Introduction to Zirconia Toughened Alumina (ZTA) Ceramics

Zirconia-toughened alumina (ZTA) ceramics are advanced ceramic materials that combine the high strength and hardness of alumina with the toughness of zirconia. The production process usually consists of three main steps: preparation of ceramic powder, pressing of raw materials, and sintering and processing.

Great Ceramic-Advanced Ceramics-Zirconia Toughened Alumina Ceramics

Properties of Zirconia Toughened Alumina (ZTA) Ceramics

Zirconia toughened alumina (ZTA) ceramics are superior to other materials and can be used in a variety of industrial environments, its key performance characteristics include:

  • High strength: ZTA ceramics have the high hardness of alumina, can withstand huge mechanical loads.
  • Fracture toughness: ZTA ceramics have the good toughness of zirconia, compared with pure alumina, tiny zirconia particles in the impact will be transformed into stress-absorbing micro-cracks, thus preventing catastrophic failures and fracture toughness increased by several times.
  • Thermal stability: ZTA ceramics are unaffected by searing temperatures and rapid thermal fluctuations, and are able to stand up to harsh environments.
  • Chemical resistance: ZTA ceramic substrates are highly resistant to corrosion and corrosive chemicals, ensuring long-lasting performance.

Mechanical Properties of Zirconia Toughened Alumina (ZTA) Ceramics

Item Unit Parameter
Color — white
Density g/cm³ 4.1~4.38
Hardness GPa 15
Compressive strength MPa 2350
Flexural strength MPa 700
Fracture toughness MPa·m1/2 3.5
Young’s modulus GPa 310
Poisson’s ratio — 0.26

Thermal Properties of Zirconia Toughened Alumina (ZTA) Ceramics

Item Unit Parameter
Maximum operating temperature ℃ (without mechanical load) 1500
Thermal conductivity @25℃ W/(m·K) 20
Coefficient of linear thermal expansion 40-400°C,×10-6/°C 8
Specific heat J/(kg·K) 720
Thermal shock resistance ℃(in water) 300

Electrical Characteristics of Zirconia Toughened Alumina (ZTA) Ceramics

Item Unit Parameter
Dielectric constant 1MHz 10.2
Dielectric strength ac-kV/mm 9.0
Dielectric loss 1MHz 20×10-4
Volume resistance Ω·cm ＞1014
Volume resistance Ω·cm ＞104

ZTA Ceramics Applications

Zirconia toughened alumina (ZTA) ceramics are widely used in the following industries due to its excellent comprehensive performance:

  • Pump and valve industry: Ideal for wear parts of pumps, valves and agitators that handle abrasive fluids and slurries.
  • Food and beverage processing: contamination-free washers for food processing equipment ensure hygiene and purity.
  • Chemical and pharmaceutical industry: withstand harsh chemicals and corrosive environments in reactors, agitators and other equipment.
  • Textile industry: Smooth, wear-resistant washers for guide rolls and tensioning devices to improve yarn and fabric quality.
  • Aerospace and Defense: Light weight and high strength properties make it suitable for demanding aerospace and defense applications.

ZTA Ceramics Preparation Process Steps

From inconspicuous powder to polished substrate, zirconia toughened alumina (ZTA) ceramics preparation process includes the following steps:

  1. The preparation of ceramic powder: the use of ball mills, ball mills, spray dryers to control the dosage, the preparation of ceramic powder.
  2. Pressing of raw materials: the raw materials are pressed into the desired shape and density.
  3. Sintering processing: ZTA ceramics are sintered by hot pressing, hot isostatic pressing, continuous hot pressing sintering and other methods.

Summary

Compared with other materials, ZTA ceramics are increasingly used in a variety of industrial production environments due to their versatility and superior performance. The popularity of ZTA ceramics in the industry is expected to increase as the demand for high quality ceramic parts continues to grow.