Research and development in gravity casting has taken animportant step in making metal products a part of our day to day lives. Theproducts used in homes, aircrafts, artifacts, automobiles have machinery parts become moredurable and less expensive. Cast alloy parts are formed by melting the alloyand then pouring it in a mold under heavy pressure or vacuum. Gravity castingis also known as vacuum casting. It is a technique in which large diameterfilaments are used with adequate separation. This ensures that no clusters areformed and also good metal wetting of the fiber is guaranteed. This techniquewas first used in 1970. The gravity casting method has advantages like costeffective, good quality, and process control over other casting techniques.

Gravity casting is done in ceramic molds, sand, permanentcasting and also in investment or lost wax casting. The gravity casting processwas started with common steel after successful implementation it was furthertried on heat resistance super alloys. With recent development and with morerefined methods today even titanium alloys are being cast using the gravitycasting method and using ceramic crucibles. The use of desired mold designs andalso specially made unique designs enable a reduction in the metal cast toyield the given part. This also helps in reducing the amount of energy that isused in making such casting articles.

With new developments, today even computerized control ofthe vacuum pressure and rate is possible. This enables the user to control thefilling rate. This makes casting of high quality metals like and viscous metalslike metal matrix and composites of aluminum casting possible. This gravitycasting method is used to produce casting worth of more than $200 million. Theindustry is expected to grow rapidly in the coming years due to the increase inproduction of automotive exhaust manifolds in stainless steel.

The first ever commercial use of this computerizedtechnology, was made by Howmet Industries of Whitehall, Michigan. They usedthis technology to precisely cast and design turbine blades used in aircrafts.This technology is also being used by Ford Motors to develop and improve thecasting process of light truck and automobile engine blocks.

Today, metal parts fabricated using gravity casting methodis being used in 90 per – cent of all durable goods. Goods like stoves, washingmachine, automobiles, refrigerators, lawn mowers, cars and even boats. Manyother articles like badminton rackets, tennis rackets, and even football studsare made by using light weight metals which are gravity casting method. Thisgravity casting method has been used to develop metal alloy parts, which areused for the auto and airline industries, which is said to make vehicleslighter though much stronger and extremely efficient.

Alloys like ferric cast metals, casting grade iron and steelare typical metals that are used for gravity casting. Also die cast grade zinccan be cast using gravity casting method. Also other raw materials like sand, spinor plaster are used. Aluminum is also used, but it is very difficult to gravitycast aluminum a lot of care needs to be taken and proper pressure should beapplied to obtain the desired shape and effect. 

Castingmolds are an essential part of the metal casting process as it will be used toshape the final result. Nearly all metal casting methods will use some type ofmold. The standard mold will consist of a cope and drag that when together iscalled a flask. The mold itself can be constructed of several materialsdepending upon the casting method.Most molds will be made from latex, fiberglass, sand, and even metal. Sandmolds are the most popular since Sand Casting is commonly used in small homefoundries. In Permanent Mold Casting, the mold is created from metal. Mostmolds can be used over and over again, but not all of them. Certainly the metalmolds can be used multiple times without loosing any quality from the finishedproduct. However, molds created using sand or other materials will not have avery long shelf life. This is not generally seen as a huge problem just aminor annoyance since mold making is relatively cheap and easy. No matter what material the mold is made from, the basic construction is prettymuch the same. The molding box is called the flask which has a cope, the top,and drag, the bottom.  You will then fill the flask with the moldingmaterial and then place the original into the mold. So, if you want to cast atiny metal elephant, you will place an original of the elephant usually madefrom clay, wax, wood, or even metal into the drag of the flask. If this is donein sand you will ram the flask until the sand is packed tightly around theoriginal. The top of the flask, the cope is then placed on and more moldingmaterial poured in. The entire flask is then rammed or vibrated making sureeverything is packed in nice and tight.When the Metal Casting Manufacturers molding material is dry, you will remove the flask and carefully splitthe mold to retrieve the original, in this case the tiny elephant. Now, if youwant to make sure that there are some empty spaces in the cast to be finishedthen you will place cores into the mold. The cores are made of sand or wax.The type of mold used depends heavily on the type of casting, alloy, andcomplexity of the pattern to be cast. Metal molds have little use in smallfoundries unless you plan on casting a lot of tiny metal elephants.In some cases, pre-made molds can be found in hobby shops or through companycasting companies. Usually, pre-made molds are used in miniature castings. Manyindividual metal casters prefer to make their own molds since it is inexpensiveand allows them greater control over the finished casting. Metal casting involves several sets of skills and mold making is one of theseskills. Mold making is an invaluable skill for metal casters as it is so veryimportant to the casting process. Not only are molds used in metal casting butin other casting types as well. Resin casting and other plastic castingrequires a mold as well. The flask can be made of wood, metal, and in somecases those toy building blocks, we all know the type. As long as the flask canhold the mold material until it dries it can be used.Every metal caster should learn how to make a mold instead of relying onothers. It's not only about independence but about saving money as well. Makingyour own mold is just cheaper.