Figure 1: CRAC zirconia ceramic parts classification system, showing the four material series (Y8/A-ZR, 3Y/Y-ZR, PR-ZR Yellow Zirconia, and Composite Ceramics) with their representative products including spools, plungers, grading wheels, ball mill jars, and wire drawing components.

Classification of Zirconia Ceramic Parts

Structural ceramics belong to a category of ceramic materials whose primary function is to exhibit mechanical, thermal, and chemical properties. The material's ability to be reliably utilized under a variety of extreme operating conditions renders it a crucial enabling factor in numerous emerging scientific and technological fields. CRAC's zirconia ceramic parts are classified into four categories, each with distinct material characteristics and application advantages:

1. A-ZR (Y8 Series) - Composite Stabilized Zirconia

The Y8 series is a composite stabilized zirconia part independently developed by CRAC, featuring outstanding performance and being particularly suitable for dry grinding technology related ceramic accessories applications. Representative products include spools, plungers, grading wheels, mixing rods, molds, shafts, and liners. The composite stabilization mechanism provides enhanced thermal shock resistance and fracture toughness compared to singly stabilized variants, making Y8 series parts ideal for applications involving rapid temperature cycling and mechanical impact loading.

2. Y-ZR (3Y Series) - Yttrium Stabilized Zirconia

The 3Y series is yttrium stabilized zirconia (Y-TZP), the most widely used zirconia ceramic material in structural applications. Representative products include ball grinding jars, turbines, nozzles, molds, tools, and shafts. The 3Y designation refers to the 3 mol% yttria content that stabilizes the tetragonal phase of zirconia at room temperature, enabling the transformation toughening mechanism that gives Y-TZP its renowned fracture toughness (typically 8-10 MPa.m^1/2). This material system provides the optimal balance of strength, toughness, and cost for general structural ceramic applications.

3. PR-ZR (Yellow Zirconia Series)

The yellow zirconia series is yellow yttrium stabilized zirconia, distinguished by its characteristic color while maintaining performance identical to white yttrium stabilized zirconia parts. Representative products include spools, tower wheels, and drawing wheels. It is important to note that CRAC's yellow yttria-stabilized zirconia parts are not common magnesium-zirconium products found on the market; their performance is exactly the same as that of white yttrium-stabilized zirconia parts. The yellow coloration is a result of specific raw material processing and does not affect the mechanical, thermal, or chemical properties of the finished component.

4. Composite Ceramic Parts Series

Composite ceramics represent a novel type of ceramic material independently developed by CRAC. The fundamental principle is to employ a specific process to infiltrate polymer material into the ceramic grain boundary, thereby significantly enhancing the toughness of the ceramic material. This technological advancement has greatly expanded the application field of ceramic materials. Currently, CRAC provides a variety of composite ceramic parts including composite zirconia ceramic parts, composite silicon carbide ceramic parts, and composite alumina ceramic parts. The polymer-infiltrated grain boundary structure arrests crack propagation and redistributes stress, achieving fracture toughness values that exceed those of monolithic ceramics while maintaining excellent wear and corrosion resistance.

Technical Parameters of Zirconia Ceramic Parts

The following table presents the key technical parameters for the three primary zirconia ceramic material series, tested according to Chinese national standards (GB/T):

Processing Capabilities and Precision Limits

CRAC's zirconia ceramic parts manufacturing capabilities encompass both cylindrical and disc-type components with industry-leading precision. The following specifications define the processing limits for each component category:

Industrial Applications of Zirconia Ceramic Parts

CRAC's zirconia ceramic parts serve six major application categories, each exploiting the unique material properties of zirconia ceramics to solve specific industrial challenges:

1. Ceramic Valves

Ceramic valves have been widely used in industrial domains such as electric power, petroleum, chemical engineering, metallurgy, mining, and sewage treatment. Especially under extreme conditions such as high wear, strong corrosion, and high temperature and pressure, ceramic valves manifest their outstanding performance advantages compared to traditional metal valves. The component in contact with the medium is entirely fabricated from ceramic structural materials, guaranteeing reliability and durability in harsh environments. CRAC's ceramic valve series, including valve bodies, valve seats, valve sleeves, and valve cores, is renowned for its exceptional chemical stability and hardness, showcasing remarkable wear resistance, corrosion resistance, and high-temperature resistance, along with outstanding thermal insulation properties and a low coefficient of thermal expansion.

2. Ceramic Wire Drawing Parts

As an important part of wire drawing machine equipment, zirconia ceramic tower wheels have won the favor of wire drawing machine manufacturers for their excellent wear resistance, high strength, corrosion resistance, and high temperature resistance compared with traditional metal steel or cast iron. In practical applications, zirconia ceramic tower wheels not only effectively reduce the production cost of the wire drawing machine but also significantly extend the service life of the equipment and enhance the quality of the drawn wire. CRAC's yellow yttria-stabilized zirconia (PR-ZR series) is the preferred material for wire drawing applications, offering performance identical to white yttria-stabilized zirconia while providing a distinctive visual identifier for quality assurance.

3. Planetary Ball Mill Ceramic Parts

Zirconia ceramic ball mill jars, as products commonly used in laboratory ball mills, have the characteristics of high hardness, high toughness, and wear resistance, while showing excellent high temperature resistance and chemical resistance, as well as a long service life. The overall structure design of CRAC's ceramic ball mill jars is reasonable, showing the characteristics of large arc angles, and the sealing performance of the tank mouth is good, ensuring that there will be no material leakage or the formation of grinding dead angles during use. CRAC also provides ceramic and metal bonding services using epoxy resin or ceramic adhesive bonding methods for ball mill jar assemblies requiring integrated metal fittings.

4. Air Jet Mill Ceramic Parts

For the production line of airflow mills required for the production of high-purity and high-end materials, CRAC has adopted zirconia ceramic materials to make parts such as classifier wheels, hammers, nozzles, grinding discs, and toothed rings for powder equipment. Ceramic materials possess excellent wear resistance, corrosion resistance, and high-temperature resistance, while also having good biocompatibility and not introducing metal contamination, thereby ensuring that the produced materials have higher purity, finer particle size, and cleaner quality. Zirconia nozzles, as a type of high-precision ceramic component, have become an indispensable core part in many industries due to their unique advantages and wide range of applications.

5. Ceramic Pump and Plunger Components

Ceramic plungers play a key role in filling systems, where they achieve the intake and discharge of liquids through reciprocating motion within the cylinder. Compared to traditional metal alloys, ceramic materials stand out for their high strength, hardness, resistance to high temperatures, corrosion, superior wear resistance, excellent biocompatibility, and the absence of metal contamination. Moreover, ceramics have a thermal conductivity that is markedly different from metals; they are excellent insulating materials. Under fluctuating temperatures, ceramic materials exhibit a low coefficient of thermal expansion, ensuring good dimensional stability throughout the pump's service life.

6. Ceramic Parts for Bead Mills

With the increasing application of new energy and nano new materials, the demand for ultrafine grinding equipment such as horizontal bead mills, vertical bead mills, and agitator mills is constantly increasing. Zirconia ceramic accessories, including grinding discs, turbines, pulleys, rod pin sleeves, rod nails, grinding blocks, and screens, are widely used in industries such as electrode materials, nanomaterials, inks, pharmaceuticals, chemicals, and ceramics due to their excellent performance and low wear rate, effectively improving grinding efficiency and reducing equipment wear.

Production Process and Quality Control

CRAC's zirconia ceramic parts manufacturing follows a five-stage production process, each with dedicated quality control protocols:

Raw material quality control includes particle size analysis (laser particle size analyzer), moisture content measurement (halogen moisture analyzer), bulk density verification (precision balance), compression performance testing, and glue content determination. Shipment inspection covers appearance and dimensional specification inspections for conventional products, with red dye penetration or ultrasonic (UT) non-destructive testing for specific critical components.

Material Selection Guide: A-ZR vs 3Y vs PR-ZR vs Composite

Frequently Asked Questions