scholarly journals Measurement of Bond Strength at Metal/Ceramic Interfaces

1989 ◽  
Vol 153 ◽  
Author(s):  
Gerald L. Nutt ◽  
William Lai ◽  
Kenneth E. Froeschner ◽  
Wayne E. King

AbstractWe report on a novel method for measuring the bond strength of metal/ceramic interfaces. Test specimens are created by vapor depositing a metal film on a ceramic substrate. The specimen is impacted with a thin metal flyer sending a short planar shock pulse into the ceramic. If the shape and amplitude of the wave is properly controlled the interface will spontaneously debond creating new free surfaces.Measurements indicate the debonding process occurs in less than 1.0 ns, which we believe is too short for crack propagation along existing flaws. Therefore, we conclude that simultanious breaking of atomic bonds rather than propagation and coalescence of cracks is the means by which the film and substrate are separated. The free surface velocity of the metal overlayer is monitored during spall by laser interferometry. The data constitute a direct measurement of the bond strength. The measured bond strengths are reproducible and do not show a dependence on shock amplitude for identically prepared specimens.

1989 ◽  
Vol 159 ◽  
Author(s):  
Gerald L. Nutt

ABSTRACTWe have reported bond strength measurements of metal/ceramic interfaces using shock waves to separate the bond by spallation[1,2]. The technique relies on the interpretation of the free surface velocity of the metal film as it is spalled from the substrate.We answer several questions relating to the details of the interaction of the shock with the interface. Specifically, we examine the role of sound speeds in the measurements. We also calculate the plastic strain in the the bond region and verify the theory relating to the jumpoff velocity of the scab to the bond strength.


2021 ◽  
pp. 232020682110371
Author(s):  
Emine Ünal ◽  
Faik Tugut

Aim: The aim of this study was to evaluate the effect of different cooling times on shear bond strength between cobalt–chromium metal frameworks fabricated by different techniques and veneering porcelain. Materials and Methods: One hundred twenty cobalt–chromium metal ceramic samples were obtained by three different techniques (casting, milling, and laser sintering). During the porcelain firing, fast and slow cooling protocols were applied. Ten specimens from each group were determined for all groups. The shear bond strength of the metal ceramic samples was measured by a universal testing machine with a constant crosshead speed of 0.5 mm/min. One sample from each group was evaluated by the scanning electron microscopy analysis in terms of surface change and fracture morphology. Variance analysis and Tukey test were used to analyze statistically significant differences between groups. Results: It was seen that the difference between the bond strengths of the metal frameworks obtained by different techniques was statistically significant ( P < .05). All groups except for difference between the bond strengths of all the frameworks metal groups with G-Ceram porcelain were statistically significant ( P < .05). The best bond strengths that were statistically significant were fast cooling G-Ceram (19.65 ± 2.65 MPa) with metal frameworks fabricated by laser sintering, fast cooling with metal framework fabricated by milling Noritake (19.17 ± 2.91 MPa), and the metal framework fabricated by casting was found to be slow cooling Noritake (12.99 ± 2.08 MPa) were seen. Conclusion: The porcelain cooling times had significant effect on the shear bond strength of porcelain to casting, milling and laser sintering alloys.


2003 ◽  
Vol 94 (3) ◽  
pp. 272-276 ◽  
Author(s):  
Amir Avishai ◽  
Christina Scheu ◽  
Wayne D. Kaplan

Author(s):  
Sílvia Fontes Do Amaral Pereira

O objetivo do presente estudo in vitro foi verificar, através de teste de cisalhamento, a resistência de união da liga Wironia®light, à base de níquel-cromo sem berílio, sujeita a diferentes tratamentos de superfície, às cerâmicas Vita VM13 e Noritake. Foram confeccionados oitenta espécimes cilíndricos metálicos, com o auxílio de uma matriz de aço, nas dimensões de 4 mm de diâmetro por 4 mm de altura. Os espécimes foram divididos em oito grupos (n=10), de acordo com o tipo de tratamento superficial aplicado à liga metálica e com o tipo de cerâmica testada. Estes foram avaliados de acordo com os critérios de resistência ao cisalhamento e, com o auxílio de microscopia óptica, foi avaliada a área de cerâmica remanescente aderida ao metal após a fratura. Os corpos-de-prova do G6 (fabricados em Cerâmica Noritake com jateamento-26,401 ± 11,637 MPa) apresentaram maior resistência ao cisalhamento (p> 0,05) enquanto que os menores valores foram registrados no G4 (Cerâmica Vita com utilização de broca-13,440 ± 7,766 MPa). G6 (19425,4 μm2) apresentou a maior área de cerâmica aderida ao metal (p> 0,05) enquanto que o G4 (2310,2 μm2) apresentou a menor área. Concluiu-se que G6 obteve os valores mais altos de resistência ao cisalhamento e de remanescente cerâmico aderido à superfície metálica enquanto que o G4 obteve os valores mais baixos. Descritores: Restaurações metalo-cerâmicas; ligas de níquel-cromo;porcelana dentária.


1991 ◽  
Vol 238 ◽  
Author(s):  
Young Keun Kim ◽  
Michael E. McHenry ◽  
Manuel P. Oliveria ◽  
Mark E. Eberhart

ABSTRACTA model based on the state-of-the-art, first-principles layer Korringa-Kohn-Rostoker (LKKR) method has proven to be very effective in describing the electronic and magnetic structure of metal/ceramic interfaces. We have performed self-consistent field computations incorporating spin polarization both for Fe/MgO superlattice (bulk technique) and for MgO/Fe/MgO sandwich (layer technique) systems. Muffin-tin potentials were employed for both materials in our computations. Iron layer was embedded in MgO, the host material, to have a [110](100)Fe / [100](100)MgO contact configuration. A large enhancement of magnetic moments has been found at the interface.


2014 ◽  
Vol 85 (4) ◽  
pp. 645-650 ◽  
Author(s):  
Laura Mews ◽  
Matthias Kern ◽  
Robert Ciesielski ◽  
Helge Fischer-Brandies ◽  
Bernd Koos

ABSTRACT Objective:  To examine differences in the shear bond strength of orthodontic brackets on differently mineralized enamel surfaces after applying a caries infiltrant or conventional adhesive. Materials and Methods:  A total of 320 bovine incisors were assigned to eight pretreated groups, and the shear force required for debonding was recorded. Residual adhesive was evaluated by light microscopy using the adhesive remnant index. Statistical analysis included Kolmogorov-Smirnov, analysis of variance (ANOVA), and Scheffé tests. Results:  The highest bond strength (18.8 ± 4.4 MPa) was obtained after use of the caries infiltrant. More residual adhesive and fewer enamel defects were observed on infiltrated enamel surfaces. Brackets on demineralized enamel produced multiple enamel defects. Conclusions:  Acceptable bond strengths were obtained with all material combinations. A caries-infiltrant applied before bracket fixation has a protective effect, especially on demineralized enamel.


2015 ◽  
Vol 26 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Mansour Rismanchian ◽  
Amin Davoudi ◽  
Elham Shadmehr

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.


2009 ◽  
Vol 03 (03) ◽  
pp. 173-177 ◽  
Author(s):  
Ahmet Yalcin Gungor ◽  
Hakan Turkkahraman ◽  
Necdet Adanir ◽  
Huseyin Alkis

ABSTRACTObjectives: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets.Methods: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI).Results: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis).Conclusions: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth. (Eur J Dent 2009;3:173-177)


Sign in / Sign up

Export Citation Format

Share Document