Die Casting Design

Die-casting can be done using a cold chamber or hot chamber process.

1. In a cold chamber process, the molten metal is ladled into the cold chamber for each shot. There is less time exposure of the melt to the plunger walls or the plunger. This is particularly useful for metals such as Aluminum, and Copper (and its alloys) that alloy easily with Iron at the higher temperatures.

2. In a hot chamber process, the pressure chamber is connected to the die cavity is immersed permanently in the molten metal. The inlet port of the pressurizing cylinder is uncovered as the plunger moves to the open (unpressurized) position. This allows a new charge of molten metal to fill the cavity and thus can fill the cavity faster than the cold chamber process. The hot chamber process is used for metals of low melting point and high fluidity such as tin, zinc, and lead that tend not to alloy easily with steel at their melt temperatures. die casting, aluminum die casting, aluminum casting, ADC-12 die casting, automotive die casting part, motorcycles spare part, aluminum pressure die casting

Automotive die casting
Automotive die casting

3. Die casting molds (called dies in the industry) tend to be expensive as they are made from hardened steel-also the cycle time for building these tend to belong. Also, the stronger and harder metals such as iron and steel cannot be die-cast

Aluminum die casting process introduction

Though the term die casting can refer to any kind of casting using a die such as gravity die casting or low pressure die casting, yet here die casting only refer to high pressure die casting. Aluminum die casting is a process of casting Aluminum alloy under pressure, can produce precision parts in high volume at low costs. There are two processes of aluminum die-casting namely hot chamber die casting and cold chamber die casting. Parison die casting introduced cold chamber die casting process from1980’s. Now the die casting machines which Parison die casting is applying are cold chamber die casting machines.

Illustration of cold chamber die casting process

In a cold chamber die casting process, the molten aluminum alloy is ladled into the cold chamber for each shot. There is less time exposure of the melted alloy to the plunger walls or the plunger. This is particularly useful for aluminum alloy that alloys easily with Iron at the higher temperatures.

After the molten aluminum alloy is ladled into the cold chamber, the piston will inject it into the cavity of the die casting mold through three different pressure phrases. The pressured molten aluminum alloy gets in sequence through spure system, running system, and gate system into the cavity of the die casting mold.

The filled cavity with affection of cooling system shapes the desired aluminum die casting products. Then the moving die moves away from the fix die, while the ejectors push out the casting.

Advantage of aluminum die casting process

A.high volume but low cost Compared with aluminum sand casting and gravity casting, aluminum die casting can produce precision parts in high volume at low costs.

Aluminium die casting
Aluminium die casting

B.good surface finish and good dimensional accuracy Aluminum die casting generally has good surface finish and good dimensional accuracy. For many parts, post-machining can be totally eliminated, or very light machining may be required to bring dimensions to size.

The disadvantage of aluminum die casting process

A.high cost of die casting mold The cost of tooling of die casting is much more expensive than those of sand casting, gravity casting, and investment casting.

B.high porosity Though the porosity of die casting can be adjusted by using much higher pressure with a much larger and heavier mold, the porosity can not be avoided and is much more than that is of low-pressure casting and gravity casting. Furthermore, porosity leads die casting parts to be not suitable for heat treatment. Thus the consistency can not be compared with gravity castings.

FAQ’s of aluminum die casting process

what is aluminum die casting process?

what is the cold chamber die casting process?

what is the difference between cold chamber and hot chamber die casting process?

What is the application of die casting process?

what kinds of metal can be applied in die casting process?

why is the cold chamber die casting process preferable for aluminum casting rather than hot chamber die casting process?

what is the application of die casting products?

what kinds of post-treatments can be available for aluminum die casting products?

what is the difference between aluminum high-pressure die casting and low pressure die casting?

what is gravity die casting? Is it the same as high pressure die casting process?

Metal Casting

AQL Acceptable Quality Level. A quality level established on a prearranged system of inspection using samples selected at random.

As-cast condition Casting without subsequent heat treatment.

Backing sand The bulk of the sand in the flask. The sand compacted on top of the facing sand that covers the pattern.

Binder The bonding agent used as an additive to mold or core sand to impart strength or plasticity in a “green” or dry state. Read more

Cast Copper Alloys

A Primer on Selecting Cast Copper Alloys

Traditionally, cast copper alloys were classified by a variety of systems including the ASTM letter-number designation based on nominal composition, by trade names, and by descriptive terms such as “ounce metal,” “Navy M” and so forth. However, with technological developments, new alloys were produced and existing alloys modified, making the old designation systems inadequate and misleading.

A new system was developed based on a precise description of the composition range for each alloy, which is now the accepted alloy designation system used in North America for cast copper and copper alloy products. Originally developed as a three digit system by the copper and brass industry, the designations have now been expanded to five digits that follow a prefix letter “C,” and have been made part of the Unified Numbering System (UNS) for Metals and Alloys. The UNS is managed jointly by the American Society for Testing and Materials, and the Society of Automotive Engineers. Read more

Aluminium Casting

A Basic Guide to Choosing Aluminum Casting Alloys Part 2

Alloys 319.0, A319.0, B319.0 & 320.0
Alloys 319.0 and A319.0 exhibit very good castability, weldability, pressure tightness and moderate strength. They are very stable alloys (i.e., their good casting and mechanical properties are not affected seriously by fluctuations in the impurity content). Alloys B319.0 and 320.0 show higher strength and hardness than 319.0 and A319.0 and are generally used with the permanent mold casting process. Characteristics other than strength and hardness are similar to those of 319.0 and A319.0. Read more

Aluminum Casting Alloys

The mechanical properties of alumi- num casting alloys are obtainable only if the chemical and heat treating specifications are followed carefully. It should be noted that the properties obtained from one particular combination of casting alloy, foundry practice and thermal treatment may not necessarily be identical to those achieved with the same alloy in a different foundry or with a different thermal treating source. In all aluminum casting alloys, the percentages of alloying elements and impurities must be controlled carefully. If they are not, characteristics such as soundness, machinability, corrosion resistance and conductivity are affected adversely. Read more