Hot Chamber Die Casting

In metalworking industries, hot chamber die casting has gained a significant rise up to 8% for its speedy, and economical viability in the global market. The process replicates intricate detailed, and high quality parts with minimal turnaround. Moreover, it offers economic advantages, when employed for large volume batches. The hot chamber die casting process is recognized for its precision, accuracy, and optimal performing parts because of the integration of CNC systems in designing parts configurations. Therefore, from automotive, and aerospace to consumer products, its role is vital where exact specification parts are crucial. Furthermore, it’s a relatively cheap and fastidious manufacturing process, unlike other conventional techniques.

What is Hot Chamber Die Casting?

What is Hot Chamber Die CastingCompared to conventional casting methods, hot chamber die casting follows the the same mechanism. It involves the placement of molten metal into the die cavity. Then, a high pressure injection shot is inserted that swiftly turns the molten metal into the shape of a die (which entails the shape of the desired part) upon solidification.

This cycle repeats until you reach the desired volume of parts requirements. Since hot chamber diecasting is optimally used for low melting temperatures. So, a furnace, and die setup are required for this specialized process. Different from cold chamber die casting, this furnace is built inside and equipped with a die-casting machine. Before going into process details, it is necessary to understand the assembly requirements for the hot chamber die-casting process. Basically, a die-cast machine consists of six parts, including;

Heating Furnace

The heating furnace is a fundamental part that melts the raw solid metal into a liquified form. It is specifically designed to allow high temperatures to prevent premature cooling of the intended alloy.

Gooseneck

The gooseneck serves as a pathway to make a smooth transition of molten metal to die. In other terms, you can say, it bridges the gap between the feeding line and the injection mechanism. It’s typically made of forth durable metal like cast or forged steel. Moreover, this component is always immersed in the molten metal pool to resist thermal impacts during the casting operation. Manufacturers must count on to replacement of goosenecks under high swear conditions in large production runs.

Nozzle

As the name implies, the nozzle is responsible for the seamless regulation of casting metal into the die by applying high pressure gas. Meanwhile, the gooseneck plays a gateway role in making a smooth transition in the flow mechanism.

Hydraulic Plunger

A hydraulic plunger/piston is primarily used for maintaining high pressure in the die by utilizing gas or lubrication oil as a power source. The plunger tends to move upward, and downward. The upward movement of the piston plunger lets molten metal inside the hot chamber, and then the piston’s downward movement transforms into the desired configuration.

Casting System

At last, here comes the die system itself. A die system is composed of two identical parts: cavity and ejector. Typically, the die used in hot chamber die casting is made of steel like other casting processes.

Ejection

Ejection is the final phase in the hot chamber casting process. The operators mechanically took out the cast part by ensuring the part’s integrity and chilled it back to solids. After successful ejection, cast parts may still undergo further post processing treatments. Some commonly finishing processes include: anodizing, polishing, and painting.

Hot Chamber Die Casting Process: A Step-by-Step Guide

Hot Chamber Die Casting Process

The process’s success can be ensured by complete familiarization. Here’s a step-by-step guide to the hot chamber die casting process:

Step 1. Metal Alloy Melting

The initial step involves the melting of alloy, prominently, zinc or magnesium in the furnace which entails a combustion chamber to burn fuel and melt the intended metal alloy. The optimum temperature required is around 1220°F to 6152°F depending upon the used metal properties.

Step 2. Injection

Then, the liquid metal is uniformly placed inside a lubricated die by uplifting the plunger. Here, a crucible is used for fine injection of molten metal to avoid any overspill issues. After this, the die is enclosed for the next phase.

Step 3. Applying High Pressure

This step tends to transform the liquid metal into the desired shape by applying high pressure, typically ranging between 5 – 35 MPa through the plunger/piston. This step determines the outcome of the process. Therefore, manufacturers must ensure, there’s no poking hole inside the mold cavity to avoid any chance of shrinkage in parts.

Step 4. Ejection & Solidification

The shape is then cooled down and the product is ejected out of the mold cavity. This die-cast product is then further inspected for any defect to ensure its quality. Alongside, the cycle repeats according to the aforementioned steps.

Metals Used in Hot Chamber Die Casting

As mentioned above, the hot chamber die-casting process is appropriate for metals with low melting points. This way, zinc, and magnesium are notably acquired for casting applications. Let’s discuss the critical aspects of these metals in below mentioned table.

Table: Characteristics of compatible metals for HCDC

Metal Density (g/cm³) Melting Temperature (°C) Compatibility Aspects
Zn 7.14 419-426 Suitable due to moderate melting point and good fluidity,
Mg 1.738 650-700 Excellent due to low melting temperature, good fluidity, and minimal die wear
Pb 11.34 327.5 Good due to low melting temperature and moderate fluidity, suitable for specific applications

Zinc

Zinc Die Cast Parts

Primarily, zinc is a tremendously low melting point (419℃) metal. Its lightweight nature, high strength, ability to resist corrosion, and high fluidity make it an ideal choice for die-casting applications. On top, it’s relatively a cheaper alloy than magnesium, and lead. Moreover, zinc possesses remarkable features such as; hardness, and resistance to wear, and tear. This ability helps zinc to endure harsh conditions. Zinc permits low porosity issues in die casting process.

Magnesium

Magnesium Die Cast PartMagnesium is a prime metal for hot chamber die casting. It’s lightweight, resilient, thermally stable, and recyclable with a density of 1.7g/cm³. Mg is chemically resilient and most importantly the easiest alloy to cast. Additionally, it possesses high shielding abilities to resist radio frequencies and electromagnetic interference. Similarly to zinc, magnesium possesses fewer chances of porosity, and less oxidizing capabilities. Therefore, it lends its applications across automotive, aerospace, and electronic devices.

Lead

Lead Alloy Die Cast PartLead has remarkable castability, weight reducing ability, and a low melting point that makes it a compatible candidate for casting applications. It sets it apart from other alloys because of its distinct malleability, ductility, and ability to meet stringent, and exact parts requirements for industrial use products.

Advantages of Hot Chamber Die Casting

Here are some of the commonest benefits of hot chamber die casting.

  • The production cycle rate of the hot chamber die casting process is relatively faster than other conventional methods. On average, it can process 15 cycles per minute.
  • Hot chamber die casting helps sophisticated shape products with relative ease, and parts entail high dimensional accuracies.
  • The process is highly economical when commencing for bulk volumes.
  • Part manufacturing in hot chamber die casting isn’t complex unlike investment casting and gravity die casting.
  • The maintenance cost is comparatively low as compared to cold chamber die casting (see more on hot chamber die casting vs. cold chamber die casting). Because the direct transfer of alloy is carried out during the process to mitigate potential risks of porosity, and shrinkage.
  • Product manufacturers benefit from the process of shaping parts with tighter tolerances, accurate dimensions, and smooth texture finishes with minimum post processing requirements.
  • Parts made through hot chamber die casting possess greater strength up to 25~30%than sand casting.
  • A die-casting mold features versatility in terms of using multiple cavities in a single die.
  • The tooling life in hot chamber die casting is frequently long, due to low temperature requirements for part manufacturing.

Disadvantages of Hot Chamber Die Casting

Some of the disadvantages of hot chamber die casting include:

  • Hot chamber die casting is limited to accommodate only nonferrous metals with low melting temperatures.
  • Risks of porosity, flashing, and blister formation on parts are higher in hot chamber die casting as compared to other casting techniques.
  • The lower the production volume, the higher the amortized cost per part. It means that hot chamber die casting is effective, and economical for producing parts in bulk.
  • The cost of utilities, and auxiliaries used for instance furnaces, molds, and dies imparts high initial expenses to the project.
  • Hot chamber die casting is a labor intensive process.

Tips on Selecting Hot Chamber Die Casting Process

There are several determinants to keep into consideration while selecting a hot chamber die casting process for your projects. Here are some expert tips that help you make a wise selection of process;

  • Die Casting Alloy: The process applicability relies on low melting point materials. Usually, the hot chamber casting process is preferred for zinc, lead, tin, and magnesium. These alloys have minimal melting temperatures below 600°C. Therefore OEM manufacturers must be aware of casting alloy properties before initializing die casting projects.
  • Part Complexity: Normally, manufacturers intend to employ hot chamber die casting for less intricate products. The parts with cylindrical, and radial shapes can be made through vertical cold chamber die casting equipment. So, being knowledgeable on part specification is a must to make the most out of the process.
  • Cost Considerations: Evaluate the overall costs for the process including: tooling, equipment, material, and labor expenses. The hot chamber casting is frequently efficient for large volume runs. The costing analysis of the project majorly depends on volume, budget, machining setup, and time frame.
  • Finishing Requirements: The optimal surface finishing is another factor to consider. If you’re more concerned about parts with higher finishing textures, then go for hot chamber die casting. It generally produces parts with smooth surface finishing.
  • Take the Expert’s Opinion: The successful implementation of the process demands certain things to consider for instance, budget, timeline, design specs, and several other things. Therefore, it is always recommended to consult with an expert like CFS Foundry to make a wise choice for your project requirements.

Applications of Hot Chamber Die Casting

As discussed, hot chamber die casting produces reliable parts with exceptional durability and fine surface finish. From automobile parts to aircraft components, it plays a key role in part manufacturing to meet industry requirements. Let’s figure out some of the applications of this technique across manufacturing sectors.

Automotive Industry

The automotive industry is the primarily consumer of die casting parts. The casting products made through hot chamber die casting are heavily used in automobiles’ interior, and exterior components to improve optimal performance, and workability. A few examples include; gearboxes, enclosures, housings, engine blocks, and recreational vehicles.

Consumer Electronics

Hot chamber die casting plays a central role in making parts for electronic industries. The high strength and dimensional accuracy are key features that lend their use in devices like smartphones, laptops, and handy gadgets.

Medical Devices

The stringent, and highly durable parts are basic needs of the healthcare industry. This way hot chamber cast parts play an important role in creating housings, and enclosures of diagnostic devices. Some common examples include: medical implantable devices, and syringe components.

Aerospace Industry

In aerospace industries, hot chamber die casting makes strong yet lightweight parts to enhance the overall functionality and performance of aircraft components. It facilitates in production of parts for jet engines, landing gear, and structurally integrity-oriented parts. Moreover, parts having detailed features are easier to bring through this incredible process.

Industrial Manufacturing

The manufacturing sectors heavily rely on the hot chamber die casting process. The process exploits to create tools and dies for injection molding. Moreover, hardware, consumer goods, and telecommunication parts like antennae can be cast through hot chamber die casting.

Contact CFS Foundry for Hot Chamber Die Casting Services:

At CFS Foundry, with a decade of experience in die casting, our technical experts are committed to bringing preeminence, and reliability to your intended project.

Our engineers help you make DFM analysis, wise selection of casting material, and process by guaranteeing high quality and best customer service. We possess advanced machining equipments geared by experienced professionals to bring your parts to practicality in a short turnaround.

Moreover, we provide casting services for a broad prospects. Whether you need intricate parts from medium to large volumes, we have the facility to meet exact specifications and requirements in your affordable budget.

For any inquiries or to discuss your die-casting project, feel free to send us your drawings to sales@investmentcastchina.com. Our engineers will analyze your design, and provide you an instant quote with assistance from start to end.

FAQs  

Q1. Is aluminum can be cast through hot chamber die casting?

Typically, aluminum die casting is not compatible with hot chamber die casting because it has a very high melting point of 660 °C. Normally, metal suitability depends upon its thermal characteristics. Therefore, due to higher melting temperature, aluminum may pose the risk of damaging machine components like the gooseneck, and nozzle.

Q2. What’s the key difference between hot and cold chamber die casting?

The basic difference lies in the material’s compatibility. For example, metals with higher melting points, above 600°C, such as aluminum, copper, and brass are likely to be cast through cold chamber die casting machines. In contrast, low melting point temperatures are cast through the hot chamber casting process. Moreover, other factors, like machining or assembly setup, part specifications, cycle time, and intended volume play a key role.

Q3. Any alternatives to the hot chamber die-casting process?

Yes, there are multiple alternatives to choose from. The ultimate choice depends upon your product design and complexity. Some commonly employed casting processes include:

  • Investment casting
  • Cold chamber die-casting
  • Gravity die casting

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