Ultra-degradation-resistant Zirconia achieved through advanced powder manufacturing and additive technologies

Tokyo, Japan—Tosoh Corporation is pleased to announce the success of a joint research project between Japan’s National Institute for Materials Science, led by principal researcher and doctor of engineering Hidehiro Yoshida, and the University of Tokyo’s Institute of Engineering Innovation’s School of Engineering and that school’s Professor Yuichi Ikuhara. The project manufactured a nanocrystalline, ultra-degradation-resistant zirconia capable of withstanding extreme conditions beyond the resistance of conventional yttria-stabilized zirconia. Koji Matsui, who holds a doctorate in engineering and is a researcher from Tosoh Corporation’s Tokyo Research Center, is credited for his contributions to the research.

It has long been known that the strength of the fine ceramic yttria-stabilized zirconia degrades under extremely high air and water temperatures. The key to overcoming this problem is the joint research project’s development of advanced powder manufacturing and additive technologies. That combination has yielded an ultra-degradation-resistant zirconia whose strength remains intact under harsh conditions.

The results of the research project were published in the United Kingdom in a paper called “Nanocrystalline, Ultra-Degradation-Resistant Zirconia: Its Grain Boundary Nanostructure and Nanochemistry.” That paper appeared in the April 23 edition of the online journal Scientific Reports, published by the Nature Publishing Group: http://www.nature.com/srep/index.html.

Demand for zirconia in dental applications is exploding. And Tosoh Corporation hopes that the discovery of nanocrystalline, ultra-degradation-resistant zirconia further expands the use of this fine ceramic to applications previously excluded for their adverse affect on conventional yttria-stabilized zirconia.

The degradation acceleration test conducted during the joint research project used 140°C water on three high-density sintered products: a 3Y powder (3 mole percentage yttria-stabilized zirconia) and two prototypes, a 3Y-A powder (with an aluminum-sourced additive) and a 3Y-AG powder (with aluminum- and germanium- sourced additives). The 3Y sintered product displayed signs of degradation after one day, whereas the 3Y-A and the 3Y-AG sintered bodies displayed virtually no change and remarkable resistance to degradation after four years (see graph).


Tosoh Corporation is a Japanese chemical company established in 1935 and listed on the First Section of the Tokyo Stock Exchange. It is the parent of the Tosoh Group, which comprises 132 companies worldwide and a multiethnic workforce of over 11,000 people and generated net sales of ¥668.5 billion (US$7.1 billion at the year-end rate of ¥94.05 to the US dollar) in fiscal 2013, ended March 31, 2013.

Tosoh is one of the largest chlor-alkali manufacturers in Asia. The company supplies the plastic resins and an array of the basic chemicals that support modern life. Tosoh’s petrochemical operations supply ethylene, polyethylene, and functional polymers, while its advanced materials business serves the global semiconductor, display, and solar industries. Tosoh has also pioneered sophisticated bioscience systems that are used for the monitoring of life-threatening diseases. In addition, Tosoh demonstrates its commitment to a sustainable future in part by manufacturing a variety of eco-products.

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Michael Hoover
International Corporate Development
Tosoh Corporation

Tel: +81-3-5427-5118
Fax: +81-3-5427-5198


For more information, please contact


Gina Lau
International Public Relations
Tosoh Corporation

[email protected]
Tel: +81 3 5427 5118
Fax: +81 3 5427 5198