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Investment Casting - Superior Quality and Precision by Donghua

Donghua (DH), a distinguished leader in investment casting, boasts over 20 years of experience and a steadfast commitment to delivering top-notch castings alongside unparalleled customer service. Investment casting, also known as lost wax casting, involves a metal-forming process that utilizes a wax pattern encased in water glass or silica sol to create a ceramic shell. The casting component takes shape when molten metal is poured into the ceramic mold.




Donghua consistently meets a diverse range of material specifications, adhering to ASTM, ISO, AISI, EN, DIN, SAE, and GB standards. Our extensive portfolio includes castings made from various materials such as carbon steel, alloy steel, stainless steel, and ductile iron. By employing cutting-edge technology and state-of-the-art equipment throughout every stage of the investment casting process, we achieve remarkable precision and consistently accurate results. Our capabilities encompass a wide array of castings, with lengths from 10mm to 1000mm and weights ranging from 0.1kg to 100kg.

To guarantee superior quality products, we conduct comprehensive on-site testing using advanced inspection equipment:

  • Spectrographic and manual quantitative analysis

  • Carbon sulfur analysis

  • Coordinate Measuring Machine (CMM)

  • Metallographic analysis

  • Hardness testing

  • Mechanical property analysis

  • Hydraulic testing

  • Leak detection

  • Impact testing

  • Salt spray testing

  • Paint thickness testing

  • Non-Destructive Testing (NDT) including X-ray, Magnetic Particle Testing (MT), and Ultrasonic Testing (UT)




1. Wax pattern production


Molten wax is injected into metal dies to form wax patterns. These patterns are then connected to a central gating system comprising sprue and runners, resulting in a casting cluster pattern.

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2. Ceramic shell making

The casting cluster is immersed in a slurry of fine refractory materials and subsequently coated with coarser particles multiple times. Once the shell dries, it forms a uniform ceramic coating. The inner wax pattern melts away, leaving a hollow ceramic shell layer.


3. Pouring

The ceramic shell containing the cavity is preheated to 1000°C. Molten metal is poured into the gating system, filling the mold. After cooling and solidifying, the castings, along with the gating system, are produced.


4. Divesting

The shell is vibrated to release the casting. Sawing machines are then used to remove the gating system.


5. Finishing

The casting is ground and shot-blasted to attain a smooth surface. Hand tooling and welding are employed to address impurities and defects. For certain parts, a hydraulic straightening machine may also be utilized for straightening.

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6. Heat treatment


Heat treatment enhances the casting's strength, hardness, toughness, ductility, and corrosion resistance.

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