Algorithms for microindentation measurement in automated Vickers hardness testing

2011 ◽  
Author(s):  
M. Gadermayr ◽  
A. Maier ◽  
A. Uhl
Keyword(s):  
Vickers Hardness ◽  
Hardness Testing

Substitution of Iron in Preparation of Enhanced Thermal Property and Bioactivity of Hydroxyapatite

2008 ◽  
Vol 55-57 ◽  
pp. 689-692 ◽  
Author(s):  
S. Meejoo ◽  
W. Pon-On ◽  
S. Charnchai ◽  
T. Amornsakchai
Keyword(s):  
Thermal Property ◽  
Vickers Hardness ◽  
Crystalline Phase ◽  
Vickers Microhardness ◽  
Experimental Methods ◽  
Hardness Testing ◽  
Thermal Behaviors ◽  
Carbonate Ions ◽  
Novel Material ◽  
Better Than

Incorporation of Iron into hydroxyapatite (HAp) has generated a novel material for which their properties differ from those of conventional HAp. Although XRD indicated that the as-prepared iron-substituted hydroxyapatite (HApFe) is of a single crystalline phase similar to that of HAp, we found that carbonate ions can incorporate in the HApFe structure 3 times better than in HAp. As results, HApFe possesses the Vickers microhardness about 1.5 times higher than that of HAp. Thermal behaviors and bioactivity of HApFe are discussed in comparison to those of HAp. Various experimental methods have been employed in this work including powder XRD, IR, SEM, DSC/TGA and Vickers Hardness testing.

scholarly journals Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods

2012 ◽  
Vol 3 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Farideh Bahrani ◽  
Mahroo Vojdani ◽  
Anahita Safari ◽  
Ghasem Karampoor
Keyword(s):  
Mechanical Property ◽  
Surface Roughness ◽  
Injection Molding ◽  
Vickers Hardness ◽  
T Test ◽  
Hardness Testing ◽  
Denture Base ◽  
Hardness Tester ◽  
Base Materials ◽  
Acrylic Resins

ABSTRACT Purpose The aim of this study was to evaluate mechanical property hardness and surface roughness (Ra) of different polymerization acrylic resins used for denture bases. Materials and methods A total of 30 specimens were prepared and divided in two groups. A total of 15 samples were processed by the compression molding technique using Meliodent (heatcured). Another 15 samples were processed with cold-cured resin Futura Gen via the injection molding technique. Hardness testing was conducted using a Vickers hardness tester. The Ra test was performed by a profilometer. Data were analyzed using the independent sample t-test and differences were statistically significant at the 0.05 level. Results The Vickers hardness numbers (VHN) were 20.8 ± 2.39 for Meliodent and 21.18 ± 1.42 for FuturaGen, which was not significantly different (p > 0.05). The Ra of Meliodent was 0.92 ± 0.23 µm and for FuturaGen it was 0.84 ± 0.37 µm. There were no significant changes in roughness. Conclusion The hardness and Ra of Meliodent and FuturaGen were not significantly different. Therefore, we recommend the use of FuturaGen for manufacturing denture base materials. How to cite this article Bahrani F, Safari A, Vojdani M, Karampoor G. Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods. World J Dent 2012;3(2):171-175.

Analysis of Load-Displacement Curves of Ceramics Measured with Low-Load Vickers Hardness Test: Indentation Size Effect

2011 ◽  
Vol 492 ◽  
pp. 9-13
Author(s):  
Bei Xu ◽  
Jiang Hong Gong
Keyword(s):  
Size Effect ◽  
Vickers Hardness ◽  
Indentation Size Effect ◽  
Hardness Test ◽  
Hardness Testing ◽  
Indentation Size ◽  
Nanoindentation Testing ◽  
Low Load ◽  
Load Displacement ◽  
Vickers Hardness Test

The load-displacement curves for a series of ceramic and glass samples were recorded continuously during the low-load Vickers hardness testing. Then the hardnesses of all samples were determined by analyzing the unloading curves. It was found that all the test materials exhibit indentation size effect (ISE) similar to that observed in nanoindentation testing. The applicability of the proportional specimen resistance (PSR) model and the modified PSR model was then examined using the measured indentation data.

Hardness Evaluation of Carbonate Apatite Cement Based on Various Ratio of Precursor

2017 ◽  
Vol 758 ◽  
pp. 52-55 ◽  
Author(s):  
Nina Djustiana ◽  
Mitha Amaranila ◽  
Nadia Greviana ◽  
Myrna Nurlatifah Zakaria ◽  
Sunarso ◽  
...  
Keyword(s):  
Vickers Hardness ◽  
Bone Substitute ◽  
Testing Machine ◽  
Control Group ◽  
Carbonate Apatite ◽  
Hardness Testing ◽  
Hardness Level ◽  
Natural Bone ◽  
Apatite Cement ◽  
Precursor Ratio

Carbonate Apatite (CO3Ap) cement is considered as an ideal bone substitute due to its biocompatibility and osteoconductivity. Also, CO3Ap cement has the chemical composition that closes to natural bone. During cement preparation, precursors play an important role that affects the properties of CO3Ap cement. Cement hardness is one of the important properties that need to be evaluated before the obtained cement can be applied as a bone substitute. Therefore, the purpose of this study is to determine the effect of precursor ratio of CaCO3 and CaHPO4 on the hardness level of CO3Ap cement. In the present study, the CO3Ap cement was prepared from CaCO3 and CaHPO4. Both Commercial and synthesized CaCO3 were used. The CO3Ap cement obtained from commercial CaCO3 was used as a control group. Synthesized CaCO3 was obtained from Indonesian natural limestone. Three different CaCO3:CaHPO4 ratios, 40:60, 30:70 and 20:80 were mixed with 1 mol/L Na2HPO4. Samples were kept at 37°C with 100% relative humidity for 24 hours then tested using micro Vickers hardness testing machine. The micro Vickers hardness of the control group with CaCO3:CaHPO4 ratio of 40:60, 30:70 and 20:80 were 5.09 VHN, 6.34 VHN, and 6.73 VHN, respectively. Meanwhile, the micro Vickers hardness of the CO3Ap cement obtained from synthesized CaCO3 were 6.22 VHN, 7.50 VHN, and 10.37 VHN for the CaCO3:CaHPO4 ratio of 40:60, 30:70 and 20:80, respectively. The micro Vickers hardness level of CO3Ap cement precursor ratio from the lowest to the highest was 40:60 < 30:70 < 20:80. In conclusion, the precursor ratio significantly affects the hardness level of the CO3Ap cement. The hardness level of CO3Ap cement obtained from synthesized CaCO3 was higher compared with that obtained from commercial CaCO3.

Sign in / Sign up

Export Citation Format

Share Document