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Structure–Property Relationship in an Electroconductive Hydroxyapatite–Titanium Disilicide Composite
Author(s) -
Kumar Alok,
Misra R. Devesh Kumar,
Basu Bikramjit
Publication year - 2016
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.12553
Subject(s) - materials science , spark plasma sintering , fracture toughness , composite number , composite material , titanium , electrical resistivity and conductivity , sintering , conductivity , metallurgy , chemistry , electrical engineering , engineering
We elucidate here the structure–property relationship in a novel composite system consisting of hydroxyapatite ( HA ) and titanium disilicide that addresses the challenge of low electrical conductivity and fracture toughness of hydroxyapatite. Theoretical considerations indicated that the addition of 20 wt.% titanium disilicide (σ ~ 10 6 S/m) favorably contributed to the increase in electrical conductivity (σ ~ 10 5 S/m) of the HA –titanium disilicide system. As compared to theoretical value, a lower value of electrical conductivity of HA ‐20 wt.%TiSi 2 composite (σ ~ 67.117 ± 3.57 S/m) was observed in experimental measurement using four probe method. However, this electrical conductivity of HA ‐20 wt.%TiSi 2 composite was significantly higher than the HA , because no current was recorded in case of HA in the sensitivity range of the instrument. During spark plasma sintering, to raise per unit temperature, higher magnitude of current was utilized in case of HA ‐20TiSi 2 than HA . This resulted in higher densification of HA ‐20TiSi 2 during initial stage of sintering. Also, a significant improvement in fracture toughness was observed on the addition of TiSi 2 to HA from 0.6 MP a.m 1/2 in HA to 1.2 MP a.m 1/2 in HA ‐20TiSi 2 . The mechanism of increase in fracture toughness involved crack deflection, friction bridging, wake debonding, and elastic bridging.