in the shrinkage cavity of castings may be the key to the problem. Generally speaking, the feeding of castings is carried out through the path of cake → sprue → ingate → casting. Since the thick part of the casting solidifies at the inner gate, the feeding channel in the later stage of pressurization is cut off, so feeding cannot be done.

In view of the conventional pressurization stage, the injection punch applies casting pressure through the material cake to achieve the feeding effect. The measure taken is to add a slag bag-like structure near the shrinkage hole of the casting to act as the material cake and use a pair of oil cylinder core-pulling mechanisms to act as punching First, in the late solidification stage of the casting, secondary pressurization and feeding are performed on the areas prone to shrinkage cavities to achieve the purpose of eliminating shrinkage cavities. Generally speaking, such a secondary pressurization mechanism is called an extrusion pin. Its pressurization principle is to apply appropriate pressure after the molten metal or alloy liquid is poured and before it is completely solidified to enhance the solidification and feeding effect of the casting and improve the casting quality. Density: reduce or eliminate shrinkage cavities. Pressurized solidification can change the physical parameters and crystallization process of metals and their alloys, change the distribution and size of loose voids, increase the density of castings, and improve the tensile strength, hardness, and other properties of castings.

According to the law of casting feeding and pressurization, the extrusion pin action signal adopts the pressurization signal of the casting process and is delayed as the start signal on this basis. Therefore, the extrusion pin mainly controls the two parameters of extrusion depth and extrusion delay time. . The extrusion depth depends on the casting structure and the distribution and size of shrinkage holes, generally 10~20 mm; the extrusion delay mainly refers to the pressurization time setting, usually 2~5 s. In actual engineering, the determination of extrusion parameters is based on empirical values and then optimized according to the casting situation. In order to easily adjust the extrusion parameters, a separate oil cylinder is usually used to control the extrusion pin action.

For crankcase castings, the later improvement measures were to arrange two extrusion pins symmetrically near the mold bearing holes, and optimize the secondary pressurization of the extrusion pins by adjusting the two main parameters of extrusion depth and extrusion delay. The effect is to reduce the shrinkage porosity of castings. On the basis of the aforementioned measures, after two additional extrusion pins were added to the mold, the shrinkage rate dropped significantly, and the defective rate dropped from 4% to 0.2%. At the same time, among the defective products with 0.2% shrinkage cavities, the size of the shrinkage cavities is significantly reduced. Therefore, the extrusion pin solution plays a better role in controlling the shrinkage rate of castings with increased wall thickness. However, during this improvement process, the shrinkage cavity defect rate of castings also experienced fluctuations. By optimizing the extrusion parameters—the extrusion depth is 15 mm, the extrusion delay time is 2.5 s, and the specified extrusion pin service life (times/8000 molds) and other relevant specifications—the casting defect rate has been stabilized at around 0.2%.

X-ray flaw detection
Comparative photos of X-ray flaw detection before and after improvement of the shrinkage cavity area of the casting It can be seen that shrinkage holes in the castings appear near the bearing holes, are widely distributed and scattered, and the structure is relatively loose. Since the bearing holes in the cylinder block need to be filled with pressure-lubricating oil, there is a risk of oil leakage in the castings during use. After improvement, from The loose distribution of shrinkage cavities can no longer be seen in the X-ray inspection photos, and the internal structure of the casting appears denser.

in conclusion

• Shrinkage cavities are a common internal defect of castings and tend to appear in areas with a larger wall thickness and a higher mold temperature. Usually starting from several aspects such as mold design (pouring system, cooling system), process parameter setting, and casting condition guarantee For the castings with larger wall thicknesses involved, traditional improvement measures can only alleviate the problem but cannot completely solve it.
• Two extrusion pins are designed to imitate the feeding effect of the punch during the pressurization stage, which plays a secondary pressurizing and tightening effect on the shrinkage hole area, and the effect is obvious.

The post Research on shrinkage cavities in aluminum die castings first appeared on MindWell.

One of our company’s engine crankcases made of aluminum alloy is cast in Bühler’s 28 000kN cold chamber die casting machine, made of ADC12 alloy. The gross mass of the casting was 6.3 kg, and when X-ray flaw detection was carried out in the post-process, it was found that there was a shrinkage hole in the oil passage of the second crankshaft bearing hole, which was about 8 mm away from the oil passage, and there was a large risk of oil leakage. According to statistics, the scrapping rate of shrinkage holes in this position was 5% in 2017, and after a series of exploration, the scrapping rate was successfully reduced to 0.2%.

Aluminum alloy die casting shrinkage hole formation mechanism and morphology

Shrinkage formation mechanism

Lead to aluminum alloy die casting shrinkage of more reasons, trace its origin, mainly from the liquid phase of aluminum alloy to the solid phase transition process of aluminum liquid shrinkage caused by insufficient. Common reasons for shrinkage are:
① Mold temperature gradient is unreasonable, resulting in inconsistent local contraction of liquid aluminum.
② liquid aluminum pouring volume is small, resulting in thin cake, insufficient pressurization stage of pressurization.
③There are hot knots or sharp areas in the mold.
④ The inner gate of the mold is not wide enough and the area is small, which leads to premature solidification of the casting, and the pressure transfer is blocked in the boosting stage, and the aluminum liquid cannot make up the shrinkage.
⑤ The casting pressure is set too low, and the effect of shrinkage is poor.

Shrinkage hole pattern of casting

Shrinkage hole is a kind of aluminum alloy die casting and even casting common internal defects, often appear in the product wall thickness is large, mold sharp corners and mold temperature temperature difference is large and other areas. Figure 2 for a certain engine crankcase shrinkage hole pattern, shrinkage hole is like an ellipse, about 10 mm from the bearing oil hole, the inner wall is rough, no luster. Shrinkage hole area casting wall thickness is larger, about 22 mm; oilway hole pin front without cooling water, mold temperature is higher. The two main journals of the crankshaft of the automobile engine (main journal and connecting rod journal) have a large working load and serious wear, and must be pressure lubricated during work. In this case, the presence of shrinkage holes near the oilway holes of the journals will seriously affect the lubrication effect.

Shrinkage hole related countermeasures

Aluminum alloy die casting casting defects are caused by the product’s own structural characteristics, mold design pouring system and cooling system design is unreasonable, process parameters are not designed reason. According to the common reasons for casting defects and aluminum alloy casting defects treatment process, to explore the solution of aluminum alloy die casting thick parts of shrinkage hole corresponding countermeasures.

Pre-analysis and countermeasures

Pre-analysis of casting shrinkage from the easy to operate process parameters, through on-site measurement and observation, measured the mold gate thickness of 4 mm, the calculated inner gate speed of 40 m/s, the product wall thickness of the thinnest place for the 4.6 mm; cake thickness of 25 mm; casting pressure of 60 MPa. From experience, mold design in line with the structural characteristics of the product, the mold casting system should not have a pressurization stage to make up the shrinkage of insufficient problems. However, the aluminum liquid in the pressurization stage is not enough to make up the shrinkage. However, the shrinkage of aluminum liquid in the boosting stage is directly related to the thickness of the cake and the boosting pressure, and the appropriate thickness of the cake and the casting pressure can form the casting with dense internal organization. Therefore, it can be suspected that the shrinkage holes are caused by the casting pressure is low and the cake is thin.

The countermeasures to eliminate shrinkage in castings in the first stage are divided into two:

• Increase the casting pressure from 65MPa to 90MPa;
• The thickness of the cake is adjusted from 25 mm to 30 mm. After the adoption of the above measures, the shrinkage rate is reduced from 5% to 4.8% after the verification of small batch special flow, the effect is not obvious, which indicates that the process parameters are not the main cause of shrinkage of the castings.

Mid-term analysis and countermeasures

Since the essential cause of casting shrinkage is the insufficient shrinkage of aluminum solidification, and the uneven distribution of mold temperature can easily lead to the unreasonable order of aluminum solidification, thus insufficient shrinkage, therefore, the medium-term countermeasures analysis mainly starts from ensuring a reasonable mold temperature. From the 3D model of the product, it can be seen that the wall thickness at the shrinkage hole of the casting is 22.6mm, and the wall thickness is larger, which is easy to cause a higher mold temperature. When the aluminum liquid solidifies, the aluminum liquid inside the casting with large wall thickness is still in the liquid phase or solid-liquid mixed phase due to the high temperature, while the channel for making up the shrinkage in the inner gate may have already solidified at this time. As a result, the casting is not able to make up for the aluminum liquid during the pressurization phase, which may lead to the formation of shrinkage holes. In order to ensure the appropriate mold temperature, the thermal imaging camera was used to measure the maximum temperature of the mold after the mold release agent spraying was 272 ℃, which was higher than the normal temperature of the mold after spraying, and the temperature of the mold and its distribution was normal in other areas. Therefore, it is necessary to reduce the mold temperature at the shrinkage hole. In addition, it was measured that the distance between the bottom of the cooling water hole and the surface of the mold cavity is 20 mm, because a larger heat transfer distance will reduce the cooling effect of the mold, so the cooling water hole needs to be changed.

In order to reduce the temperature of the mold at the shrinkage hole, three main methods are adopted:

• Improve the mold cooling system. Shrinkage holes attached to the depth of the cooling water hole deepened from the mold surface 20 mm into 12 mm, in order to quickly take away the heat of the mold near the mold, reduce the mold temperature; all the mold cooling water pipe and the water pipe unified number, one by one correspondence, to prevent the mold preservation of the wrong fashion, affecting the cooling effect.
• Reduce the pouring temperature, from 675 ℃ to 645 ℃.
• extend the shrinkage hole at the mold spraying time, from 2 s into 3 s. After the implementation of the above corrective measures, shrinkage hole area mold spraying temperature is greatly reduced, about 200 ℃, belongs to the normal range. Shrinkage rate of 4.8% to 4%, indicating that such measures have a certain effect on shrinkage, but can not completely solve the problem of shrinkage in this area!

Post-analysis and countermeasures

Through the previous two improvements, basically ensure that the die-casting mold is in a theoretically reasonable state, that is, the pouring system design is reasonable, the cooling system arrangement is appropriate, and the process parameters are designed optimally. However, the rate of casting shrinkage is still as much as 4%. Castings shrinkage hole at the wall thickness of 22.6 mm, much larger than other parts of the wall thickness, a larger wall thickness may cause the casting center solidification of complementary shrinkage is insufficient, after the end of the pressurization of the region has not been completely solidified, and continue to contraction of shrinkage holes. Therefore, how to solve the casting shrinkage holes in the shrinkage of the complementary shrinkage, may be the key to the problem. Generally speaking, the casting shrinkage through the cake → sprue → gate → casting path. Due to the casting of thick parts after the solidification of the inner gate, cut off the pressurization of the late make-up shrinkage channel, so can not make up for the shrinkage.

In view of the conventional pressurization stage of the injection punch through the cake to exert casting pressure to achieve the role of shrinkage, the measures taken are in the casting shrinkage hole near the increase of a similar slag packet structure to act as a cake, the use of a pair of cylinders pumping mechanism as a punch, in the casting solidification late in the region prone to shrinkage holes in the second pressurization shrinkage to eliminate the shrinkage hole purpose. Generally speaking, this secondary pressurization mechanism is called extrusion pin, it is the principle of pressurization in the metal or alloy liquid pouring to completely solidify before applying appropriate pressure to strengthen the casting solidification shrinkage effect, to improve the casting density, reduce or eliminate the purpose of shrinkage holes. Pressurized solidification can change the metal and its alloy physical parameters and crystallization process, change the distribution and size of the loose cavity, improve the casting density, improve the casting tensile strength and hardness and other properties.

According to the casting shrinkage, pressurization law, extrusion pin action signal using the casting process of the pressurization signal, and based on the delay as the start signal, therefore, the extrusion pin is mainly to control the extrusion depth and extrusion delay time two parameters. Extrusion depth according to the casting structure and shrinkage hole distribution, size, generally 10 ~ 20 mm; extrusion delay time is mainly set with reference to the pressurization time, generally 2 ~ 5 s. In the actual project, the extrusion parameters are determined on the basis of the empirical value of the casting according to the optimization of the situation. In order to facilitate the adjustment of extrusion parameters, a separate cylinder is usually used to control the extrusion pin action.

For crankcase castings, the later improvement measures are to symmetrically arrange two extrusion pins near the bearing holes of the mold. As shown in the figure below, by adjusting the two main parameters of extrusion depth and extrusion delay, the effect of the secondary pressurization of the extrusion pins is optimized to reduce the rate of casting shrinkage. On the basis of the aforementioned measures, the shrinkage rate of the mold after the addition of two extrusion pins decreased significantly, and the defective rate was reduced from 4% to 0.2%. At the same time, in the 0.2% of shrinkage defective products, the size of the shrinkage hole is significantly reduced. Therefore, the squeeze pin program plays a better role in controlling the shrinkage rate of castings with increased wall thickness. However, in this improvement process, the casting shrinkage defective rate also had fluctuation phenomenon, through the optimization of the extrusion parameters extrusion depth of 15 mm, extrusion delay time of 2.5 s and the provisions of the extrusion pin service life (times/8000 die) and other related specifications, so that the casting defective rate stabilized in the vicinity of 0.2%.

The above figure shows the X-ray inspection comparison before and after the improvement of the casting shrinkage area. It can be seen that the casting shrinkage holes appear near the bearing holes, which are widely distributed and scattered, and the organization is relatively loose, because the bearing holes of the cylinder block need to be passed to the pressure lubricating oil, so there is a risk of oil leakage during the service period of the casting; after the improvement, the loose distribution of shrinkage holes can no longer be seen on the X-ray inspection photos, and the internal organization of the casting appears to be more dense.

Conclusion

1. Shrinkage hole is a common internal defect of casting, which is easy to appear in the area of larger wall thickness and higher mold temperature. It usually starts from several aspects such as mold design (pouring system, cooling system), process parameter setting and casting condition guarantee. For the wall thickness involved in larger castings, the traditional improvement measures can only play a role in alleviating the role, but not completely solve the problem.
2. Imitated the punch in the pressurization stage of the complementary contraction role designed two extrusion pin, the shrinkage hole region to play a second pressurized complementary contraction role, the effect is more obvious.

The post Aluminum alloy die casting: shrinkage analysis and countermeasures exploration first appeared on MindWell.

Aluminum die casting grinding steps

• Rough Grinding: The grinding process usually begins with rough grinding, using a coarser grinding wheel or sandpaper, to remove roughness, bumps, and irregularities from the casting surface. This step helps to initially smooth the surface.
• Medium Grinding: Next is medium grinding, using a medium grit wheel or sandpaper. This step further improves the surface finish, reduces dimensional deviations, and eliminates additional wear marks and unevenness.
• Fine Grinding: The fine grinding stage uses a fine-grain grinding wheel or polishing material to achieve the desired surface smoothness and quality. This step typically requires greater precision and finish.
• Polishing: Finally, parts may be polished to produce a high-gloss surface that makes it attractive and smooth. Polishing is performed to provide a special look and texture.

The goal of grinding is to eliminate defects that may occur during the casting process and improve the quality and accuracy of the surface to ensure that the aluminum die castings meet the design requirements. During the grinding process, quality control is often required, using measurement tools such as surface roughness meters or coordinate measuring machines to ensure that the size and shape of the parts meet specifications. This helps ensure the quality and performance of the end product.

In conclusion, aluminum die casting grinding is a critical surface treatment step used to improve the appearance and performance of aluminum die castings to ensure they are suitable for specific applications.

Grinding Advantages

Aluminum die casting grinding offers several benefits that help improve the quality, performance, and reliability of aluminum die castings. Here are some of the key benefits of aluminum die casting grinding:

1. Improved surface quality: Grinding can significantly improve the surface quality of aluminum die-casting parts. It eliminates roughness, bumps, dents, wear marks, and irregular shapes that may occur during the casting process, making the surface of the part smoother and more uniform.
2. Precision and Dimensional Control: The grinding process helps to precisely control the size and shape of aluminum die castings. This is critical to ensuring accuracy and consistency of parts, especially in applications requiring highly precise parts.
3. Eliminate Casting Defects: Porosity, heat cracks, or other casting defects can occur during the aluminum die casting process. Through grinding, these imperfections can be eliminated, improving the reliability and durability of the part.
4. Improved Appearance: Grinding improves the appearance of aluminum die castings, making them smoother, more uniform and with a high gloss. This is critical to visual appeal and product aesthetics, particularly in consumer electronics, automotive and decorative parts.
5. Reduce Part Weight: Grinding removes excess aluminum material, thereby reducing part weight. This contributes to lightweight design, improved vehicle fuel efficiency and electronic device portability.
6. Improves material strength: Grinding improves material strength and durability by removing irregularities and stress concentration points on the casting surface.
7. Customization and precision: The grinding process can be tailored to specific requirements to meet the performance and quality standards of different applications. This means that aluminum die-casting grinding can be adapted to the needs of various industrial fields.
8. Sustainability: Grinding helps extend the life of aluminum die castings, reducing waste and resource waste. Additionally, aluminum is a recyclable material that helps reduce environmental impact.

The benefits of grinding aluminum die casting include improved surface quality, accuracy and sustainability, making it an important surface treatment process in manufacturing. This helps ensure that aluminum die castings meet design and performance requirements, while improving product reliability and appearance.

Aluminum Die Casting Grinding Applications

Aluminum die-casting grinding is widely used in many fields, including but not limited to the following:

1. Automotive Industry: Aluminum die casting grinding is widely used in automobile manufacturing. It is used to improve the appearance, precision and performance of automotive parts, including engine parts, chassis parts, body components, and interior and exterior components. This contributes to the car’s fuel efficiency, lightweight design, and overall quality.
2. Aerospace Industry: The aerospace industry requires highly precise components to ensure aircraft performance and safety. Aluminum die-cast grinding is used to manufacture aircraft engine components, aircraft seat structures, aircraft wing components, etc.
3. Medical Equipment: Medical equipment manufacturing requires high-quality, precision components to ensure device reliability. Aluminum die casting grinding is used to manufacture housings, brackets, sensor parts, etc. for medical devices.
4. Electronics and Communications: Aluminum die castings play an important role in electronics and communications devices. It is used to manufacture chassis, heat sinks, connectors and other key components to ensure the thermal performance and reliability of equipment.
5. Industrial Equipment: Industrial equipment requires wear-resistant, corrosion-resistant and high-strength components. Aluminum die-cast grinding is used to manufacture various industrial equipment components, such as pump bodies, valves, gears, racks, etc.
6. Consumer Electronics: Consumer electronics products such as smartphones, tablets, and televisions use aluminum die castings for casings and body structures.
7. Energy field: The energy field requires efficient parts and components to ensure the performance and reliability of energy equipment. Aluminum die casting grinding is used to manufacture wind energy equipment, solar equipment, power transmission and distribution equipment, etc.
8. Sports and entertainment: Aluminum die castings are also used in sports and entertainment fields, such as bicycle components, sports equipment, car racing parts, etc.

Aluminum die-cast grinding has important applications in various industrial fields to improve the quality, appearance and performance of aluminum die-casting parts to meet the needs of different industries. This process helps improve the accuracy of parts and extend their service life, while making the product more sustainable.

in conclusion

Overall, aluminum die casting grinding is a vital surface treatment process that is essential to improving the quality, appearance, and performance of aluminum die castings. Through a well-designed grinding process, the surface quality of castings can be significantly improved, not only meeting design and performance requirements, but also increasing product reliability and sustainability. This process not only eliminates defects that may occur during the casting process, but also improves the precision and dimensional control of the parts, making them widely used in a variety of fields.

In addition, aluminum die-cast grinding also contributes to lightweight design, reducing the weight of components and improving the fuel efficiency of cars and the portability of electronic devices. It also helps improve material strength and appearance, allowing aluminum die castings to play a key role in automotive, aerospace, medical devices, electronics, industrial equipment, and more.

Finally, aluminum is a recyclable material, and the sustainability of aluminum die-cast grinding also helps reduce environmental impact while improving product quality. Therefore, aluminum die-casting grinding is an indispensable process in modern manufacturing, driving product innovation and improvement in a variety of fields.

The post What is aluminum die casting grinding? first appeared on MindWell.

Magnesium alloy die-casting and aluminum alloy die-casting are two common die-casting materials that can be used to produce lightweight parts, such as electronic equipment housings, automotive parts, etc. Although the two methods are similar, there are many differences between them. When choosing die-casting materials, you need to consider factors including product design requirements, performance requirements, cost budget, production batches, and expected use environment. Magnesium and aluminum have different properties and applicable scenarios. Which material to choose for die casting depends on your specific needs and applications. Let’s take a look at the difference between magnesium and aluminum die casting.

aluminum alloy

Aluminum is a very common metal used in die casting. It’s lightweight, reasonably performant, and inexpensive in cast metal.

Another big advantage of aluminum is corrosion protection. This makes its castings last longer; and it also has a higher melting point, making it stronger at higher temperatures than other metals, such as zinc.

The higher the aluminum content, the greater the risk of shrinkage or cracking; therefore, it is usually mixed with silicon or copper to increase fluidity, which makes the alloy harder and stronger.

magnesium alloy

Magnesium is often combined with other elements, including aluminum, to form lighter alloys.

Automotive applications reduce fuel costs, save energy and reduce emissions through the use of magnesium parts to reduce weight. Magnesium also takes less time to solidify after injection molding and is generally considered better castable than aluminum.

While magnesium offers some advantages, it is still not as stable as aluminum, it bends more easily under stress, and it is also somewhat more expensive than aluminum.

Difference Between Magnesium and Aluminum

1.Different properties of materials

Die-casting magnesium aluminum and die-casting aluminum are both metal alloy materials, but their composition and properties are different. The main component of die-casting aluminum is aluminum, which is formed after adding appropriate amount of copper, zinc, aluminum, magnesium and other elements. It has good mechanical properties and corrosion resistance, and can meet the requirements of many industrial fields. The die-casting magnesium aluminum is made of alloys of magnesium, aluminum, zinc and other elements. It has high strength and good comprehensive performance. It is an excellent light-weight and high-strength material.

The density

The density of magnesium is twice that of aluminum, so the volume of magnesium alloy parts with the same weight is much smaller. In the fields of machine parts and auto parts that require light weight and high sealing, magnesium alloy die-casting is the choice of many enterprises.

Strength

The strength of aluminum alloy is twice that of magnesium alloy, so in terms of high strength and wear resistance, aluminum alloy die casting is more suitable, at the same time aluminum alloy also has good maintainability, corrosion resistance and oxidation, more suitable for long-term use and high strength operate.

2.Different processing techniques

The processing technology of die-casting magnesium aluminum and die-casting aluminum are also different. Because the melting point of die-cast aluminum is relatively low, the melting and casting process is relatively easy, so it is used more in the production process. The melting point and melting temperature of die-cast magnesium aluminum are relatively high, and professional casting and processing technology are required, and the production process is relatively complicated.
Magnesium is more prone to cracking and compression when processing because it has different cooling properties and its die casting process also needs to be more complicated, while aluminum has the advantages of shock absorption and vibration resistance, and aluminum alloy products are also easier to process during the manufacturing process , and is able to provide finer details and finishes than comparable magnesium alloys.

3.Different fields of application

The fields of application of die-casting magnesium aluminum and die-casting aluminum are also different. Due to its good mechanical properties and corrosion resistance, die-cast aluminum is widely used in industrial fields, such as automobiles, aviation, electronics, digital and other fields. Due to its light weight and high strength, die-cast magnesium aluminum is widely used in some fields that require higher weight and strength, such as aviation, aerospace, sports equipment, etc. the

4.Cost

The cost of magnesium alloy die-casting is higher, because the production and synthesis technology of magnesium metal is very complicated, which may lead to higher original cost, energy cost and labor cost, so magnesium alloy die-casting is sometimes more expensive than aluminum alloy die-casting, of course, In this regard, product prices will also rise to a certain extent.

Magnesium VS Aluminum Die Casting

Choosing magnesium or aluminum alloy die casting depends on the specific needs of the part’s custom manufacturing, and both metals produce alloys that can be used for their respective applications. When trying to choose between magnesium and aluminum, your application direction is ultimately your choice.
If you need to make lightweight, ultra-thin-walled, high-toughness parts, magnesium alloy die-casting may be a better choice, and if you need to produce high-strength, corrosion-resistant, and oxidation-resistant parts, then aluminum alloy die-casting may be a better choice In addition, price and mechanical processing also need to be considered.

The post How to choose between magnesium and aluminum die casting first appeared on MindWell.

1. Manual deburring

This is the most conventional and widely used process in die-casting companies, including auxiliary instruments such as files (including artificial files and pneumatic files), sandpaper, belt machines, grinding heads, and so on. Disadvantages: labor expenses are high, efficiency is low, and intricate cross holes are difficult to remove. Applicable objects: Aluminum alloy die-casting components with tiny burrs and a basic product structure are not difficult to produce.

2. Die deburring

Deburring is done with the manufacturing die and the punching machine. Disadvantages: It necessitates the manufacturing of a punching die (rough die + fine punching die) and may necessitate the creation of a shaping die. Suitable for aluminum alloy die-casting components with relatively easy parting surfaces, with more efficiency and deburring result than manual work.

3. Grinding and deburring

Vibration, sandblasting, rollers, and other technologies are now employed in die casting plants for deburring. Disadvantages: The removal is not particularly clean, thus it may be required to manually deal with remaining burrs or collaborate with other ways to remove burrs.

Applicable objects: Suitable for small aluminum alloy die-casting parts with large batches.

4. Deburring by freezing

Cooling quickly embrittles the burrs, which are subsequently removed by spraying bullets. The equipment costs between 200,000 and 300,000 yuan. Objects that can be used: Suitable for aluminum alloy die castings with fine burrs and thin walls.

5. Thermal deburring

It’s also known as thermal energy deburring and explosion deburring. Insert a combustible gas into an equipment furnace, then let the gas to burst instantaneously due to the action of some media and circumstances, and use the energy created by the explosion to dissolve and remove the burr. Disadvantages: costly equipment (millions of dollars), high technical requirements for operation, limited efficiency, side effects (rust, deformation); suitable objects: mostly employed in high-precision components areas like as automotive and aerospace.

6. Engraving machine deburring

The cost of the equipment is not prohibitively high (tens of thousands of dollars). Suitable for basic space structure and simple and regular deburring position.

7. Chemical deburring

The deburring procedure on metal components may be accomplished automatically and selectively using the electrochemical reaction concept. Applicable object: suited for difficult-to-remove internal burrs, suitable for tiny burrs (thickness less than 7 wires) on pump bodies, valve bodies, and other items.

8. Electrolytic deburring

An electrolytic processing procedure used to remove burrs from aluminum alloy die-casting. Burrs in concealed areas of cross holes or components with complicated forms in aluminum alloy die castings can be removed by electrolytic deburring. The production efficiency is good, and deburring time is often in the tens of seconds. Disadvantages: Because the electrolyte is corrosive to some extent, and the sections surrounding the burrs are also electrolyzed, the surface loses its original sheen and even affects dimensional accuracy. After deburring, aluminum alloy die castings should be cleaned and rust-proofed. Suitable object: It is useful for deburring gears, connecting rods, valve bodies, and crankshaft oil passage holes, as well as rounding sharp edges.

9. High pressure water jet deburring

Using water as the medium, employ its quick impact to remove burrs and flashes after processing while also achieving the cleaning goal.

The disadvantage is that the equipment is pricey.

Typical applications include the heart of vehicles and hydraulic control systems in engineering machines.

10. Ultrasonic deburring

To remove burrs, ultrasonic waves produce sudden high pressure. Applicable objects: mostly for some tiny burrs; normally, if the burrs must be examined under a microscope, ultrasonic procedures can be used to remove them.

11. Abrasive flow deburring

It is tough to deal with hole burrs with conventional vibration grinding. Typical abrasive flow processing method (two-way flow) forces the abrasive through two vertically opposed abrasive cylinders, causing it to flow back and forth in the channel created by the workpiece and the fixture. Any confined space through which abrasive material enters and flows will provide an abrasive effect. The extrusion pressure is adjustable from 7 to 200 bar (100 to 3000 psi), making it suited for a variety of strokes and cycle times. It can handle 0.35mm microporous burrs without secondary burrs, and the fluid properties can manage burrs in difficult situations.

12. Magnetic deburring

The magnetic grinding process is governed by a strong magnetic field, in which magnetic abrasives are arranged along the magnetic field lines, adsorbed on the magnetic poles to form “abrasive brushes,” and generate a certain pressure on the workpiece’s surface, while the magnetic poles drive the “abrasive brushes.” Maintain a particular distance and travel over the surface of the workpiece as the “brush” rotates to complete the finishing process of the workpiece’s surface.

Low cost, wide range of processes, simple operation

Grinding stone, magnetic field intensity, workpiece rotation speed, and so on are all process components.

13. Robot grinding unit

The idea is the same as hand deburring, only the power is transferred to a robot. Flexible grinding (change of pressure and speed) is accomplished with the help of programming technology and force control technology, and the benefits of robot deburring are highlighted.

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