Innovnano, Coimbra, Portugal, a manufacturer of structural zirconia ceramics, has reported the results of fracture toughness tests on its Innovnano 2 mol.% Ytrria-Stabilised Zirconia (2YSZ) structural ceramic powder using the single edge pre-cracked bean (SEPB) method with the Japan Fine Ceramics Center, Nagoya, Japan.
The results reported show that 2YSZ has outstanding fracture toughness, combined with high flexural strength and ageing resistance for physically demanding structural ceramic applications. With a value of 7.2 MPa.m1/2, the fracture toughness of 2YSZ was said to far exceed the current structural ceramic of choice, 3YSZ, which has a fracture toughness of just 4.2 MPa.m1/2.
Innovnano produces 2YSZ using Emulsion Detonation Synthesis (EDS), its proprietary technology for the high volume, high quality production of nanostructured powders. This technology produces powders with a nanostructure that provides improved structural properties such as hardness, fracture toughness, flexural strength and resistance to thermal shock.
The material is said to combine all the desired properties of 3YSZ, with the added benefit of improved fracture toughness inherent in lower yttria content YSZs.
Previously, the fracture toughness of Innovnano has been investigated using traditional indentation methods (IF) that demonstrated a fracture toughness value above 15 MPa.m1/2. This is significantly higher than the value for 3YSZ benchmark, which was found to be just 5 MPa.m1/2 using the same method.
To further qualify the outstanding fracture toughness of 2YSZ, additional tests have recently been conducted using a different measurement technique. The single edge precracked beam (SEPB) method (ISO 15732:2003) is recommended for fine grain ceramics to provide a more accurate representation of a material’s fracture toughness.
Results from the study conducted at the Japan Fine Ceramics Center confirmed the fracture toughness of 2YSZ (7.2 MPa.m1/2) to exceed that of 3YSZ benchmark (4.2 MPa.m1/2), further demonstrating the superior properties of Innovnano 2YSZ over other ceramic materials.
André de Albuquerque, Innovnano CEO, commented, “The fracture toughness of Innovnano 2YSZ powder is exceptional. Confirmed by two different measurement techniques to exceed that of 3YSZ, while maintaining its other desirable properties, it offers an exciting structural ceramic alternative.”