Processing, spark plasma sintering, and mechanical behavior of alumina/titanium composites
This paper focuses on the study of the processing and mechanical properties, (flaw tolerance and R-curve behavior) of alumina–titanium ceramic–metal composites produced by spark plasma sintering. In order to obtain homogenously dispersed composites, a rheological study was carried out by measuring the flow behavior in different conditions of solid content, amount of dispersant and shear stress. It has been found that, with the suitable conditions (80 wt% solids and 3 wt% deflocculant), a ceramic–metal homogeneously dispersed (Al2O3–Ti) composite can be obtained. After sintering, the composites were mechanically tested and the cermet showed an important improvement in the flaw tolerance and R-curve behavior when compared with the monolithic material. It has been demonstrated by scanning electronic microscopy that this improvement is a consequence of the reinforcement mechanisms provided by the metallic particles that interact with the crack producing a notable increase in toughness up to ~8 MPa m1/2.
KeywordsSpark Plasma Sinter Crack Extension Metallic Particle Indentation Load Titanium Particle
This work was supported by the Spanish Ministry of Science and Innovation (MICINN) under the Project MAT2009-14542-C02-02 and by the Spanish Ministry of Economy and competitiveness (MINECO) under the Project MAT2012‐38645. E. Fernandez-Garcia acknowledges CSIC and ESF for the concession of a JAE-PreDoc 2010 grant. C.F. Gutierrez-Gonzalez acknowledges CSIC and ESF for the concession of a JAE-Doc 2009 grant.
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