Adding yttrium-stabilized nano-zirconia can improve the density and toughness of ceramics, improve the hardness and wear resistance of ceramics, make ceramics resistant to falling and cracking, prevent cracking, and reduce the sintering temperature of ceramics.
Principle of Nano-zirconia ZrO2 Toughened Ceramics:
1. “Refining theory”, it is believed that the introduction of nano-zirconia (30nm, 99.9%) can inhibit the abnormal growth of matrix grains, make the matrix structure uniformly refined, and thus improve the strength and toughness of nano-ceramic composite materials.
2. “Transcrystalline theory”, is believed that in nano-composite materials, matrix particles are densified with nano-particles as cores, and nano-particles are wrapped inside the matrix grains. In this way, the effect of the main grain boundary can be weakened, trans-crystalline fracture can be induced, and trans-crystalline fracture rather than inter crystalline fracture can be generated when the material breaks, thereby improving the strength and toughness of nano-ceramic composite materials.
3. The “pinhole” theory believes that the nanoparticles existing in the matrix grain boundary produce a pinhole effect, thereby limiting the occurrence of grain boundary slip, cavitation, and creep. The strengthening of the grain boundary leads to the improvement of the toughness of nanocomposite ceramics.
The mechanical properties and microstructure observation of nanocomposite ceramics show that nanocomposite ceramics have two significant characteristics:
1. The mechanical properties of nanocomposite ceramics are significantly improved, and the degree of improvement is sometimes several times.
2. Nanocomposite ceramics have an internal structure with multiple interfaces. First, the micron-sized matrix particles 0.5-5um form the main grain boundary. Secondly, the dispersed particles are often not in the main grain boundary, but in the interior of the matrix particles, forming an intracrystalline composite structure, and forming a secondary grain boundary between the nanoparticles and the main grain boundary particles. Intracrystalline structure and secondary grain boundary are new structural forms that appear in ceramic matrix composite materials. The existence of this structure has an important influence on the mechanical properties of the material.
In nanocomposite ceramics, micron or submicron matrix grains coexist with nano-reinforcement phase particles. Nanoparticles are distributed inside the material matrix grains, which enhances the grain boundary strength, greatly improves the mechanical properties and reliability of the material, and turns fragile ceramics into tough materials.
Toughened ceramic types: zirconia ceramics, alumina ceramics, and other ceramics.
Addition amount: When the content of nano-zirconia is 10-15%, the comprehensive mechanical properties of alumina ceramic materials are the best, with a bending strength of 766.74MPa, a fracture toughness of 6.13 MPa.m1/2, and a Vickers hardness of 19.31GPa, which exceeds that of single-phase alumina materials. This shows that the addition of nano-zirconia greatly improves the mechanical properties of the material.
Edgetech is committed to producing various high-performance ceramic parts in the precision ceramic processing customization field, including Alumina, Zirconia, Boron Nitride, Aluminum Nitride, Silicon Carbide, etc. Our products have excellent performance and reliability, providing customers with key support and helping customers achieve production efficiency improvement and product performance optimization.