Metal Casting Processes
What is Metal Casting?
Metal casting is an old-fashioned process. In the process of metal casting, metal forms come from a mold that cools liquid metal and later extracts it from the mold. The first and most significant industrial process in history was, of course, metal casting. It is used to create many metal objects used in our everyday lives: car parts, train wheels, lamp posts, pedals for school busses, and many more. In addition, metal casting foundries use metal recycling as an economic raw material source, reducing surplus scrap metal that could end up in deposition significantly.
The History of Metal Casting
The oldest metal casting known is a copper frog, which is thought to have been manufactured in Mesopotamia in 3200 BCE. Iron was discovered later, around 2000 BCE. The first cast iron manufacture was developed in China, however, only around 700 BCE. In 645 BCE, China invented the sand molding method for casting metals.
Since the start of the 1st century, the crush process, a method used in the manufacture of fine or tool metal, has been found and lost in various parts of the world. The technique first emerged in India and central Asia, until around 800 CE, which made Viking swords, appeared in northern Europe. The method was not reappearing until 1750 when it was reinvented in England by Benjamin Huntsman. In a closed crucible that is a refractory ceramic pot that can withstand a high degree of heat, Huntsman heated small parts of carbon steel. To order for Huntsman to melt steel first, the temperature was high enough.
The casting of metals into functional items has changed over the last thousand years to become more precise and efficient, but the method at its heart has remained essentially the same. Foundry process automation innovations, such as the VIBRA-DRUM ® SandCasting Conditioner by General Kinematics, have simplified the processing of large casting quantities as well as improved casting quality.
The Metal Casting Process
- Patternmaking – A model is a replica of the outside of the cast. Models usually consist of wood, metal, plastic, or plaster. For industrial component making, where accurate calculations are required for components to fit and work together, the design is incredibly important.
- Coremaking – If a casting is holes, the internal shapes of the casting are formed by an additional piece of metal or sand (called a core). Cores are usually solid but collapseable, enabling the casting to be extracted easily.
- Molding – Just imagine walking on the beach to the sea to visualize the casting process. See a footprint in the wet sand, which you leave behind. Your feet would be central, and your foot's mold is the impression left in the sand. Molding is a multi-step process which uses molding sand to form a mould around the pattern. A mold is included in a container called a bottle while casting. Green sand, or sand that is molded, is packed into the template flask. Instead, a non-destructible two-piece metal type is made so that the same pieces can be casted for industrial applications repeatedly.
- Melting and Pouring – It is poured into the mold and left to solidify if liquid metal becomes molten. The shakeout process, when solidified, starts: the moulds vibrate and sand is removed. Due to its powerful and smooth operation, equipments like our two-mass shakeouts maintain high production output in industrial applications. Usually, extracted sand is gathered, refrigerated and stored for further use in future casts. This sand separation process from coulages by the removal and cooling of sand and castings is improved by the VIBRA-DRUM ® sand casting conditioner while at the same time alleviating the common casting damages in this process.
- Cleaning – The cast metal object is removed in this final step from the mold and then fatted. During the fettling process, the artifact is washed and rough borders are stripped from any moulding product.
The Sand Casting Conditioner VIBRA-DRUM ® excellently cools, equalizes and reclamates sand from casts. In its high quantities of mold and sand for foundry applications, the machine is groundbreaking. The sand for castings is tumbled down while the sand temperature is cooled and the moisture evaporated. The final result is a clean cast and sand ready for recovery.
Modern Day Castings
Today almost all mechanical equipment that we use, from vehicles to washing machines, are constructed from metal components that were produced during the casting process. The difference between today's cast metal goods and those produced 100 years ago is the exactness, tolerances and modern methods used to produce precise core and moulding by a computerized digital design.
Different combinations of raw materials were produced throughout the centuries to produce different types of metals. Many cast materials are used in motors with a high temperature and cold sensitivity. The iron cast pipe must resist high pressure and corrosion. Slight, but durable, cast parts should be other parts. Parts are designed to provide accurate tolerance between expansion and contraction in many applications. The progress in the quality of cast metal products begins with the mineral quality itself.
