Ceramic Injection Molding (CIM)

Ceramic Injection Molding (CIM)

Ceramic Injection Molding (CIM) excels at various engineering applications and meeting material properties requirement such as chemical inertness, high temperature stability, wear resistance and electrical insulation.

Ceramic injection molding (CIM) has been practiced for more than 30 years, but has been restricted to niche applications with simple geometries such as the ceramic cores for investment casting. The manufacturing process of CIM is fundamentally similar to that of Metal Injection Molding (MIM), but contains subtle and important differences in its processing parameters.

Jiangsu Tech is well positioned to overcome traditional manufacturing problems via the CIM process with developments in binder technology, feedstock productions, automated molding equipment, tooling design, sintering, and quality control systems. This process will enable the cost-effective production of parts with a range of geometric complexities.

The Ceramic Injection Molding Process

The CIM process begins with very fine ceramic powders. The powders are compounded with polymer binders to produce a pelletized feedstock. During molding, binders melt to form a liquid medium that carries the ceramic powders into the mold during the injection stage.

Using an injection molding machine similar to that used in conventional plastic molding, the feedstock is forced into a mold cavity forming a net shape part. Molds can be single-cavity or multi-cavity configurations.

After forming, the part goes through a two-stage process. First is pyrolysis or “debinding” to remove the binder, followed by sintering in a high temperature kiln to form a fully dense ceramic component. Sintering is the process of heating the material to a temperature below the melting point but high enough to allow fusion of individual particles and densification of the material.

During sintering, the component shrinks by as much as 20% while retaining the original geometric shape. With good process control, it is possible to achieve a uniform and repeatable shrinkage leading to tight tolerances, obviating any need for machining of the part afterwards.

Benefits of Ceramic Injection Molding

The well-known benefits of ceramic material include: high hardness and mechanical strength; wear and corrosion resistance; dimensional stability over a wide range of temperatures; ability to withstand high working temperatures; good electrical insulation and excellent dielectric properties. However, until recent advances in CIM technology, production engineers and product designers did not view ceramics as a viable option for complex parts requiring tight dimensional tolerances.

Combine ceramic materials and injection molding, and you get these benefits:
• Small, highly complex geometries you can’t get with other forming processes, such as pressed powder and machining
• High strength
• Superior corrosion resistance
• Complex geometries without machining
• Excellent surface finish
• Overall part size and weight reduction
• Consolidation of multiple components into a single design
• Reduction of part count and assembly time

Ceramic has been a material of choice for demanding parts that require high resistance to heat, corrosion, and wear. Today, Jiangsu Tech ceramic injection molding (CIM) services make it possible to manufacture this durable material into small and micro-sized parts with complex geometries.