One places castings in the category of original mouldings and not, e.g., of forgings, which fall under (re-)shaping. This means that a component is created for the first time. The fact that casting is well suited for mass-production is shown impressively in the video below. In principle, one can process:
|Iron 1538°C |
| Heavy metals ||Tin 231°C|
Chrome 1907 °C
| Light metals ||Magnesium 650°C|
In the video-clip below, one could suspect, due to the close proximity of the fork-lift to the molten material, that a light metal with a distinctly lower melting point is being processed.
Very large vehicle components can be produced using this technology, e.g., cylinder heads- and blocks for marine engines, sometimes several stories high. Indeed, the whole manufacturing process can take up to three months. In the video below it takes a lot less time. These are not one-off forms which have to be remade over and over again, they are long term reusable moulds.Casting is by no means a simple process. It has to be preceded by an enormous amount of preparation. Previously, not only was there a drawing made but also a complete model was produced in a woodworking shop. Thereby, the amount of shrinkage which takes place when the cast cools down, also has to be taken into consideration.
In particular, the casting of bells carried the risk of having blowholes and cracks. It must be possible to have a smooth, even filling of the mould, without any air-pockets developing, which could affect the final appearance. The best thing to do is to X-Ray the finished product, like in the production of aluminium wheel-rims. Should the componenent fail the test, it can be melted down again. 09/11