Service
china sand casting factory
eric@sanonchina.com
Definition
Sand casting refers to a casting method in which castings are produced in a sand mold. Steel, iron and most non-ferrous alloy castings can be obtained by the sand casting process. Undoubtedly, the material used in aluminum sand casting is molten aluminum.
Aluminum sand casting molds are cheap and easy to obtain, and can be produced in single pieces, in batches or in mass production.
Therefore, aluminum sand casting has been a common process in aluminum casting production for a long time.
Capabilities
Type: green sand casting, resin sand casting
Shape: complex
Weight: 1kg-300tons
Tolerance: ± 0.7mm
Surface finish – Ra: 300 – 600 μin
Max wall thickness: 3-120mm
Lead time: weeks
Material: aluminum alloy
Components
Components of the aluminum sand casting process：
1. Patterns: Used to create mold cavities. Materials used for patterns include wood, plastic and metal. When single piece or small batch production, mostly use wood mold pattern. Because wood is easy to process and the mold making method is simple. When mass production, aluminum alloy, plastic and other materials are often used to make mold patterns or core boxes.
2. Moulding Sand: Refers to the material used to make sand molds or sand cores. The basic materials for making moulding sand are foundry sand, binder, water, additives (such as coal powder, wood chips, etc.)
According to the different binders used in the sand, can be divided into green sand, water glass sand, cement sand, resin sand, etc. Among them, green sand, water glass sand and resin sand are the most used.
Characteristics of moulding sand: Permeability ,Strength ,Thermal stability,Fineness,Collapsibility
Types of foundry sand : Silica sand, Zircon sand, Olivine sand, Magnesium sand, Bronze sand.
Types of binder: Clay, Water glass, Vegetable oil, Synthetic resin.
3. Sand Core: Mainly used to form the inner holes and cavities of castings. The sand core is mostly surrounded by high temperature liquid metal in the mold, while the size of the supporting part is generally small. Therefore, the core sand should have the properties of general moulding sand, but also requires high strength, permeability, yielding and collapse.
Commonly used sand cores include clay sand core, oil sand core, resin sand core and water glass sand core.
4. Pouring System. The pouring system design is an important part of producing high quality castings. Its role is to control the metal liquid filling speed and filling time, so that the metal liquid can enter the mold smoothly, and at the same time, it can prevent slag and other inclusions from entering the cavity and reduce the secondary oxidation of the metal liquid as much as possible.
Types of Sand Casting
There are three types of sand casting processes: dry sand casting, green sand casting, and resin sand casting. When we choose the aluminum sand casting process, the most commonly used are green sand casting and resin sand casting.
Green Sand Casting
Green sand casting is the most widely used method in the sand casting process, and green sand accounts for about 60-70% of all sand usage.
The basic feature of green sand casting is that the sand mold (core) does not need to be dried and there is no hardening process. Its main advantages are: low material cost, short production cycle, easy to realize mechanization and automation of production, and save drying equipment.
However, green sand casting also has some defects, such as poor dimensional accuracy of castings, sticky sand, pores, etc.
Resin Sand Casting
Resin sand casting is also one of the sand casting methods we are proficient in. Compared with other sand casting methods, the quality of castings produced with resin sand is greatly improved:
- The casting has high dimensional accuracy, smooth surface and clear outline.
- The production efficiency is high and the production cycle is shortened.
- The yield is high, which greatly reduces the defects of castings such as pores, shrinkage porosity, and cracks.
Aluminum Sand Casting
As a professional aluminum casting factory, aluminum sand casting is also one of the casting processes that we are skilled in. If you have a project for aluminum sand casting, you can also let us know.
Sand Casting Steps
- Mold Assembly – Preparing the mold is the most important step of the sand casting process. Without it, no metal can be cast. It is made by mixing four essential components: molding sand, additives, binders, and parting compounds. The sand can be packed either by hand or by machines for producing bulk quantities.
- Pouring – Once the mold is ready, the next step is to pour in the molten metal inside. As the liquid metal flows inside, it will fill the mold cavity and form the desired shape.
- Cooling – The third step of the process is when the metal begins to solidify and cool. During this time, it is very important not to open the flask until it is completely solid, so as to avoid surface defects. The cooling time of the cast is calculated depending on how thick and how hot the metal is.
- Removing – Once the metal has cooled, the mold is carefully removed from the flask. This process can be done by breaking open the mold, or by shaking it out.
- Trimming and heat treatment. The castings are deburred and polished after removal. Heat treatment（T5&T6）is also performed in order to eliminate internal stresses and improve mechanical properties of the casting.
Sand Casting Products
We have 5 sand casting lines, two techniques: green sand casting and resin sand casting.
If you need to cast products with complex shapes and inner cavities, we can do it.
If the weight of castings ranges from a few grams to hundreds of tons, we can do it.
If the size is relatively close, reducing the machining allowance, we can do it.
If you want the sand-castings with good surface, precise dimension, excellent porosity and shrinkage control, we can do it.
Contact Us Now
If you have a sand casting project, please let us know and we will definitely be a good partner for you.
