Based in part on the thesis submitted by Shawn Madtha for the M.S. degree in the department of metallurgical engineering, The University of Utah, Salt Lake City, UT 84112.
Reactive-Sinter-Processing and Attractive Mechanical Properties of Bulk and Nanostructured Titanium Boride†
Article first published online: 4 OCT 2011
© 2011 The American Ceramic Society
Journal of the American Ceramic Society
Volume 95, Issue 1, pages 117–125, January 2012
How to Cite
Madtha, S., Ravi Chandran, K. S. (2012), Reactive-Sinter-Processing and Attractive Mechanical Properties of Bulk and Nanostructured Titanium Boride. Journal of the American Ceramic Society, 95: 117–125. doi: 10.1111/j.1551-2916.2011.04852.x
- Issue published online: 3 JAN 2012
- Article first published online: 4 OCT 2011
- Manuscript Accepted: 8 AUG 2011
- Manuscript Received: 23 FEB 2011
- State Center of Excellence for Titanium Boride Materials
- department of metallurgical engineering
- Governor's Office of Economic Development, the State of Utah, USA
An approach to synthesize bulk nanostructured titanium boride (TiB) ceramic material having a whisker-like microstructure with a very attractive combination of mechanical properties is presented. The material is made of a three-dimensional network of high aspect ratio TiB whiskers that are created in situ during reaction sintering of micron-sized component powders at pressures of 15–20 MPa and at relatively low temperatures (<1400°C). It is shown that the properties are sensitive to the amount of titanium used in the reaction-sintering process. The mechanism of formation of nanostructured TiB whiskers and the process of densification, both facilitated by tri-modal powder particle packing and liquid/β-phase regions, are illustrated. Mechanical property evaluations indicate that, unlike conventional nanoceramics, a good combination of hardness, strength, and toughness can be achieved by the control of microstructure. For example, the best TiB composition synthesized here resulted in a Vickers hardness of 16 GPa, an elastic modulus of 425 GPa, a mean flexural strength of 800 MPa, and a SEPB fracture toughness of 5.2 MPa√m. This combination of properties, from the perspective of room temperature applications, places the material on par with certain grades of silicon nitride (Si3N4) indicating that the material offers significant potential for further development.