Chinese Professional Stainless Steel Investment Casting Foundry - Custom Alloy Steel Casting Product by Sodium Silicate Investment Casting – RMC Foundry

Investment casting (lost wax casting) is a method of precision casting process which can product complex near-net-shape details using replication of wax patterns. Investment casting or lost wax is a metal forming process that typically uses a wax pattern surrounded by a ceramic shell to make a ceramic mold. When the shell dries, the wax is melted away, leaving only the mold. Then the casting component is formed by pouring molten metal into the ceramic mold.

According to the different binders for shell building, the investment casting could be divided into silica sol binder investment casting, water glass binder investment casting and the investment casting with their mixtures as binder materials.

Water glass, also known as Sodium Silicate, is a kind of soluble alkali metal silicate, which is glassy in solid state and forms a water glass solution when dissolved in water. According to the difference of the alkali metals contained, there are two types of potassium water glass and soda water glass. The latter is easily soluble in water, contains less impurities, and has stable performance. Therefore, the water glass for investment casting is sodium water glass, namely Na20·mSiO2, A transparent or translucent colloidal aqueous solution formed after hydrolysis. The main chemical components of water glass are silicon oxide and sodium oxide. In addition, it also contains a small amount of impurities. Water glass is not a single compound, but a mixture of multiple compounds.

In the investment casting process, the water glass binder and coating have stable performance, low price, short shell-making cycle and convenient application. The water glass shell making process is suitable for the production of investment castings such as carbon steel, low-alloy steel, cast iron, copper and aluminum alloys that require less surface quality.

Custom alloy steel casting machinery spare parts by lost wax investment casting process with water glass (the aqueous solution of sodium silicate) as the binder materials for shell making. The quality of shell making influent the accuracy of the final castings and therefore is a very critical process during investment casting. The quality of the shell is directly related to the roughness and dimensional tolerance of the final casting. Therefore, it is an important task for the investment casting foundry to choose a suitable manufacturing method for the mold shell. According to different adhesives or binder materials for making the mold shell, investment casting molds can be divided into water glass adhesive shells, silica sol adhesive shells, ethyl silicate adhesive shells and ethyl silicate-silica sol composite shells. These modeling methods are the most commonly used methods in investment casting.

Mold Shell by Water Glass (aqueous solution of sodium silicate)
The investment casting produced by the water glass shell casting has high surface roughness, low dimensional accuracy, short shell-making cycle and low price. This process is widely used in casting carbon steel, low alloy steel, aluminum alloy and copper alloy.

Mold Shell by Silica Sol Shell (a dispersion of nano-scale silica particles in water or solvent)
The silica sol investment casting has low roughness, high dimensional accuracy, and long shell-making cycle. This process is widely used in high-temperature heat-resistant alloy castings, heat-resistant steel castings, stainless steel castings, carbon steel castings, low alloy castings, aluminum alloy castings and copper alloy castings.

Mold Shell by Ethyl Silicate Shell
In investment casting, castings made by using ethyl silicate as a binder to make the shell have low surface roughness, high dimensional accuracy, and a long shell-making cycle. This process is widely used in heat-resistant alloy castings, heat-resistant steel castings, stainless steel castings, carbon steel castings, low alloy castings, aluminum alloy castings and copper alloy castings.

Carbon steel, low alloy steel, and tool steel castings are used in several industrial applications and environments. With their numerous grades, steel and their alloys can be heat-treated to improve its yield and tensile strength; and, adjust hardness or ductility to the engineer’s application needs or desired mechanical properties.

Wear-resistant alloy steel investment castings are the casting parts produced by lost wax investment casting process made of wear-resistant alloy steel. At RMC Foundry, the main sand casting processes we could use for wear-resistant alloy steel are green sand casting, resin coated sand casting, no-bake sand mold casting, lost foam casting, vacuum casting and investment casting. The heat treatment, surface treatment and CNC machining are also available at our factory as per your drawings and requirements.

Among a wide variety of casting alloys, wear-resistant cast steel is a very widely used alloy steel. Wear-resistant cast steel mainly improves the wear resistance of steel castings by adding different content of alloying elements, such as manganese, chromium, carbon, etc., to the alloy. At the same time, the wear resistance of wear-resistant steel castings also depends on the heat treatment method used by the foundry and the structure of the casting.

According to different wear characteristics, the wear of steel castings can be divided into abrasive wear, adhesive wear, fatigue wear, corrosion wear and fretting wear. Wear-resistant steel castings are mainly used in industrial fields with complex working conditions and high mechanical performance requirements, such as mining, metallurgy, construction, power, petrochemical, water conservancy, agriculture and transportation industries. Wear-resistant steel castings are mostly used in abrasion conditions with a certain impact load, such as grinding equipment, excavators, crushers, tractors, etc.

Capabilities of Investment Casting Foundry:
• Max Size: 1,000 mm × 800 mm × 500 mm
• Weight Range: 0.5 kg – 100 kg
• Annual Capacity: 2,000 tons
• Bond Materials for Shell Building: Silica Sol, Water Glass and their mixtures.
• Tolerances: On Request.

Advantages of Investment Casting Components:
- Excellent and smooth surface finish
- Tight dimensional tolerances.
- Complex and intricate shapes with design flexibility
- Capability to cast thin walls therefore a lighter casting component
- Wide selection of cast metals and alloys (ferrous and non-ferrous)
- Draft is not required in the molds design.
- Reduce the need for secondary machining.
- Low material waste.

OEM Custom Investment Casting Products