| Title | Densification route and mechanical properties of Si 3N
4-bioglass biocomposites
|
| Publication Type | Journal Article |
| 2002 |
| Authors | Amaral, M, Lopes, MA, Silva, RF, Santos, JD |
| Journal | BiomaterialsBiomaterials |
| Volume | 23 |
| Issue | 3 |
| Pagination | 857 - 862 |
| Date Published | 2002/// |
| 01429612 (ISSN) |
| 3N, 4-bioglass composites, article, Bending strength, Biocompatible Materials, biomaterial, Biomaterial composites, Biomaterials, Ceramic materials, ceramics, Composite Resins, Crystallization, Densification, Densification behaviour, density, Elastic moduli, Fracture toughness, glass, hardness, heat, Hot pressing, Hot-pressing, Kinetics, Mechanical properties, phase transition, Phase transitions, priority journal, Si, Silicon compounds, silicon derivative, Sintering, strength, Stress, Mechanical, technique, Thermodynamics, Vickers hardness testing, X-Ray Diffraction, young modulus |
| The processing route and the final microstructural and mechanical characteristics of a novel biomaterial composite are described. This new material is composed of 70 wt% Si 3N
4 ceramic phase and 30 wt% bioglass, the later performing as a liquid sintering aid system and simultaneously providing bioactivity characteristics to the composite. The conditions for fabrication of an almost fully dense material (∼98% of relative density) were pursued. Optimised parameters were 1350°C-40min-30 MPa by hot-pressing technique. The very fast densification rate of the process avoided the crystallisation of the bioglass intergranular phase and therefore its intrinsic properties were maintained. Also, the large amount of glassy phase assured the densification by liquid phase assisted grain rearrangement without Si
3N
4 phase transformation. The final mechanical properties of the Si
3N
4-bioglass were as follows: fracture toughness, K
IC = 4.4 MPa m
1/2; Vickers hardness, H
V = 10.3 GPa; Young's modulus, E = 197 GPa; bending strength, σ
R = 383 MPa; Weibull modulus, m = 8.3. These values provide an attractive set of properties among other bioactive materials, namely by upgrading the main drawback of bioceramics and bioglasses for high-load medical applications, which is the lack of satisfactory fracture toughness. © 2001 Elsevier Science Ltd. All rights reserved.
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