Casting Buyer Series - Introduction to Die Casting
Die-casting proves to be an exciting subject matter. Although it is a bit broad concept with some technicalities, still, it is straightforward to understand.
So we present to you this buyer series. In these courses, we have prepared some introductory knowledge of die casting to help people who are not very familiar with die casting.
1.Introduction to Die Casting
Die casting, also known as high-pressure casting, uses high pressure to press molten metal into a metal mold with complex shapes at high speed. Then, they solidify under high pressure to form a casting. It is a liquid metal casting process.
The speed of molten metal filling can reach 30-60m/s. The purpose of such a high speed is to make the molten metal fill the inside of the mold in an atomized manner. Once the mold cavity is filled, the die casting machine applies high pressure to the casting, causing it to solidify. Usually, the pressure is 25Mpa-135Mpa.
Die casting can be used to produce alloy products such as aluminum alloy, magnesium alloy, zinc alloy, and copper alloy. The product has good precision and high production efficiency, so they have a wide application.
A machine that produces die castings is called a die casting machine. The size of the clamping force distinguishes the size of the die-casting machine. We ensure that the mold can be locked during the die casting process by choosing the right machine.
Types of Die Casting Machines
According to different production methods, die casting machines can be divided into cold chamber die casting machines and hot chamber die casting machines. The cold chamber die casting machines range in size from 160 to 9000 tons.
At present, the more well-known is Tesla’s 6,000-ton die-casting machine used to produce the rear body frame of the car. The hot chamber machine is a small multi-slide die-casting machine that can produce very precise small parts, such as 8-ton, 10-ton, and 12-ton die casting machines. Large hot chamber die casting machines can reach 600 tons.
Die Casting Molds
Die-casting molds are process equipment used to produce die-casting parts. The die-casting mold consists of two parts: fixed mold and movable mold. The fixed die is fixed on the fixed die mounting plate of the die casting machine.
The movable mold is fixed on the die-casting motorized mold mounting plate and moves with the opening and closing of the machine. The closed area of the fixed mold and the movable mold constitutes the cavity of the mold, that is, the product’s shape.
Putting the Elements Together
Die-casting alloys, die-casting machines, and die-casting molds are the three major elements of die-casting production, and none are indispensable. Therefore, the so-called die-casting process comprehensively utilizes these three elements to produce castings with excellent appearance and internal quality stability.
There are other die casting processes that can be used to make high-density die castings. Such as high vacuum die casting, semi-solid die casting, and squeeze casting.
2.History of Die Casting History of Casting
History of Casting
Between 3000 and 2500 BC, people in the Middle East had mastered lost wax casting. Then, in 600 BC, the Chinese started to use cast iron for making ironware. The cast-iron technology began to spread across Europe in 1200 AD.
In the 16th century, France invented the use of sand as a mold material, which is a simple sand casting. In 1740, the English people invented cast steel, and the metal forming process has significantly been developed at this time.
History of Die Casting
The invention of die casting originated in 1849 when a man named Sturgiss invented the world’s first die casting machine. As shown in the picture, this simple machine is used to make the type of printing press we see today. The molten lead alloy is injected into the mold through a nozzle by manually operating a plunger. So people also call this a lead kettle.
Twenty years later, in 1868, a man named Babbage applied this process to computer parts and began to die-cast products in various shapes. Then, in 1892, he began producing spare parts for phonographs and radios.
In 1885 Otto Mergenthaler invented the Linotype, the machine capable of die casting an entire line of text into a single type. This brought unprecedented innovation to the printing world. After the printing industry had entered large-scale industrialization, the traditional hand-pressed type was replaced by die-casting.
After 1900, Edison’s phonograph began to be widely used, which significantly promoted the development of the die-casting industry in the face of the demand for mass production.
In 1907, Herman Doehler invented the first high-pressure casting machine to produce zinc alloy products.
In 1914, aluminum alloys were first used as die-casting alloys to produce products on hot-chamber die-casting machines.
Before 1930, the aluminum alloy process has been using hot chamber die casting machines. But starting in the 1930s, cold chamber die casting machines began to appear. Because aluminum alloy will react with iron, it is not suitable to soak aluminum alloy in the feeding system of the hot chamber machine for a long time. As a result, the cold chamber die casting machine was invented.
From 1950 to 1960, the die casting industry developed rapidly.
History of Die Casting Alloys
Lead alloys and tin alloys were originally used in die casting. However, before the First World War, zinc alloys developed rapidly, and lead-tin alloys gradually decreased. Next, magnesium and copper alloys rose to the limelight as die casting alloys.
After 1930, aluminum, magnesium, and copper alloys have been greatly developed and are still in use today. The research on alloys is still ongoing, the properties of alloys are constantly improving, and new alloys are produced.
3.Advantages of Die Casting
Advantages of die castings
Die casting holds several irresistible advantages. It has sure contributed to the advancement of other manufacturing industries. So, let’s see what these advantages are.
- Can design very complex products
- Products that require high precision can be formed.
- Help make the wall thickness of the product to be very thin.
- The surface quality of die castings is relatively high
- Die casting products can be subjected to subsequent surface treatment, such as electroplating, oxidation, painting, etc.
- Die casting products can also be recycled, saving materials, environmental protection, and safety.
Advantages of alloy materials
We can not underestimate the relevance of alloys in the die casting industry. Also, there are many kinds of alloys suitable for die casting. Mainly aluminum alloys, magnesium alloys, zinc alloys, and high aluminum-zinc alloys, Copper alloys can also be used for die casting.
However, other materials, such as Al-Mg alloys, can also be die-cast. The mechanical properties of die-cast alloys are close to the intermediate levels of the main metals in the alloy.
- Die-cast alloys are stronger than plastics.
- Mechanical properties of die casting alloys are comparable to powder metallurgy, brass, rebar.
- Compared with plastics or other composite materials, die-casting alloys have a greater cost advantage in meeting the strength requirements if the product requires strength.
- Sturdy appearance with a metallic feel
- Good strength
- Good impact resistance
- Sound insulation performance
- Multiple separate parts can be combined into one part.
- Inherent electromagnetic shielding
Process Advantage
The process advantage include the following;
- Good theoretical studies in thermodynamics, heat transfer, liquid flow parameters
- These studies are of great help to the improvement of the die casting process
- Modern die casting equipment provides a better guarantee for the process. Ensure the precision of die castings. Ensure the stability of die casting quality.
- The precision of die castings is high, and the draft angle can be reduced.
- Within certain limits, no machining is required.
Economics
Beyond the industrial and material benefits of the die casting process, it also holds immense economic benefits. This involves how die-casting influences the financial aspect of society.
- Die casting has a better cost advantage when the product volume is large.
- In the case of low output, it also has a certain cost advantage.
- Die casting can complete complex and high-precision products so that multiple parts can be combined into one. Reduce machining and assembly.
- Die-cast alloys are extremely reliable through decades of use, testing, and data analysis.
4.Industries for Die Casting Applications
The application of die casting cuts across several industries. This shows how versatile and relevant die casting is.
- Agriculture: this involves several agricultural pieces of machinery and process technology. Examples include agricultural pumps, bespoke components, pulleys, fabricators, irrigation system components, etc.
- Horticulture: this involves its usage in the fabrication of garden equipment.
- Automobile: here, we use die casting for manufacturing various auto parts. This includes carburetors, wheels, wheel spacer, valve covers, engine block, etc.
- Office furniture: you can see the applications in office chairs, tables, and other furniture
- Architecture: this involves construction parts such as building frames, wooden frames, and superstructures for roofing.
- Hand-operated tools: this includes firearms, parts of oxygen pumps, rotary saws, etc.
- Household appliances: several pieces of equipment in the home are die casting products. Examples include standing fans, music boxes, radio, etc.
- Instrumentation: this involves several classes of instruments like musical instruments, medical instruments, etc.
- Electrical and electronic equipment: die casting is used for electrical housing parts for electronic equipment.
Note: The biggest market for the die casting industry is auto parts.
5.When Designing, Think More About Manufacturing
There are standardized operation methods in the die casting industry, so it is best to consult the appropriate experts and carry out resource analysis.
For optimal results, you should incorporate the needs of the manufacturing process during early product design. And product designers need to work closely with die casting staff.
To maximize product and process benefits, here is a summary of what you need.
- An established die casting supplier with the ability to provide design optimization to its customers.
- Good design and development
- Good communication
Poor design and development will result in the projects not going well, And poor or complex communication will result in output lower than expected.
Most companies spend only 5 percent of their budget on design. Still, design typically accounts for 70 percent of the cost of the product –partly because 80 percent of quality problems are unwittingly designed into the product itself.”
It spends a small amount (such as 5%) as research and development, but in the cost of the product, the design has a very large impact on the cost, and even 80% of the problems in the post-production are caused by poor design.