Zirconia ceramics boast numerous advantages and are widely used in both industrial and everyday applications. However, they are relatively challenging to process due to their high level of difficulty. Initially, zirconia ceramic materials could only be processed through grinding due to their unique physical and mechanical properties. With the advancement of machining technologies, a variety of techniques similar to metal processing can now be used to process ceramic materials.

Here’s an in-depth look at the practical processing methods for zirconia ceramics:

1. Cutting Processing

Cutting is the most commonly used method in metalworking, and ceramics also have similar processing techniques.

• Cutting zirconia ceramics is applicable to both semi-sintered and fully-sintered ceramics.

• For semi-sintered ceramics, cutting aims to minimize the machining allowance for fully-sintered ceramics, thereby improving processing efficiency and reducing costs.

2. Grinding and Polishing

This method is mainly used for surface processing of zirconia ceramics.

• Grinding and polishing are ultra-precise processing methods that use free abrasives to remove material from the surface finely.

• In the ultra-precision and finishing of ceramic materials, especially in the precision machining of ceramic balls used for ceramic bearings, grinding and polishing are indispensable.

• Junjie Ceramics can achieve mirror-like finishes on zirconia ceramics, and many such products have already been delivered to clients.

3. ELID Grinding

ELID (Electrolytic In-Process Dressing) grinding is a novel grinding process.

• The principle involves using electrolysis to dress the metal-bonded grinding wheel during grinding. Electrolytic grinding fluid is poured between the grinding wheel and the tool electrode, and a pulsed direct current is applied. This process gradually removes the metal binder through anodic dissolution, exposing abrasive particles on the wheel surface to maintain its sharpness during grinding.

• While this advanced process is not yet widely applied, it demonstrates significant advantages in processing zirconia ceramics.

4. Plasticity-Based Processing

• Traditional material removal methods generally involve brittle or plastic removal mechanisms.

• Brittle removal occurs through crack propagation and intersection, while plastic removal involves shearing chips to create material flow. For metals, plastic cutting mechanisms are easily achieved. However, brittle materials like engineering ceramics and optical glass often result in brittle removal under traditional processing methods, leading to poor surface quality.

• In ceramic processing, a very shallow cutting depth can enable plastic removal, transitioning the removal mechanism from brittle fracture to plastic deformation.

5. Ultrasonic Processing

• Ultrasonic processing involves applying ultrasonic vibrations to the tool or the workpiece, with liquid or paste abrasives introduced between the tool and workpiece.

• With light pressure, the tool presses against the workpiece to achieve material removal.

1. High Cost, Low Efficiency, and Limited Precision

Although there are various methods for processing zirconia ceramics, the high hardness of the material makes processing costly, inefficient, and less precise.

• Semi-sintered or calcined zirconia ceramics are typically rough-processed using cutting methods, while grinding is used for fine processing after sintering.

2. Large Processing Allowance

• Depending on the specific zirconia ceramic application, machining may be bypassed altogether, with grinding directly applied to sintered bodies to achieve design precision.

• While the processing steps for zirconia ceramics are similar to those for metal parts, the processing allowance is significantly larger for ceramics.

• Semi-sintered or calcined ceramics often face issues like insufficient strength, surface defects, or poor clamping, which prevent achieving the desired final shape.

• Due to the uneven shrinkage during sintering, rough processing dimensions must not approach final dimensions, leaving a substantial allowance for fine processing.

• For metals, the fine processing allowance is typically within fractions of a millimeter, accounting for heat treatment or surface scaling. In contrast, zirconia ceramics require allowances of several millimeters or even over ten millimeters, significantly reducing productivity and increasing production costs.

3. High Tooling Costs

• The cost of cutting tools is a significant issue in zirconia ceramics processing. Expensive sintered diamond or CBN (cubic boron nitride) tools are required for cutting, and diamond grinding wheels dominate fine processing.

• Tooling costs for zirconia ceramics are tens to hundreds of times higher than those for metal cutting tools.

• The strength of zirconia ceramics is highly sensitive to processing conditions, making high-efficiency processing difficult to achieve. As a result, the overall processing cost for zirconia ceramics is substantially higher than for conventional materials.