History of Gravity Casting
Compare to Aluminum die casting, Gravity Casting is very similiar to Aluminium die casting, magnesium die casting and zinc die casting,
Research and development in gravity casting has taken an important step in making metal products a part of our day to day lives. The products used in homes, aircrafts, artifacts, automobiles have become more durable and less expensive. Cast alloy parts are formed by melting the alloy and then pouring it in a mold under heavy pressure or vacuum. Gravity casting is also known as vacuum casting. It is a technique in which large diameter filaments are used with adequate separation. This ensures that no clusters are formed and also good metal wetting of the fiber is guaranteed. This technique was first used in 1970. The gravity casting method has advantages like cost effective, good quality, and process control over other casting techniques.
Gravity casting is done in ceramic molds, sand, permanent casting and also in investment or lost wax casting. The gravity casting process was started with common steel after successful implementation it was further tried on heat resistance super alloys. With recent development and with more refined methods today even titanium alloys are being cast using the gravity casting method and using ceramic crucibles. The use of desired mold designs and also specially made unique designs enable a reduction in the metal cast to yield the given part. This also helps in reducing the amount of energy that is used in making such casting articles.
With new developments, today even computerized control of the vacuum pressure and rate is possible. This enables the user to control the filling rate. This makes casting of high quality metals like and viscous metals like metal matrix and composites of aluminum casting possible. This gravity casting method is used to produce casting worth of more than $200 million. The industry is expected to grow rapidly in the coming years due to the increase in production of automotive exhaust manifolds in stainless steel.
The first ever commercial use of this computerized technology, was made by Howmet Industries of Whitehall, Michigan. They used this technology to precisely cast and design turbine blades used in aircrafts. This technology is also being used by Ford Motors to develop and improve the casting process of light truck and automobile engine blocks.
Today, metal parts fabricated using gravity casting method is being used in 90 per – cent of all durable goods. Goods like stoves, washing machine, automobiles, refrigerators, lawn mowers, cars and even boats. Many other articles like badminton rackets, tennis rackets, and even football studs are made by using light weight metals which are gravity casting method. This gravity casting method has been used to develop metal alloy parts, which are used for the auto and airline industries, which is said to make vehicles lighter though much stronger and extremely efficient.
Alloys like ferric cast metals, casting grade iron and steel are typical metals that are used for gravity casting. Also die cast grade zinc can be cast using gravity casting method. Also other raw materials like sand, spin or plaster are used. Aluminum is also used, but it is very difficult to gravity die casting a lot of care needs to be taken and proper pressure should be applied to obtain the desired shape and effect.