| Texto completo | |
| Autor(es): |
Daguano, Juliana K. M. B.
[1, 2]
;
Dantas, Lais
[3]
;
Soares, Viviane O.
[3]
;
Alves, Manuel F. R. P.
[4]
;
dos Santos, Claudinei
[4]
;
Zanotto, Edgar D.
[3]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Ctr Informat Technol Renato Archer, Campinas, SP - Brazil
[2] Fed Univ ABC, Ctr Engn Modeling & Appl Social Sci, Sao Bernardo Do Campo, SP - Brazil
[3] Univ Fed Sao Carlos, Mat Engn Dept, Vitreous Mat Lab, Sao Carlos, SP - Brazil
[4] Univ Estado Rio De Janeiro, Fac Technol, Mat & Proc Lab, Resende, RJ - Brazil
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS; v. 122, OCT 2021. |
| Citações Web of Science: | 0 |
| Resumo | |
Objectives: This study aimed to optimize the crystallization process and the microstructure of a new bioactive glass-ceramic (GC) previously developed by our research group to obtain machinable glass-ceramics. Methods: Differential scanning calorimetry (DSC) analyses were conducted to explore the characteristic temperatures and construct a semi-quantitative nucleation curve. The GC specimens were characterized by X-ray diffraction (XRD) and Rietveld refinement. Their brittleness index (B) and machinability were characterized and compared with IPS e.max-CAD (R). Their Young's modulus, fracture toughness, and hardness were assessed. Results: We found that the maximum crystal nucleation rate temperature of this GC is similar to 470 degrees C. Treatments were designed based on the 1st DSC peak onset (570 degrees C), 1st peak offset (650 degrees C), and 2nd peak offset (705 degrees C) crystallization temperatures of lithium metasilicate (LS, LiSi2O3) and lithium disilicate (LS2, Li2Si2O5). Rietveld refinement indicated an increase in LS2 and a reduction in LS and amorphous phase for increased temperatures and longer treatment times. Their B values indicate good machinability compared with that of the control group based on statistical analyses. As expected, lower levels of LS2 increase the machinability regardless of the rotation speed adopted, leading to a greater depth of cut and reduced Edge Chipping Damage Depth (ECDD). Conclusion: This bioactive GC with optimized microstructure presents high machinability. For treatment temperatures above 570 degrees C, the number of elongated LS2 crystals increases and decreases the amorphous phase content, which reduce the machinability of the GC, and should therefore be avoided. The best results were obtained using heat treatment at 570 degrees C, which produces LS crystals embedded in a glassy matrix (67%) with small contents of secondary phases. (AU) | |
| Processo FAPESP: | 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros |
| Beneficiário: | Edgar Dutra Zanotto |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |