Keramika z cyrkonii offer superior wear resistance compared to alumina ceramics. This is attributed to the higher sintering temperatures required for zirconia ceramics, as well as a density that is twice that of alumina ceramics.

Keramika z cyrkonii possess excellent properties, including high melting and boiling points, high hardness, electrical insulation at room temperature, and electrical conductivity at high temperatures.

Pure zirconium dioxide appears white, yellow, or gray depending on impurities; it typically contains hafnium dioxide, which is difficult to separate. Proven global zirconium reserves amount to approximately 19 million tons. Zirconia is generally produced by refining zirconium ore. Under atmospheric pressure, pure zirconia exists in three crystalline forms: monoclinic, tetragonal, and cubic. These forms exist within distinct temperature ranges and can transform into one another:

Relationship between temperature and density:

(1) Monoclinic zirconia: Temperature < 950°C, density 5.65 g/cm³.

(2) Tetragonal zirconia: Temperature 1200–2370°C, density 6.10 g/cm³.

(3) Cubic zirconia: Temperature > 2370°C, density 6.27 g/cm³.

Due to advantages such as high toughness, high flexural strength, superior wear resistance, excellent thermal insulation, and a coefficient of thermal expansion similar to that of steel, zirconia ceramics are widely used in the field of structural ceramics. Key products include Y-TZP grinding balls, dispersion grinding media, nozzles, ball valve seats, zirconia molds, micro-fan shafts, fiber optic ferrules and sleeves, wire-drawing dies, cutting tools, wear-resistant cutters, clothing buttons, watch cases and straps, bracelets and pendants, ball bearings, and golf putters, among other wear-resistant components.

Ceramika aluminiowa are ceramic materials primarily composed of aluminum oxide (Al2O3) and are used in thick-film integrated circuits. They possess excellent electrical conductivity, mechanical strength, and high-temperature resistance. It should be noted that ultrasonic cleaning is required. Alumina ceramics are highly versatile; due to their superior properties, they are increasingly used in modern society to meet both everyday needs and specialized performance requirements.

Alumina ceramics are categorized into two types: high-purity and ordinary.

High-purity alumina ceramics are materials with an aluminum oxide content exceeding 99.9%. Because they require sintering temperatures as high as 1650–1990°C and possess a transmission wavelength of 1–6 μm, they are often used to make vessels for melting glass—serving as a substitute for platinum crucibles. Their light-transmitting properties and resistance to alkali metal corrosion make them suitable for use in sodium lamp tubes, while they also serve as integrated circuit substrates and high-frequency insulating materials in the electronics industry.

Ordinary alumina ceramics are classified based on their aluminum oxide content into grades such as 99, 95, 90, and 85 (indicating the percentage of Al2O3), among others. Materials with an Al2O3 content of 80% or 75% are sometimes also classified as ordinary alumina ceramics. Among these, 99-grade alumina ceramics are used to manufacture high-temperature crucibles, refractory furnace tubes, and specialized wear-resistant components such as ceramic bearings, seals, and water valve parts. The 95-grade ceramic is primarily used for corrosion- and wear-resistant components. The 85-grade ceramic is often mixed with talc, which enhances its electrical properties and mechanical strength; it can be sealed with metals such as molybdenum, niobium, and tantalum, and is used in electric vacuum devices. It exhibits the following characteristics:

(1) High Hardness

Measurements by the Shanghai Institute of Ceramics, Chinese Academy of Sciences, show a Rockwell hardness of 80–90. This is second only to diamond and far exceeds the wear resistance of wear-resistant steel and stainless steel.

(2) Excellent Wear Resistance

Tests conducted by the Powder Metallurgy Research Institute of Central South University indicate that its wear resistance is 266 times that of manganese steel and 171.5 times that of high-chromium cast iron. Under identical operating conditions, the service life of the equipment can be extended by at least tenfold.

(3) Lightweight

With a density of 3.5 g/cm³—only half that of steel—it significantly reduces the load on the equipment.

3. Comparison: Zirconia Ceramics vs. Alumina Ceramics

Zirconia ceramics offer superior wear resistance compared to alumina ceramics. This is attributed to the higher sintering temperature of zirconia ceramics; their density is twice that of alumina ceramics.