The 21st KONA Award
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | KONA Powder and Particle Journal |
| Authors | Yoshio Sakka, Mr Hosokawa |
| Institutions | National Institute for Materials Science, Materials Processing (United States) |
Abstract
Section titled āAbstractāJournal of Inorganic Materials, Japan, and Journal of the Japan Society of Powder & Powder Metallurgy.Dr. Sakka has made outstanding contributions to science and technology of ceramic processing.He has successfully developed many types of nanoparticles, such as metal, ceramic, mixed, and composite particles, by a DCplasma method developed at NIMS.He has also developed new wet-chemical methods, such as the nano-explosion method, and a new sol-gel processing method by which several types of ceramic mono-dispersed particles have been prepared.In the processing of ceramics by sintering, well-dispersed fine powders are desirable not only to reduce the sintering temperature but also to obtain dense and fine-grained microstructures.By employing colloidal processing, Dr. Sakkaās group produced worldās first superplastic alumina, which can be elongated to over 550 %.Since this achievement they have produced several types of high-strain-rate superplastic ceramics.In addition, Dr. Sakkaās group succeeded in developing a new method for producing textured ceramics, in which the colloidal processing, such as by slip casting and electrophoretic deposition (EPD), is conducted under a strong magnetic field (c.a. 10 T).This method has several advantages and can be applied to many noncubic ceramics.They have fabricated many types of textured ceramics, such as Ī±-Al 2 O 3 , TiO 2 , ZnO, HAP, AlN, SiC, Ī²-Si 3 N 4 , MAX phase ceramics, Zr(Hf)B 2 , and B 4 C and showed the unique dependence of their properties on the crystalline plane.Ī²-Si 3 N 4 with high thermal conductivity of approximately 180 Wm -1 K -1 and the nacre-like structured Nb 4 AlC 3 with over 1000 MPa bending strength and 15 MPa.m 1/2 fracture toughness are typical examples.Furthermore, Dr. Sakkaās group developed novel sintering techniques, especially those based on the Spark Plasma Sintering (SPS).They used a combined modeling and experimental approach to clarify the relationship between the SPS parameters and the final properties.Highly transparent alumina, high-hardness B 4 C, diamond particles dispersed in pure WC, and superplastic ceramics of spinel and zirconia systems are typical examples of ceramics fabricated by SPS.So far,