Resumen: Ca3Co4O9 + xwt.% TiC (x = 0, 0.25, 0.5, 0.75, and 1.0) polycrystalline thermoelectric ceramics have been prepared through the classical ceramic route. XRD characterization has demonstrated that all samples are mainly composed by the Ca3Co4O9 phase, while microstructural observation has shown that no reaction between both components has been produced. Moreover, TiC particles are well distributed for small additions, and start to agglomerate from 0.75 wt.% content. Density measurements showed that nearly no changes have been produced by TiC addition and nearly the whole porosity appears as open one. Furthermore, electrical resistivity decreases up to 0.75 wt.% addition, increasing for higher content. On the other hand, Seebeck coefficient has been maintained unchanged in all samples. In spite of an irregular behaviour of thermal conductivity with temperature, it tends to decrease when the temperature is raised, displaying the lowest values for the 0.25 wt.% samples. These data led to an increase of about 40% in ZT values at 800 °C for samples with 0.25 wt.% addition, when compared with the pure ones. Finally, linear thermal expansion coefficient is decreased when TiC content is increased, which can be exploited to fit the thermal expansion coefficients of all the components used to build a power generation thermoelectric module. Idioma: Inglés DOI: 10.1016/j.bsecv.2020.03.006 Año: 2021 Publicado en: Boletin de la Sociedad Espanola de Ceramica y Vidrio 60, 3 (2021), 138-146 ISSN: 0366-3175 Factor impacto JCR: 3.483 (2021) Categ. JCR: MATERIALS SCIENCE, CERAMICS rank: 6 / 29 = 0.207 (2021) - Q1 - T1 Factor impacto CITESCORE: 4.3 - Materials Science (Q2) - Engineering (Q2)