During casting, a manufacturer pours a liquid, usually molten metal alloys or plastic, into a mold. As it solidifies, the material assumes the shape of the mold cavity. Casting utilizes either temporary or longer-lasting molds to create objects in a variety of sizes and shapes. It usually allows manufacturers to reproduce surface details.
Die casting developed as a casting methodology during the Industrial Revolution. It provides a way to create cast products in high volumes in automated mass production environments using die casting machines. Modern squeeze casting has arisen as a modified form of die casting.
About Squeeze Casting
Squeeze casting has grown in popularity in recent years because it enables manufacturers to produce high volumes of metal castings which display low porosity. During many other casting processes, the pouring of metals into molds or dies will entrap air bubbles; the escaping gases create pores on the surface of work pieces. In the worst case scenario, the solidifying molten metal retains entrapped pockets of tiny bubbles or gas within metal parts. High porosity provides grounds for part rejection by customers. The use of squeeze casting enables metal part manufacturers to overcome many problems associated with porosity.
Squeeze Casting Process
Squeeze casting involves a modification of the conventional die casting process. Die casting today creates many low-cost, widely used consumer items. For example, manufacturers often generate small aluminum or zinc alloy metal parts using die casting.
While a manufacturer performs die casting at a rapid pace by injecting molten metal into a two-part die in a die casting machine through gated channels, during direct squeeze casting the manufacturer sends molten metal at a slower rate only into the lower half of the die. The manufacturer will usually heat the lower die in advance of pouring in order to help keep the metal in a liquid state longer and prevent premature solidification. Molten metal sometimes flows into the lower die.
The closure of the upper die then precedes the application of intense pressure (in a process somewhat analogous to the forging performed by a blacksmith). In this way, squeeze casting helps produce more finely grained, compressed metal components. It also permits manufacturers to reproduce surface details in squeeze castings.
Types of Squeeze Casting
During the production of metal parts through squeeze casting, manufacturers have developed two broad types of low porosity casting: direct squeeze casting (also known as liquid metal forging) and indirect squeeze casting.
During indirect squeeze casting, a manufacturer employs an automatic pump to inject a measured plug of molten metal into the bottom of a squeeze casting die through broad gates. This step occurs prior to the application of intense pressure. This type of casting may require a significant capital investment in equipment, since it significantly modifies the operation of conventional die casting machines. A computer controlled manufacturing environment may assist this manufacturing process by offering the manufacturer greater control over the speed of production.
During both types of casting, manufacturers may perform squeeze casting operations in vacuum-controlled environments in some settings. Both the intended use of the metal parts created through direct or indirect squeeze casting and the properties of the raw materials employed during production sometimes influence the choice of manufacturing technologies. Both squeeze casting methods have increased in popularity in recent years because these techniques provide a way to minimize the porosity of castings.
Squeeze Casting: Materials And Applications
Many manufacturers today seek information concerning squeeze casting materials and applications. Bunty LLC assists customers in this situation. We offer a full range of high quality squeeze casting services:
The raw materials employed in squeeze casting run the gamut from ferrous metal alloys to zinc, aluminum and magnesium alloys. This casting process proves useful when companies seek to create high quality low porosity castings using lightweight metal alloys. It does require an investment in die casting technology capable of accommodating slower die filling.
Since dies fill more slowly during this type of casting, the hardening of the metal prior to the completion of the pouring process sometimes challenges manufacturers. A number of companies offer proprietary lubricant products to assist with squeeze casting. In addition to raw materials, manufacturers who produce these types of castings invest in specialized die casting equipment and lubricants.
Manufacturers have discovered numerous applications for squeeze castings in a variety of economic sectors. This method of casting has achieved popularity as a way to create high quality automotive parts, including chassis frames and other components sometimes containing lighter weight metals. It also offers a means of creating boat propellers and small turbine blades.
Advantages of Squeeze Casting
As a form of casting, squeeze casting supplies some important advantages.
- This technique permits manufacturers to create products with fewer entrapped air bubbles than most other types of casting. The low porosity contributes to higher quality work pieces. Squeeze castings as a result may command higher market prices.
- Metal parts created with the assistance of squeeze casting resist shrinkage better than many other casting processes. Manufacturers who rely upon this technique may enjoy fewer rejected castings due to shrinkage, thus potentially minimizing waste. Squeeze casting may represent the most economical form of casting under some circumstances.
- The capability to cast both ferrous alloys and non-ferrous materials offers numerous manufacturing benefits. Squeeze casting reportedly permits manufacturers to utilize composite fibers without suffering a loss in work piece quality or fine detail. This versatile form of casting holds appeal for innovative parts producers. Companies can use squeeze casting to create many products.