Sand castings range from simple, unique, items to high volume products, small to massive in size, and can be engineered to develop desirable engineering properties through the appropriate selection of the materials selected.
At the low volume end of the spectrum, aluminium sculptures are sometimes produced by sand casting – often in circumstances where the use of other casting processes is inappropriate because of size limitations. A famous example of this kind of work is the famous sculpture of Aries in London’s Piccadilly Circus. Today’s production of low volume aluminum casting architectural product tends to focus on small batch production – such as decorative copings for specific installations. READ MORE »
The investment casting (or lost wax) process can be traced back to the Neolithic period around 5000BC, when, in China, brass was cast to make personal ornaments. The process can be traced through to 3200BC in Mesopotamia and Israel later spreading around the Mediterranean, through Asia to South America and Africa.
The process becomes well documented from around 1100AD when Theophilus Presbyter wrote a treatise about the process – some of which was content garnered from other sources. This documentation of the process led to its wider adoption, particularly for non-ferrous metals, and it is believed that his work led to the adoption of the process by Benvenuto Cellini (1500–1571), whose investment cast, bronze statue of Perseus with the Head of Medusa, stands in the Loggia dei Lanzi in Florence, Italy, to this day.
The process continues as a mainstream production route for individual pieces of art and jewellery because the relatively simple pattern making process is both cheap, suitable for the production of individual pieces, and very flexible – allowing artisans the creative flexibility to alter their piece of work right up to the last moment .
Wider, mass market application of the process starts in the early 20th century, roughly coinciding with the publication of a paper by Dr. William H. Taggart of Chicago in 1907. He detailed the use of a lost wax process for the production of dental plates and teeth.
The next major development occurs in the 1940’s driven by the 2nd World War, and in particular aircraft and munitions production. The need for rapid rates of production, complex (often largely hollow) shapes, and material scarcity, drove development of the lost wax process, the materials used for pattern making etc., and the diversification of the materials cast. READ MORE »
Though a relatively new process, diecasting is undergoing continual development. Currently, the development work concerns the pressure at which the molten metal is injected into the die.
This work exploits two extremes of the metal forming spectrum – the first being in the molten state, and the second being in a mildly softened state, with the material being pre- heated neither by nor sufficiently as to cause melting. READ MORE »
Permanent mold gravity die casting is an age old process that has been revived, improved and broadened in its application more recently.
As the name suggests, the process has two main features…the use of a mold which is re-used – a so called “permanent mold”, and uses gravity to transfer the molten aluminium from the crucible or furnace to the mold cavity.
There is little historic record of the development of the process, but it would be reasonable to assume that it was developed from the early application of processes such as investment casting, but where the users sought to re-use the molds. As such, it could be said that the roots of the process extend back as far as 3200 B.C., or to the early development of sand casting processes at around the same time. READ MORE »