Probing the mechanical properties of dental porcelain through nanoindentation

Journal of the Mechanical Behavior of Materials

Aifantis Elias¹  Manda Marianthi²  Koidis Petros²  Konstantinidis Avraam³  Moschakis Nikolaos³  Christophilos Demetrios³  Papadopoulou Lambrini⁴ 

[1] ;School of Dentistry, Aristotle University, Thessaloniki 54124, Greece;School of Engineering, Aristotle University, Thessaloniki 54124, Greece;School of Geology, Aristotle University, Thessaloniki 54124, Greece;

关键词: dental porcelain;    micro-raman spectroscopy;    nanoindentation;    size effect;   

DOI  :  10.1515/jmbm-2012-0029

来源: DOAJ

【 摘 要 】

The purpose of this short communication is to report on some micro/nanoscale aspects of the mechanical behavior of dental porcelain. Specimens were characterized by micro-Raman spectroscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Massive nanoindentation experiments on the surface of the specimens were performed, and typical load-displacement or load-depth (P-h) curves were obtained, which in turn were used to determine the Young modulus (E) and nanoindentation hardness (n-H), based on the Oliver-Pharr method [1]. Statistical analyses were carried out to determine the Spearman’s rank correlation coefficient (Spearman’s ρ), along with non-parametric linear regression analysis by employing Kolmogorov-Smirnov and Two-Step Cluster tests. Densification due to grain boundary diffusion and open-pore elimination was revealed by SEM. EDS analysis indicated a leucite-dispersed silicate glass matrix, as well as its contamination by traces of other minerals. Raman spectroscopy supported the EDS assignments. The P-h curves suggested that inelastic deformation and material flow increases at larger depths. Spearman’s ρ value showed strong dependence of E and n-H on h, indicating the occurrence of a size effect. The logarithmic data of E and n-H as functions of h were fitted by using linear regression analysis. The data did not obey a normal distribution (as the Kolmogorov-Smirnov test showed) due to the chemical heterogeneity involved. The Two-Step Cluster analysis indicated clustering in four groups associated with the chemical heterogeneity of the surface. Similar works using nanoindentation to determine the mechanical properties of dental materials can be found, for example, in [2, 3]. Corresponding methods for extracting the values of E and n-H from P-h experimental curves can be found, for example, in [4–6].

【 授权许可】

Unknown