Zinc die casting

What is Die Casting?

Die casting is a metal casting process which is characterized by pressing molten metal into the mold cavity. The mold cavity is made using two hardened tool steel molds that are worked on during processing and work similarly to injection molds. Most die-casting is made from non-ferrous metals, especially zinc, copper, aluminum, magnesium, tin, lead, and tin-based alloys. Depending on the type of metal being thrown, a thermal or cold engine is used.

Zinc die casting

Zinc die casting

The zinc die casting process is very popular for making parts in building and industrial fields, but the most common application is in the automotive industry. In fact, cars have different parts that can be made through die casting, in such a way that the modern process of die casting was originally started for the automotive industry.

With the casting process often no further machining is needed after casting: not only is the accuracy up to 99.8%, but the casted products can also be used raw because they have a pleasant finish. The use of zinc die casting is almost 28% in the automotive industry, followed by the building and hardware sector.

Zinc has become one of the most important metals in the auto parts industry, especially for products such as door lock housing, pawl, gears and retractor pulleys in seat belt systems, but also for camshaft and sensor components. By using this metal and its alloys, it is possible to achieve strength, ductility, and flexibility that would not be possible with other materials.

In addition, zinc can be the right choice to get high-quality aesthetic components, with tight tolerances that are not possible with other materials, and to get embossing and grooves for mechanical components or gears.

Zinc Die Casting Mechanisms in Automotive

As said before, the automotive industry is the most common die casting application: using zinc and its alloys makes it possible to produce components that are able to achieve high aesthetic quality, with tight and narrow tolerance for shape morphology. Zinc alloys are also used for coatings because of its many benefits, such as improving the anti-corrosion properties of zinc which are already impressive.

Below you can find a number of possible examples of zinc plating:

  • Interior aesthetic section
  • Sunroofs Section
  • Mechanical parts
  • Engine and other underhood components
  • Power steering system
  • Parts and brake system
  • Air conditioning components and systems
  • Chassis hardware
  • Parts in the seat belt system
  • Components of climate control
  • Fuel system

Advantages for Zinc Die Casting:

  • An efficient & economical process offering various forms & forms possible.
  • High-Speed ​​Production
  • Dimension Accuracy & Stability
  • Strength & weight
  • Several finishing techniques are available
  • Simple Assembly

The Die Casting process began with the use of lead and lead alloys, magnesium and copper alloys which were quickly followed, and in the 1930s, many modern alloys still in use today are available. This process evolved from casting low-pressure injection to modern high-pressure injection of 4,500 pounds per square inch. The modern process is capable of producing high integrity, clean casting forms with excellent surface finishes.

Zinc casting alloy is a strong, durable and cost-effective engineering material. Their mechanical properties are competitive and are usually higher than cast aluminum, magnesium, bronze, plastic and most cast iron.

Zamak 3 zinc casting

We offer ZAMAK 3 die casting for manufacturing ZAMAK 3 products. Our ZAMAK 3 products, productions capabilities, and warehousing facilities will give you quality parts at competitive prices. ZAMAK 3 is the most popular of the ZAMAK series of alloys for zinc die casting due to its castability and dimensional stability.

ZAMAK 3 Properties:

Ultimate Tensile Strength: psi x 103 (MPa)41 (283)
Yield Strength – 0.2% Offset: psi x 103 (MPa)32 (221)
Elongation: % in 2″10
Shear Strength: psi x 103 (MPa)31 (214)
Hardness: Brinell82
Impact Strength: ft-lb (J)432 (58)
Fatigue Strength Rotary Bend – 5×108 cycles: psi x 103 (MPa)6.9 (48)
Compressive Yield Strength 0.1% Offset: psi x 103 (MPa)604 (414)
Modulus of Elasticity – psi x 106 (MPa x 103)12.46 (85.5)
Poisson¡¯s Ratio0.27
Density: lb/cu in (g/cm3).24 (6.6)
Melting Range: ¡ãF (¡ãC)718-728 (381-387)
Electrical Conductivity: %IACS27
Thermal Conductivity: BTU/ft/hr/¡ãF (W/m/hr/¡ãC)65.3 (113.0
Coefficient of Thermal Expansion: 68-212¡ãF µin/in/¡ãF (100-200¡ãC µm/mm/¡ãC)15.2 (27.4)
Specific Heat: BTU/lb/¡ãF (J/kg/¡ãC).10 (419)
Pattern of Die Shrinkage: in/in.007

Zinc Die Castings Applications

Sporting Goods

– Cost-saving approaches to machined components;

– Coatings to match mating zinc parts;

– Strength for tough applications;

Zamak 3 die casting

Zamak 3 die casting

Medical

– Innovative capabilities;

– Precision designs as cast;

– For use in many difficult applications;

Switch

– Multiple cavities for cost savings;

– Multislide;

Fasteners

– Many sizes of panel nuts already tooled;

– High speed tapping capabilities;

Connector

– Four slide technology to eliminate costly secondary;

– Barrel plating for electroless nickel offers cost-effective protection and aesthetics;

– Excellent conductive alloys;

Fiber Optics

– Capable of casting complex designs;

– Close tolerance, as cast, components;

– Equipment and experience to provide small components;

Appliances

– Thin wall castings with the strength to hold up in applications;

– Surface finishes provide wear resistance ;

– Alloys designed for application specifics ;

Automotive

– Capability to incorporate multiple components into a single zinc casting ;

– Corrosion-resistant castings and platings ;

– Secondary tapping capabilities ;

– Zinc is an excellent dampening material ;

The Detail of Zamak 3 zinc casting 
Model No: Zamak 3 zinc casting
ProductName: Zamak 3 or 5 die casting
Product Origin: China
Brand Name: CNM TECH
Price Terms: FOB SZ
Payment Terms: T/T CIF L/C
Supply Ability:  300,000-400,000sets/month
Delivery Lead Time: around 30 days
If you want to purchase or know more information about Zamak 3 zinc casting,

Zinc die casting parts

Zinc Die Casting Description :

We use four top-quality zinc alloys for our zinc die casting parts – Zamak 3, Zamak 5, ZA-8 and Zamak 2 — because they offer unique advantages for creating high-precision die castings.

Zamak 3:

As the most popular zinc alloy, Zamak 3 features exceptional ductility and impact strength. It works very well with multiple plating and finishing options,

Zamak 5:

Typically used in automotive and small engine applications, Zamak 5 exhibits excellent creep resistance, hardness, and strength.

Zamak 3 or 5 die casting parts?

For all our zinc die castings we use either Zamak-3 or Zamak-5 Zinc Alloy. Special. The Alloying is

done in our fully automatic In-house Zinc Alloying section where we manufacture all kinds of Zinc Alloys for Die Casting. Our daily Zinc Alloying capacity is 16 Metric Tonnes. Every  Alloy Heat is tested by a computerized Spectrometer for metallurgical composition.

We would be happy to quote for your requirements of low-cost high volume small precision

 Zinc Die Casting components weighing in the range of 0.25 gms to 125 gms.

We specialize in a rare combination of both – Accurate Sizes & Decorative Surface Finish

ZA-8:

Even stronger than Zamak 3 and 5, ZA-zamak8 is the ideal choice for hot chamber casting projects. It also works well with multiple plating and finishing options.

Zamak 2:

Compared to other Zamak alloys, Zamak 2 offers higher creep performance and long-term strength and hardness. It serves as an excellent bearing material and has been known to eliminate the need for bushings and wear inserts in die-casting components.

Zamak 5 die casting

Zamak 5 die casting

Zamak 3, Zamak 5, ZA-8, and Zamak 2 is well suited for the die casting process due to their ability to:

– Produce very thin walls and near net shapes

– Achieve high levels of accuracy

– Offer temperature flexibility up to 150° F

– Provide reliability with superior bearing properties

– Exhibit increased wear resistance

Please send us either your samples, drawing and other details and we will send you our quote immediately.

Zinc die casting

The process of die casting with pressure injection can be followed until mid-1800. The components used were tin and lead, but the use has disappeared with the introduction of zinc and Aluminium alloys. This process has evolved over the years, from low-pressure injection molds to casting molds at pressures of up to 4,500 psi. The process can create high-quality products with excellent end surfaces.

Die Casting is an economical and efficient process for making various shapes. Considered superior to other manufacturing techniques, it is durable and aesthetic and combines perfectly with other parts of the machine that are part thereof. Dying has many advantages. Among these, the main is its ability to produce complex forms with a higher tolerance level than other mass-production methods. Thousands of identical prints can be produced before you need to add new mold tools.

Zinc die casting

Zinc die casting

High Die-pressure is a manufacturing process where aluminum that has been melted is injected by a casting machine under extreme pressure on steel or molds to make the design and detail parts of the model you want to make. Casting in tons of universal tightening. This record reflects the amount of pressure given on the matrix. The engine size varies from 400 to 4000 tons.

There are many advantages to using the die casting process compared to others. Die casting produces parts with thinner walls, narrower size limits and processes can be accelerated. Labor costs and finishing are the lowest with the dice. This process facilitates to obtain intricate forms with narrower tolerances. Unlike the forgery process, you can insert the kernel into the product created by this process.

Forms that cannot be obtained from rods or tubes can be easily achieved with casting. The number of operational processes is smaller, which leads to the reduction of waste materials.

Die casting is used when you need a stable, dimensional and durable component. They withstand heat and maintain a good level of tolerance, an important condition for each part of a good machine. They are stronger and lighter than the part made by other printing methods. Its parts are not welded or screwed, which greatly increases its efficiency. Another advantage is the many workarounds that you can get with the launch. Surfaces can be smooth or textured, which facilitates the application and its use.

Hopefully, this information can help you and thank you for reading the article about Zinc Die casting.

Zinc die casting Parts is referred to as the hot-chamber process. It is the method by which zinc (zamak) is heated under high temperatures and the molten material forced into a zinc die casting mold under high pressure to produce product with a similar shape as the die. As the metal moves through the die, air escapes through the vents. Once the die is full, the high pressure is maintained until it solidifies and the die is separated to release the finished zinc cast. After casting, no further modification is usually required.

Use of Zinc Die Casting

Zinc (zamak) is known for its high strength, accuracy, ductility, ease of casting, high thermal and electrical conductivity, and long life. As such, the zinc die casting is applied in the manufacture of high quality industrial and building materials. Die casting started in the automotive industry and it is still widely used in the manufacture of automotive components. The door locks casing, pulley, and the camshaft are some of the car parts that are made of zinc casting. In the construction industry, zinc die casting is utilized in the manufacture of components such as door knobs, faucets, and roofing. On the other hand, there are many zinc casting machine parts, such as electrical fittings.

Zinc Die Casting Process

Zinc is cast using the hot-chamber process due to its low melting temperatures. Cold chamber process is applied in the casting of metals with high melting temperatures such as the aluminium. The zinc die casting process involves the preparation of the metal, die preparation, and finishing. It commences with the preparation of the die followed by the metal. Notably, the die can be used once or severally depending on the component being manufactured. If it was used before, it should be lubricated to ease the removal of the cast metal. Afterwards, the ejector die half and the cover die half are screwed. The cover die half has a sprue through which the molten metal is injected while the ejector die has ejector pins for removing the castings.
Preparation of the die is followed by melting of the ZA or the ZAMALAK alloy on a furnace. The physical properties of the product dictates the choice of the alloy. Due to metal hardness and strength, the furnace temperature is usually very high. The oxidized parts of the metal are removed at this stage to raise the purity of the finished product. Various chemicals can be added to improve physical properties of the finished alloy.
Once the molten metal is prepared, it is injected into the feed system under high pressure. Most of the systems have several dies for efficiency and mass production. The raised pressure ensures that the molten zinc alloy gets into the mold as fast as possible, no air gets into the molten metal, and the expulsion of the air in the die through the vents. After filling the die, the pressure is raised further until the zinc alloy casting solidifies. The process also involves cooling using water. Then, the two dies are separated and the metal cast is removed. This is followed by the cleaning of the feed system to get rid of the flash. Further finishing can be carried out depending with the final use of the product. The runner that is removed from the final product and the flash are usually recycled.
Aluminium die casting

Capacity To Meet Your Aluminum, Magnesium, Zinc and Vacuum Die Casting Needs.

Aluminum Die Casting

Providing high-quality Aluminum die casting parts at competitive prices requires modem die casting equipment. To reduce the effects that extreme cooling temperatures have on dies CNM TECH is converting its die cooling system from water to oil. Oil maintains a warmer die temperature that contributes to a more uniform casting and extends die life, an important factor in part costs.

CNM TECH Die Casting company is adapting robotic controls to the operation of die casting machines. This permits a substantial increase in production rates, important in both controlling costs and meeting delivery requirements. It also allows us to use our people in ways which make better use of their skills and experience.

To lower production costs, CNM TECH Die Casting manufacturer has developed and patented, new, low volume, energy efficient aluminum melting furnaces. Since aluminum can be melted efficiently in small quantities, it allows the company to supply casting machines with different alloys of aluminum simultaneously. Casting machines don’t have to stand to wait for a large furnace to supply the proper alloy. Schedules aren’t built around what alloy is in the furnace.

Zinc Die Casting

For applications where high impact strength, low cost anZinc Die Castingd close dimensional limits are important design considerations, zinc die casting plays an important role. Zinc normally permits higher production rates than aluminum and parts can be designed with thinner cross-sections. The resulting parts are highly resistant to corrosion and receptive to a variety of beautiful finishes.

High rates of production and uniform quality are maintained by die casting machines with automatic extractors.

Vacuum Die Casting

Vacuum die casting is preferred by many casting buyers because it results in a less porous part. CNM TECH’s Vert-a-Cast machines, with a clamping force of 400 tons, are capable of producing castings automatically at a much faster pace than manually-operated horizontal machines.

Vacuum die casting, a CNM TECH capability for ten years, is often the only economical way to meet critical porosity specifications.

Maintenance, repair, changes and corrections on dies are accomplished promptly in CNM TECH’s fully-equipped tool and die shop.

Alloy materials are melted, fluxed and cleaned in the central furnace before being transferred to die casting equipment.

If you have any die casting requirement, you are welcome to send us your requirement for a quotation.

Die Casting Parts

Your High-Quality Source For Aluminum, Magnesium and Zinc Die Castings; Machined and Finished, Ready For Assembly.

Setting product quality as the company goal, CNM Die Casting has risen to the top of its industry during the past ten years.

Die casting buyers to look to CNM TECH to help reduce reject problems they have encountered with other component part suppliers. A manufacturer of natural gas valves experienced reject levels of up to 40% until they were cast by CNM TECH. Now, very few of their parts fail to meet a rigorous 100% testing level for pressure leaks.

Quality based on engineering experience

At CNM TECH Die Casting company, quality begins with experienced engineering assistance. Consultation on part design and aluminum alloy selection are part of the service. Sometimes minor changes in part design can increase production rates and eliminate potential quality problems. The end result is a better part at a lower unit cost.

To be sure finished die casting parts to meet alloy specifications, both incoming materials and finishDie Casting Manufacturered product samples are checked on the Jarrell-Ash spectrometer.

Quality that moves with production instead of just a final part check

Production starts after a final part design is accepted. Our quality control program then begins a series of checks to determine that the part has been produced within the specified tolerances. First, alloys are tested to make sure they meet our customer’s specifications. Then, statistical sampling during the casting and machining processes provides an early warning of manufacturing defects and helps to prevent the production of defective finished parts. Inspection frequencies can be predetermined by the job requirements to make certain that the parts you receive are parts you can use.

A Three Coordinate Measuring Machine (CMM) allows completed part dimensions to be checked against computer-stored specifications to assure that accuracy has been maintained throughout the entire production run. Fatigue testing for completed parts can also be carried out under simulated operating conditions if required by the customer.

Whether your specifications call for pressure tightness, critical dimensions and details, or freedom from subsurface discontinuities, CNM TECH quality assurance people have the equipment and training for the job.

A regular inspection program on casting and machining equipment helps us maintain close tolerances. Equipment that’s in top operating condition benefits our customers in both reduced costs and shorter lead times. In-plant maintenance personnel can quickly correct machine problems and smooth production flow.

Die Casting CompanyThis online catalogue will introduce you to our capabilities and give you a brief tour of our facility. Over 150 employees share our interest in providing on-time delivery of ready-for-assembly die casting parts and our objective of striving for the highest quality.

CNM TECH engineers are available for consultation at early design stages to help assure finished parts meet tolerance and quality requirements while making economical use of die casting processes.

The dimensional coordinate measuring machine is used to measure castings against specified tolerances.

Proven, rigid quality assurance techniques applied at CNM TECH Die Casting manufacturer can meet the most demanding industrial standards.

Metal casting services involve the shaping of free-flowing liquid metals through the use of dies, molds, or patterns.  Castings are generally roughly finished due to the nature of their production.  In many cases, additional finishing is required to remove burrs and other artefacts of the casting process.  Metal castings services are used to design a wide range of components and finished products.  Everything from simple nails and fasteners to engine blocks can be fabricated using metal casting services.  Common metal casting processes include sand casting, die casting, permanent mold casting, investment casting, centrifugal casting, and lost foam casting.

Sand Casting

Sand casting is used to make large parts (typically iron, but also bronze, brass, aluminum). Molten metal is poured into a mold cavity formed out of sand (natural or synthetic). Sand castings generally have a rough surface, sometimes with surface impurities and surface variations.

zinc Die Casting

zinc Die Casting

Die-casting includes a number of processes in which reusable dies or molds are used to produce casting.  The die contains an impression of the finished product together with it’s running, feeding and venting systems.  The die is capable of a regular cycle and of (quickly) dissipating the heat of the metal poured into it.  Once the liquid metal has cooled sufficiently, the mold is opened and the casting can be removed and finished.

Permanent Mold Casting

In permanent mold casting, molten metal is poured into cast iron molds, coated with a ceramic mold wash. Cores can be a metal, sand, sand shell, or other materials. When completed, the molds are opened and the castings are ejected.

 

Investment casting services involve molding patterns by the injection of a special wax into a metal die.  The patterns are assembled into a cluster around a wax runner system. The ‘tree’ of patterns is then coated with 8-10 layers of refractory material. The assembly is heated to remove the wax.  The hot mold is cast, and when cool, the mold material is removed by impact, vibration, grit blasting, high-pressure water blasting or chemical dissolution leaving the castings, which are then removed from the runner system.

Centrifugal casting

Centrifugal casting services are used to produce castings that are cylindrical in shape.  In centrifugal casting, a permanent mold is rotated about its axis at high speeds as the molten metal is poured. The molten metal is centrifugally thrown towards the inside mold wall, where it solidifies. The casting is usually a fine grain casting with a very fine-grained outer diameter, which is resistant to atmospheric corrosion, a typical need with pipes. The inside diameter has more impurities and inclusions, which can be machined away.

magnesium die casting

magnesium die casting

Lost foam casting

Lost foam casting (LFC) is metal casting services that use foam filled patterns to produce castings.  Foam is injected into a pattern, filling all areas, leaving no cavities.  When molten metal is injected into the pattern, the foam is burned off allowing the casting to take shape.

Die casting

Die casting and metal casting includes a number of processes in which reusable dies or molds are used to produce casting. The die is capable of a regular cycle and of (quickly) dissipating the heat of the metal poured into it. Once the liquid metal has cooled sufficiently, the mold or is opened and the casting can be removed and finished.

 

In the die casting process, molten metal is injected under pressure into a reusable mold or die. The die contains an impression of the casting together with it’s running, feeding and venting systems. The die is capable of a regular cycle and of (quickly) dissipating the heat of the metal poured into them. Once the liquid metal has cooled sufficiently, the mold or is opened and the metal casting can be removed and finished.

high pressure die casting

The high pressure die casting process is the most widely used, representing about 50% of all light alloy casting production. Low pressure die casting currently accounts for about 20% of production and its use is increasing. Gravity die casting accounts for the rest, with the exception of a small but growing contribution from the recently introduced vacuum die casting and squeeze casting process. the design of low pressure and gravity die casting dies for improved die filling, optimized solidification pattern and maximum yield. Gravity die-casting is suitable for mass production and for fully mechanized casting. Low-pressure die casting is especially suited to

Aluminum die casting

Aluminum Die Casting

the production of components that are symmetric about an axis of rotation. Light automotive wheels are normally manufactured by this technique.

Die casting metals can vary widely, and different die casting companies may have the ability to work with anyone or number of them. Some of the most common metal casting types include aluminum die casting, brass die casting, lead die casting (the most popular for model die casting), magnesium die casting, and zinc die casting.

Hope all of that information is enough for your reference, but if you want to know more information, you are welcome to contact us by phone or email.

A380 Aluminum Die Casting

Since the year of its inception in 1999, CNM Die Casting has consistently endeavoured for achieving sustained excellence in every sphere of its business. Though we started as a supplier of zinc die casting, we have diversified to aluminum die casting, recently. And this has borne rich dividends both in terms of customer satisfaction and company revenue.

Aluminum Die Casting That Provides Quality and Performance

We at CNM Die Casting’s aluminum department have a reputation of offering our customers the exact die casting aluminum specifications. This has been possible due to our state of technology studio, which is equipped with 21 machines ranging in clamping tonnage from 400 to 1200 tons. We cast aluminum castings up to 45 pounds in 360 alloys and up to 13 pounds in 380 alloys. Our aluminum and zinc departments use central melt furnaces and an efficient launder system to transfer molten metal safely and with the consistency of temperature necessary for process control. To complement our launder system, we have fully automated cells which assure shot to shot consistency like:

  • Aluminum Capacity, 10g to 125kg
  • Aluminum Die Cast Dies weight up to 30 Tons
  • Tymac Process Controls
  • Vacuum Assist
  • 4000kg. To 135,000kg. Furnace Capacity
  • ADC 12, 360, 380 Material, or any other special material base on customer requirement

Aluminum Die Casting Equipment That Delivers Excellence

Die casting aluminum is our forte and our cold-chamber die casting machines are typically used to conventionally die cast components using aluminum alloys.

In order to achieve high productivity and good dimensional accuracy, we at GC Die Casting are furnished with

  • 250 Ton Die Casting Machines

  • 400 Ton Die Casting Machines
  • 600 Ton Die Casting Machines
  • 800 Ton Die Casting Machines
  • 1000 Ton Die Casting Machines
  • 1250 Ton Die Casting Machines
  • 1650 Ton Die Casting Machines

A380 aluminum die casting is our speciality that provides an excellent combination of material properties and ease of production.

Aluminum Die Casting Equipment That Generates Cost Effectiveness

Over the last few years, St Clair die casting has offered its services of aluminum die casting components for a wide range of markets. This includes industry sectors like an appliance, automotive, electronics, and instruments etc. And the demand is only growing higher every day, the reason for this burgeoning need is our quality services coupled with prices that are best in the industry. Order with us to believe us! And we assure you long term dependability and quality.

To know more about our products and services, you can call our Customer Service by +86 3388 9978 or send us an email by sales@thediecasting.com

Die casting is a manufacturing process for producing accurately dimension, sharply defined, smooth or textured-surface metal parts. It is accomplished by forcing molten metal under high pressure into reusable metal dies. The process is often described as the shortest distance between raw material and finished product. The term, “die casting,” is also used to describe the finished part.
The term “gravity die casting” refers to castings made in metal molds under a gravity head. It is known as permanent mold casting in the U.S.A. and Canada. What we call “die casting” here is known as “high pressure die casting” in Europe.

HOW ARE DIE CASTINGS PRODUCED?

First, a steel mold capable of producing tens of thousands of castings in rapid succession must be made in at least two sections to permit removal of castings. These sections are mounted securely in a machine and are arranged so that one is stationary (fixed die half) while the other is moveable (injector die half). To begin the casting cycle, the two die halves are clamped tightly together by the die casting machine. Molten metal is injected into the die cavity where it solidifies quickly. The die halves are drawn apart and the casting is ejected. Die casting dies can be simple or complex, having moveable slides, cores, or other sections depending on the complexity of the casting.
The complete cycle of the die casting process is by far the fastest known for producing precise non-ferrous metal parts. This is in marked contrast to sand casting which requires a new sand mold for each casting. While the permanent mold process uses iron or steel molds instead of sand, it is considerably slower, and not as precise as die casting.

TYPES OF MACHINES FOR DIE CASTING

Regardless of the type of machine used, it is essential that die halves, cores and/or other moveable sections be securely locked in place during the casting cycle. Generally, the clamping force of the machine is governed by (a) the projected surface area of the casting (measured at the die parting line) and (b) the pressure used to inject metal into the die. Most machines use toggle type mechanisms actuated by hydraulic cylinders (sometimes air pressure) to achieve locking. Others use direct acting hydraulic pressure. Safety interlock systems are used to prevent the die from opening during the casting cycles.
Die casting machines, large or small, very fundamentally only in the method used to inject molten metal into the die. These are classified and described as either hot or cold chamber die casting machines.What is Die casting

HOT CHAMBER MACHINES
Hot chamber machines (Fig.1) are used primarily for zinc, and low melting point alloys which do not readily attack and erode metal pots, cylinders and plungers. Advanced technology and development of new, higher temperature materials have extended the use of this equipment for magnesium alloy die casting.
Figure 1: Hot Chamber Machine. Diagram illustrates the plunger mechanism which is submerged in molten metal. Modern machines are hydraulically operated and equipped with automatic cycling controls and safety devices.
In the hot chamber machine, the injection mechanism is immersed in molten metal in a furnace attached to the machine. As the plunger is raised, a port opens allowing molten metal to fill the cylinder. As the plunger moves downward sealing the port, it forces molten metal through the gooseneck and nozzle into the die. After the metal has solidified, the plunger is withdrawn, the die opens, and the resulting casting is ejected.
Hot chamber machines are rapid in operation. Cycle times vary from less than one second for small components weighing less than one ounce to thirty seconds for a casting of several pounds. Dies are filled quickly (normally between five and forty milliseconds) and metal is injected at high pressures (1,500 to over 4,500 psi). Nevertheless, modern technology gives close control over these values, thus producing castings with fine detail, close tolerances and high strength.

COLD CHAMBER MACHINES


Cold chamber machines (Fig. 2) differ from hot chamber machines primarily in one respect; the injection plunger and cylinder are not submerged in molten metal. The molten metal is poured into a “cold chamber” through a port or pouring slot by a hand or automatic ladle. A hydraulically operated plunger, advancing forward, seals the port forcing the metal into the locked die at high pressures. Injection pressures range from 3,000 to over 10,000 psi for both aluminum and magnesium alloys, and from 6,000 to over 15,000 psi for copper base alloys.

Die castingFigure 2: Cold Chamber Machine. Diagram illustrates die, cold chamber and horizontal ram or plunger (in charging position).
Die casting provides complex shapes within closer tolerances than many other mass production processes. In a cold chamber machine, more molten metal is poured into the chamber that is needed to fill the die cavity. This helps sustain sufficient pressure to pack the cavity solidly with casting alloy. Excess metal is ejected along with the casting and is part of the complete shot.
Operation of a “cold chamber” machine is a little slower than a “hot chamber” machine because of the ladling operation. A cold chamber machine is used for high melting point die casting alloys because plunger and cylinder assemblies are less subject to attack since they are not submerged in molten metal.
CASTING DIES AND THEIR CONSTRUCTION


Die casting dies (Fig. 3) are made of alloy tool steels in at least two sections called fixed die half and ejector die half. The fixed die half is mounted on the side toward the molten metal injection system. The ejector die half, to which the die casting adheres, and from which it is ejected when the die is opened, is mounted on the moveable platen of the machine.

The fixed die half of the die is designed to contain the sprue hole through which molten metal enters the die. The ejector half usually contains the runners (passageways) and gates (inlets) which route molten metal to the cavity (or cavities) of the die. The ejector half is also connected to an ejector box which houses the mechanism for ejecting the casting from the die. Ejection occurs when pins connected to the ejector plate move forward to force the casting from the cavity. This usually occurs as part of the opening stroke of the machine. Placement of ejector pins must be carefully arranged so force placed upon the casting during ejection will not cause deformation. Return pins attached to the ejector plate return this plate to its casting position as the die closes.
Fixed and moveable cores are often used in dies. If fixed, the core axis must be parallel to the direction of die casting mold opening. If moveable, they are often attached to core slides. Should the side of a die casting design require a depression, the die can be made with one or more slides to obtain the desired result without affecting ejection of the casting from the die cavity. All moveable slides and cores must be carefully fitted, and have the ability to be securely locked into position during the casting cycle. Otherwise, molten metal could be forced into their slideways causing a disruption of operations. Although slides and cores add to the complexity and cost of die construction, they make it possible to produce die castings in a wide variety of configurations, and usually more economically than any other metalworking process.
TYPES OF DIES


Dies are classified as: single cavity, multiple cavities, combination and unit dies (Figures 4-A to 4-D).

A single cavity die requires no explanation. Multiple cavity dies have several cavities which are all identical. If a die has cavities of different shapes, it’s called a combination or family die. A combination of die is used to produce several parts for an assembly. For simple parts, unit dies might be used to effect tooling and production economies. Several parts for an assembly, or for different customers, might be cast at the same time with unit dies. One or more unit dies are assembled in a common holder and connected by runners to a common opening or sprue hole. This permits simultaneous filling of all cavities.

ADVANTAGES OF DIE CASTING


Die casting component parts, decorative trim, and/or finished products offer many features, advantages and benefits to those who specify this manufacturing process.zinc Die Casting

  1. Die castings are produced at high rates of production. Little or no machining is required.
  2. Die castings can be produced with thinner walls than those obtainable by other casting methods … and much stronger than plastic injection moldings with the same dimensions.
  3. Die casting provide parts which are durable, dimensionally stable, and have the feel and appearance of quality.
  4. Die casting dies can produce thousands of identical castings within specified tolerances before additional tooling may be required.
  5. Zinc die castings can be easily plated or finished with a minimum of surface preparation.
  6. Die castings can be produced with surfaces simulating a wide variety of textures.
  7. Die-cast surfaces, as cast, are smoother than most other forms of casting.
  8. Holes in die castings can be cored and made to tap drill sizes.
  9. External threads on parts can be readily die cast.
  10. Die castings provide integral fastening elements, such as bosses and studs, which can result in assembly economies.
  11. Inserts of other metals and some non-metals can be die cast in place.
  12. Corrosion resistance of die casting alloys rates from good to high.
  13. Die castings are monolithic. They combine many functions in one, complex shaped part. Because die castings do not consist of separate parts, welded or fastened together, the strength is that of the material, not that of threads or welds, etc.
  14. Die Casting process can produce aluminum die casting, magnesium die casing, zinc die casting, brass die casting , lead casting and so on, and all of those can be easily massive produced.

Die casting is an efficient, economical process which, when used to its maximum potential, replaces assemblies of a variety of parts produced by various manufacturing processes at significant savings in cost and labour.
COMPARISONS WITH OTHER PRODUCTS


Plastics injection molding Parts


Compared with plastic injection molding Parts, die castings are the stronger, stiffer, more stable dimension, more heat resistant, and are far superior to plastics on a properties/cost basis. They help prevent radio frequency and electromagnetic emissions. For chrome plating, die castings are much superior to plastic. Die castings have a high degree of permanence under load when compared to plastics, are completely resistant to ultra-violet rays, weathering, and stress-cracking in the presence of various reagents. Manufacturing cycles for producing die castings are much faster than for plastic injection moldings. Plastics, however, may be cheaper on a unit volume basis, have colour inherent properties which tend to eliminate finishing, are temperature sensitive, and are good electrical insulators.

Sand castings


Compared with sand castings, die castings require much less machining; can be made with thinner walls; can have all or nearly all holes cored to size; can be held within much closer dimensional limits; are produced more rapidly in dies which make thousands of die castings without replacement; do not require new cores for each casting; are easily provided with inserts die cast in place; have smoother surfaces and involve much less labor cost per casting. Sand castings, on the other hand, can be made from ferrous metals and from many non-ferrous alloys not suitable for die casting. Shapes not producible by die casting are available in sand castings; maximum size can be greater; tooling cost is often less and small quantities can be produced more economically. you can check more sand aluminium casting

Die-casting-parts
Permanent mold castings


Compared with permanent mold castings, die castings can be made to closer dimensional limits and with thinner sections; holes can be cored; are produced at higher rates with less manual labour; have smoother surfaces and usually cost less per die casting. Permanent mold casting involves somewhat lower tooling costs; can be made with sand cores yielding shapes not available in die casting.
Forgings
Compared with forgings, die castings can be made more complex in shape and have shaped not forgeable; can have thinner sections; be held to closer dimensions and have coring not feasible in forgings. Forgings, however, are denser and stronger than die castings; have properties of wrought alloys; can be produced in ferrous and other metals and in sizes not suitable for die castings.
Stamping
Compared with stamping, one die casting can often replace several parts. Die castings frequently require fewer assembly operations; can be held within closer dimensional limits; can have almost any desired variation in section thickness; involve less waste in scrap; are producible in more complex shapes and can be made in shapes not producible in stamped forms. Stamping, on the other hand, have properties of wrought metals; can be made in steel and in alloys not suitable for die casting; in their simpler forms, are produced more rapidly; and may weigh less than die castings.
Screw machine products
Compared with screw machine products, die castings are often produced more rapidly; involve much less waste in scrap; can be made in shapes difficult or impossible to produce from the bar or tubular stock, and may require fewer operations. On the other hand, screw machine products can be made from steel and alloys which cannot be die cast; they have the properties of wrought metals, and they require less tooling expense.