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There are many alternatives of casting. But when the resources are limited then casting is best suited for producing metal objects. The alternatives of sand casting process are:
- Metal joining (Which involves Different types of Welding methods such as Tungsten Inert Gas or TIG , Metal Inert Gas or MIG welding)
- Pressing etc.
Advantages of Sand Casting Process
- If the above mentioned alternative methods don't produce any particular advantage then the solution to the problem of production method may be lies in casting. The main advantage of sand casting process is it produces identical products cheaply.
- It produces precision objects which is not possible in any other process.
Types of Sand Casting process
- The size of the original object to be cast (the pattern) . There are different types of patterns that are used on the sand casting process.
- Quality of surface finish .
- Detail, intricacy of the design.
- Number of castings needed to be produced.
What is Sand Casting ?
Sand casting is a metal casting process which involves the use of natural sand along with adequate proportion of clay (as a binder material) to keep the sand grains together or it can use the silica sand and artificial binder pair. The mixture is then contained in a moulding flask or moulding box consisted of two matching parts . The mixture in the box is compressed by hand or mechanical ramming is done around the pattern. A parting sand is used between the two halves of the moulding flask. When the these boxes are separated after establishing the sprue system by patterns and the dowels a negative mould shape is left behind in the moulding sand. The molten metal is then poured into that hollow section or cavity. These are the basic steps of sand casting used for metal casting.
Different sand casting processes and their pros and consSand casting process involves the use of different types of sands and binder pairs. There are different types of molding sand in a casting process. And the quality of the casting depends on the properties of various natural and synthetic molding sands. Below the main types of sand casting processes are discussed with there advantages and limitations along with comparisons.
Green Sand Moulding
- Adequate amount of water is added to the sand.
- After adding water the green or natural sand is thoroughly conditioned and mixed with the help of rollers. The clay and water works as binder which holds the sand grains together.
- The sand is compressed around the pattern and rammed so that it becomes compact and tight. And this is known as 'Green Strength'.
Dry sand casting process
- This mixture is rich in clay.
- The rammed sand is more compact.
- It needs well ventilation with the appropriate use of venting rod.
- Sand must dried before pouring the molten metal into the mould.
Carbon dioxide-silica sand moulding
- Sand grains are bound together with the use of Sodium Silicate and it is hardened by the use of Carbon dioxide gas.
Synthetically bonded sand casting process
- This process uses silica sand.
- Synthetic resin is used as a binder. These binders can be air set, or thermo set or can use catalysts.
Floor Moulding process
- This process is used mainly for large castings alone.
Loam Moulding Process
- Comparison of different casting processes.
- Advantages and disadvantages of centrifugal castings.
- Different types of welding defects.