Contract Manufacturing of Metal Casting
Metal casting services involves the shaping of free-flowing liquid metals through the use of dies, molds, or patterns. 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.
Contract Manufacturing of 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. The lowest cost method for making bulk parts which do not require tight tolerances. Sand castings generally have a rough surface, sometimes with surface impurities and surface variations. Applications include bases, housings, and brackets. More precise dimensions can be achieved by a secondary machining operation.
Contract Manufacturing of Die Casting
Die casting is also called pressurized 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 its 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. Melted metal is pumped into a cavity using pressure. The pressure gives the finished part a more homogeneous microstructure, a better surface finish and more precise dimensions. Because of the high pressure, highly intricate structures can be achieved with zero or minor secondary machining. For high volume parts, die casting can produce huge cost savings.
Contract Manufacturing of Permanent Mold Casting
Similar to sand casting in principle, permanent mold casting method employs a hard mold. In permanent mold casting, molten metal is poured into cast iron molds, coated with a ceramic mold wash. Cores can be metal, sand, sand shell, or other materials. When completed, the molds are opened and the castings are ejected. With only a slightly higher mold cost than sand casting, this process achieves superior tolerances and surface finishes.
Contract Manufacturing of Investment Casting
Investment casting services involves molding patterns by the injection of a special wax into a metal die. Investment castings and sand castings are available in steel, alloy steel and stainless steel grades. The method uses heat-disposable wax or plastic patterns, which are surrounded by refractory material, to form a monolithic mold. The patterns are assembled into a cluster around a wax runner system. The 'tree' of patterns is then coated with 8-10 layers of a 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. The castings represent exact duplicates of the patterns. Following a light grinding, buffing, or other secondary finishing operation, the castings are inspected and shipped to the customer.
Contract Manufacturing: Forging
There are several processes used to create forgings. To create forging there are various processes. All of them involve shaping metal by plastic deformation. The common type of forging process is impression die forging, precision forging. The other forging processes are open die forging, ring rolling, extrusion and piercing .The temperature and processes for various methods of forging differ significantly. Forgings can be created using metal that is either cold, warm or hot, depending on the requirements of the finished product.
Closed die forgings and rolled ring forgings are being produced in carbon, alloy and stainless steel grades. In Open Die Forging the metal being shaped during open die forging is not completely confined during the process, which derives the name open die forging. Open die forging uses hammers and presses to shape metal parts. The open die forging process allows for some irregularities between forgings. The metal is usually rough machined and then finish machined to achieve final dimensions.
In impression die forging, two dies are brought together, squeezing the metal causing it to fill the die impression. Depending on the design, metal can be allowed to flow outside of the dies or can be allotted no escape. The impression die forging process usually requires one hit through a die cavity for the metal.
Rolled ring forgings are produced from carbon, alloy and stainless steel grades. Ring rolling is a highly engineered process resulting in seamless rings or forgings.
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