Zirconia toughened alumina

Ceramic materials have many superior properties, such as high temperature mechanical properties, chemical erosion resistance, electrical insulators, high hardness and wear resistance, but because of its structure, ceramic materials lack the force of plastic deformation caused by sliding under stress like metals, and are prone to defects, cracks and cracks. It is easy to cause high stress concentration, which determines the essence of brittleness of ceramic materials.

Zirconia toughened alumina ceramics (ZTA) have good white, corrosion resistance and chemical stability. Alumina has high hardness and good zirconia toughness. The two materials have formed excellent composites with high strength and toughness, which are more widely used. Zirconia toughened ceramics have good wear resistance because of their higher flexural strength and fracture toughness at room temperature. The specific proportion of the two materials can be adjusted according to the actual use requirements of users. The properties of zirconia toughened alumina ceramics are better than 99 alumina ceramics, and the price is much lower than that of zirconia ceramics. It is widely used in mechanical, electronic, petroleum, chemical, aerospace and textile industries.

Table of Performance Parameters of Alumina-Zirconia Structural Ceramics-ZTA Ceramics

performance	Company	Alumina Al2O3				Zirconia (ZrO 2)
performance	Company	AL2O3≥95	AL2O3≥99	AL2O3≥99.5	AL2O3≥99.8	ZTA	YTZ
bulk density	g/cm3	3.7	3.80～3.85	3.85	3.9	3.8～4.6	6
hardness	HRA≥	86	88	88	88	86～88	88～90
Flexural strength	Mpa≥	300	350	400	400	172～450	900
Service temperature	℃≤	1500	1500	1500	1500	1400～1500	1500
Coefficient of linear expansion	×10-6/℃	7.5	8.2	8.2	8.2
Dielectric constant	εr(20℃,1MHz)	9	9.2	9.2	9.2
Dielectric loss	tanδ×10-4,1MHz	3	2	2	2
Volumetric resistivity	Ω·cm(20℃)	1013	1014	1014	1014	1013	1014
Breakdown strength	KV/mm,DC≥	20	20	20	20
Acid resistance	mg/cm2≤	0.7	0.7	0.7	0.7
Alkali resistance	mg/cm2≤	0.2	0.1	0.1	0.1
Wear resistance	g/cm2≤	0.2	0.1	0.1	0.1
compressive strength	Mpa≥	2500	2500	2500	2800	2300～2900	2500
Flexural strength	Mpa≥	200	350	350	350
Modulus of elasticity	Gpa	300	350	350	350
Poisson ratio		0.2	0.22	0.22	0.22
Thermal conductivity	W/m·K(20℃)	20	25	25	25