Precision Machining of Ceramic Parts

Ceramic sintered parts refer to mechanical parts made of special ceramic materials through mixing, molding, sintering, and processing. These ceramic materials can be oxide ceramics, nitride ceramics, boride ceramics, carbide ceramics, etc.

Ceramic sintered parts have many properties that metal materials do not have, such as high strength, high hardness, high elastic modulus, high temperature resistance, wear resistance, corrosion resistance, oxidation resistance, thermal shock resistance, etc.
Ceramic parts are widely used in the semiconductor industry. They are favored because ceramic materials have a series of excellent properties, such as high hardness, high temperature resistance, good insulation and chemical stability, and in some cases, high thermal conductivity. The finishing of ceramic parts is a very critical step in the entire manufacturing process. It is directly related to the final dimensional accuracy, surface roughness and overall performance of the parts.

Steps for finishing ceramic sintered parts:
1. Grinding:
Dry grinding: Suitable for removing more excess in the initial stage, using hard abrasives such as diamond abrasives.
Wet grinding: It is carried out in the grinding liquid, which helps to reduce the grinding temperature and crack risk, and is suitable for more delicate surface treatment.

Plane grinding, internal grinding, external grinding: Choose the corresponding grinding method for ceramic parts of different shapes.

Polishing: Mechanical polishing: Use soft polishing discs and polishing pastes to remove surface microscopic defects through tiny abrasive particles to achieve a mirror effect.  Chemical mechanical polishing (CMP): It uses a combination of chemical corrosion and mechanical grinding, which is suitable for parts with complex shapes and high precision requirements.

Magnetorheological polishing (MRF): It uses a magnetic field to control the viscosity and shear force of the polishing liquid to achieve nano-level surface finish.

Laser processing: It is suitable for high-precision and complex-shaped ceramic parts, such as drilling and cutting, which can minimize the heat-affected zone and maintain material properties.

Grinding and polishing are post-processing reasons for ceramic parts manufacturing:

1. Improve surface finish: Due to the hard and brittle characteristics of ceramic materials, the surface may have obvious processing marks and minor defects after conventional processing. Grinding and polishing can remove these marks and significantly improve the smoothness and finish of the surface, which is essential for parts that require high-precision fit, sealing or optical performance.
2. Achieving precision dimensions: Although ceramic parts have certain dimensions after molding and sintering, it is often necessary to remove excess material by grinding to ensure the accuracy of the final dimensions and meet the needs of precision assembly.
3. Improving surface integrity: Grinding and polishing can reduce or eliminate surface defects such as microcracks and surface layer damage, which is very important for enhancing the mechanical strength, wear resistance and service life of ceramic parts. Good surface integrity is essential, especially in applications that are subject to high stress or corrosive environments.
4. Improving functional performance: In the fields of electronics, semiconductors and optics, the surface quality of ceramic parts directly affects their electrical properties, thermal conductivity and optical properties. For example, polishing of ceramic substrates can reduce the loss of signal transmission and improve the reliability of integrated circuits.
5. Aesthetic needs: In some consumer products or decorative items, the appearance of ceramic parts is equally important. Grinding and polishing can give the ceramic surface a mirror-like gloss, enhancing the visual appeal and texture of the product.
6. Meet special processing requirements: For ceramic parts with complex structures such as precision grooves and holes, grinding and polishing are effective means to achieve precise processing of these details, ensuring that the dimensions of each part are accurate, the edges are neat and burr-free.

Advanced functional ceramic materials play a vital role in the industrial field with their excellent performance. However, the widespread application of ceramic materials is still facing many problems and challenges, among which reliability, density and strength are the main constraints. How to achieve rapid densification of materials at a lower sintering temperature and prepare ceramic blocks with no pores, uniform structure, fine grains and grain boundary strengthening is still the goal that ceramic material scientists are constantly pursuing.