Application examples of ceramics

Example of Ceramics

Making best use of the ceramic characteristics

Our company specializes in machining round products. Our core specialization is machining inner surface of cylinders. Our machining track record includes injection molds/extrusion dies, bush used to guide drills and reamers, jigs such as positioning pins, and ring and plug gages. These products come with functions unique to ceramics such as slidability, rust inhibition, and insulation in addition to wear resistance.
Unfortunately, we cannot display the samples on the website. However, we will introduce the typical machining technology used by our company.

Zirconia ceramics Cylinderical pipe

Zirconia ceramics  Cylinderical pipe1
During finishing of the inner diameter, the difficulty in machining increases in direct proportion to the increase in the ratio (L/D ratio) of the workpiece length L to inner diameter D. In general, machining becomes difficult once L/D ratio crosses 3. The material of the sample is zirconia ceramic with an inner diameter 9 mm., total length 100 mm, L/D ratio exceeds 10 on calculation. This pipe has very good accuracy with a cylindricity of 0.3 μm.

Silicon nitride Thin wall pipe

Silicon nitride  Thin wall pipe1
The biggest challenge during machining of thin-walled pipes is removing the distortions in the workpiece. Workpiece with thin walls tends to distort during machining. Maintaining the cylindricity during machining becomes difficult. We are capable of machining with minimum distortion of inner diameter by using the unique technology of our company. The material of the sample cylinder is silicon nitride with approximate wall thickness 2.5 mm, inner diameter 30 mm, and a total length of 40 mm. Cylindricity of the inner surface is finished to 0.23 μm.

Zirconia ceramics Ring with ditch in the I.D.

Zirconia ceramics  Ring with ditch in the I.D.1
Machining is difficult if grooves such as relief are present on the inner surface of the work. Wire based electric-discharge machining can be used for materials such as cemented carbide or steel materials, but current cannot pass through ceramics and grooves cannot be machined by electric discharge machining. Our company offers machining services even for such requirements and can maintain the accuracy required for the roundness of the inner diameter.

Fitting technique for piston and cylinder

Fitting technique for piston and cylinder1

To move the piston (plunger) smoothly inside the cylinder (syringe), machining the cylinder inner surface with roundness and cylindricity of high accuracy is essential. Our company specializes in machining the inner surface of cylinders (zirconia ceramic cylindrical pipes). The cylindricity of cylinders is maintained below 1 μm enabling the piston to slide smoothly. We also offer consultations for products with special shapes such as large diameter and long cylinders.

Shrink fitting and cooling fitting technology

Shrink fitting and cooling fitting technology1 Shrink fitting and cooling fitting technology2

Ceramics are expensive materials compared to steel materials, in addition to the problem that machining is difficult. Shrink fitting technology is an effective method to make the best use of the characteristics of ceramics such as wear resistance and slidability. Shrink fitting process is as follows. Metal parts used for the outer diameter can be made to expand by heating. Ceramics are inserted into the inner diameter after heating. The outer diameter of the metal will shrink during the cooling process and adhere mechanically to the ceramic. For products where ceramics are used with forged molds, shrink-fitted products are found to be more resistant to cracking than ceramics alone. Since ceramic is used only in the necessary areas with remaining areas made of steel, this improves machineability.
If ceramic is required to be used on the outer diameter, the metal on the inner diameter is cooled and joined to the ceramic by using cooling fit. Ceramics cannot be used for products subject to load because the tensile strength is low.