All About Squeeze Casting|Echofast

Squeeze casting is an emerging metal forming process that has the characteristics of casting and is similar to die forging. This process is capable of producing components with excellent strength, which make it an increasingly popular casting method. However, it also has some disadvantages that should be taken into consideration. This article will discuss the basics of squeeze casting, including definition, types, materials, benefits and drawbacks.

What Is Squeeze Casting?

Squeeze casting, also known as liquid metal forging, is a manufacturing process that combines casting and forging. It starts by pouring the molten metal into a heated die. Then, the metal begins to solidify, and the upper die is closed. With the pressure applied, the casting cavities are completely filled with metal, which guarantees accurate shape, minimal shrinkage and remarkable mechanical properties. The process can be used to cast various metals. Aluminum and magnesium alloys are most commonly used for the procedure.

Types of Squeeze Casting

Squeeze casting can be divided into two types, and they are indirect squeeze casting and direct squeeze casting. Both processes can produce squeeze cast parts with great strength and durability, and reduce 35% of the weight of most metals.

1.Indirect Squeeze Casting

Indirect squeeze casting is like die casting since the chamber used is similar. The process involves introducing molten metal into a shot sleeve. The melt is then injected into the die through relatively large gates at a low velocity of less than 0.5 m/s. The metal is solidified with the high pressure applied, which ranges from 55 to 300 MPa. Indirect squeeze casting contributes to preventing defects and greater tensile strength of the final part due to the better control of solidification.

2.Direct Squeeze Casting

In direct squeeze casting, the molten metal is poured into the bottom half of a heated, lubricated die. The upper half is then closed, which results in complete filling. Pressure is applied to the entire cavity until the component solidifies. The process resembles metal forging process. It offers better heat transfer, producing adequate structures. The internal quality of direct squeeze casting is higher than that of indirect squeeze casting.

Process of Squeeze casting

The process of squeeze casting is performed on a special squeeze casting machine or an ordinary hydraulic press. It is generally divided into the following steps.

1.Mold preparation. It includes cleaning and spraying the mold, extrusion barrel and extrusion punch, and returning them to the ready position.

2.Pouring Inject liquid (or semi-solid) metal into the concave shape or barrel.

3.Close the mold. Close and lock the mold, and put the barrel and punch into the position to be extruded.

4.Use a squeeze punch to push the liquid (semi-solid) metal into the cavity and continue to maintain pressure until it is completely solidified.

5.Open the mold and push out the casting.

Metals Used in Squeeze Casting

Squeeze casting can be used to make parts using both ferrous metals and non-ferrous metals. Listed below are some common metals used in squeeze casting.

1.Zinc

2.Magnesium

3.Aluminum

4.Copper Alloys

Applications of Squeeze Casting

Squeeze casting can create complex and high-quality castings with superior mechanical qualities and dimensional accuracy. Due to this benefit, it is widely used for metal part production in automotive, marine, machinery, defense, and other industries. Typical applications include:

Automotive

Aluminum chassis frames
Aluminum brackets
Aluminum nodes
Pistons
Aluminum steering knuckles
Aluminum automotive wheels
Horizontal blocks for engines

Marine

The tiny turbine blades and propellers for ships

Machinery

Steel bevel gears for machinery
Pistons for internal combustion engines
Bronze and brass gear blanks
Brass pipes
Stainless steel blades
Alloy discs

Defense

Military weapons like iron mortar shells

Aerospace

Critical aircraft structural elements

Advantages of Squeeze Casting

Squeeze casting offers some advantages, including:

1.Low porosity

The metal parts created by squeeze casting have low porosity and high density due to the production of the minimal amount of air bubbles.

2.Higher dimensional accuracy and clearer appearance outlines

Squeeze-cast parts boast higher dimensional accuracy, better surface texture, and clearer appearance outlines with pressure applied.

3.Lower labor cost

Since that squeeze casting is performed on a press or squeeze casting machine, it facilitates the realization of mechanization and automation. This greatly reduces human labor intensity and improves the production environment of the workshop.

4.Adapt to more materials

This process is suitable for forming various non-ferrous alloys and other ferrous metals, as well as metal-based composite materials.There is almost no material wasted in the process as well.

5.Excellent mechanical properties

The process produces parts with excellent mechanical properties, such as strength and ductility.

Disadvantages of Squeeze Casting

Listed below are some disadvantages of squeeze casting :

1.Not suitable for the production of thin-walled and complex parts

This is because the castings are fed through pressure transmission and the condensation speed is fast.

2.High cost

The cost is high due to the specialized equipment and tooling requirements.

3.High machining requirement

High machining is required for precise tolerances , which is one of the common limitations of squeeze casting.

FAQs

1.What is the difference between squeeze casting and high-pressure die casting?

The application of pressure.The pressure applied in squeeze casting is lower than that of high-pressure die casting.

2.What is the alternative for squeeze casting ?

High-pressure die casting. It is a metal casting process in which the molten metal is forced under high pressure into a mold cavity and solidified to obtain the desired parts.

3.What determines time duration in squeeze casting ?

The casting configuration, alloy type and heat transfer conditions.

4.Why does the die temperature have to be monitored within close limits?

Because too low preheating temperature of die may lead to quick solidification and cold laps in the castings, and too high temperature may result in the surface defects and metallization (casting and die welding).