Effects of carbon black content on the microstructure and properties of carbon/ceramic conductive composites

Abstract

Carbon/ceramic conductive composites have been widely used in many fields such as aerospace, industrial heating and health care due to the excellent characteristics of the ceramic matrix and carbon-based conductive fillers. In this paper, carbon/ceramic conductive composites were prepared with a ceramic matrix (albite, diopside and quartz) and carbon-black (CB) conductive filler, and the effects of the CB content on the phase composition, microstructure, sintering performance, mechanical and electrical properties of the composites were studied. The results showed that CB particles entered the pores among the ceramics particles when the CB content increased from 0 w/% to 5 w/%, accompanied with a degradation of the porosity, water absorption, sintering performance and electrical conductivity but an enhancement of the mechanical properties. With a further increase in the CB content, the number of the CB particles on the surfaces of the ceramic particles was increased and the porosity began to increase while the mechanical properties were degraded. During the increase in the CB content, there was little variation in the sintering properties but the electronic conductivity decreased a lot.Kompoziti ogljik/keramika s kerami~no matrico in prevodnim polnilom se danes zaradi odli~nih lastnosti uporabljajo na mnogih podro~jih, kot so letalske in vesoljske tehnologije, industrijsko ogrevanje in zdravstvo. Avtorji opisujejo pripravo prevodnih kompozitov s kerami~no matrico (albit, diopsid in kvarz) in prevodnim polnilom iz~rnega ogljika (CB, angl:: carbon black). Raziskovali so vpliv vsebnosti CB na fazno sestavo, mikrostrukturo, sinterabilnost, mehanske in elektri~ne lastnosti izdelanih kompozitov. Rezultati preiskav so pokazali, da se CB delci nahajajo v porah med kerami~nimi delci, ko vsebnost CB delcev naraste z 0 na 5 masnih dele`ev. To zmanj{a poroznost, absorpcijo vode, sinterabilnost in elektri~no prevodnost, a izbolj{a mehanske lastnosti kompozita. Z nadaljnjim pove~evanjem vsebnosti CB se pove~uje {tevilo CB delcev na povr{ini kerami~nih delcev, poroznost nara{~a in mehanske lastnosti se poslab{ajo. S pove~evanjem vsebnosti delcev se le malo spremeni sinterabilnost, elektronska prevodnost pa se mo~no zmanj{a. Klju~ne besede: prevodni kompoziti ogljik/keramika, vsebnost~rnega ogljika, mikrostruktura, lastnosti