Green Polyurethane Adhesive Bonding of Aluminum: Effect of Surface Treatments

2013 ◽  
Vol 393 ◽  
pp. 51-56 ◽  
Author(s):  
Norazwani Muhammad Zain ◽  
Sahrim H. Ahmad ◽  
Ernie Suzana Ali

Aluminum alloy 2024-T3 was treated by two different methods of surface treatments i.e. by alkaline etching and warm water treatment followed by silanization method in order to enhance the adhesive bonding. The effects of both the substrate surface condition and the adhesive properties on singlelap shear resistance were analysed. Three different formulation of polyurethane adhesive by varying the NCO:OH ratio which were prepared from polyol based on polycaprolactone (PCL)/palm kernel oil (PKO) with an aromatic and cycloaliphatic diisocyanate. Moreover, wettability tests were performed in order to evaluate the effect of all parameters mentioned above on the substrate/adhesive interaction. Surface treatment with warm water and ɣ-GPS gives better wettability and adhesive bonding compared to alkaline etching surface treatment.

Author(s):  
Gergely Juhász ◽  
Miklós Berczeli ◽  
Zoltán Weltsch

Over the last decade, the number of researches has increased in the field of bonding technologies. Researchers attempt to improve surface adhesion properties by surface treatments. Adhesive bonding is one of these bonding techniques, where it is important to see what surfaces will be bonded. One such surface property is wetting, which can be improved by several types of surface treatment. In recent years, atmospheric pressure plasmas have appeared, with which research is ongoing on surface treatments. In our research, we will deal with the effects of plasma surface treatment at atmospheric pressure and its measurement. In addition, we summarize the theoretical background of adhesion, surface tension and surface treatment with atmospheric pressure plasma. Our goal is to improve adhesion properties and thus the adhesion quality.


2004 ◽  
Vol 812 ◽  
Author(s):  
Thomas Abell ◽  
Jörg Schuhmacher ◽  
Youssef Travaly ◽  
Karen Maex

AbstractALD WNC nucleation and growth was observed strongly affected by different substrate materials and surface chemistries. Nucleation was inhibited on most pristine low k surfaces, which is attributed to low concentrations of chemisorption sites (Si-OH). Plasma treatments were used to alter the surface chemistry to improve nucleation. Surface closure and surface roughness of the WNC layer were found to strongly correlate with starting surface condition. Resistivities of the resulting films were also found dependent on starting surface treatment. But the relationship between W content of the films, surface treatment and resistivity was not fully comprehended.


The chapter presents the results of experimental research conducted by the author in the context of the possibility of introducing a change from traditional bonding technology to an unconventional one by means of laser surface treatment. The results of the analysis of the surface condition of the materials selected for this monograph were described, both in the so-called delivery condition (after rolling) and after traditional and laser surface treatment. The chapter also provides a comparison of the energy state of the surface to be glued after mechanical, chemical, and laser treatment. The results of bonding were shown in which static strength on the joint wall was taken as a criterion of evaluation. Additionally, unusual possibilities of lasers used to create specific surface roughness and useful in bonding operations were presented.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amr M. Elnaghy ◽  
Ayman Mandorah ◽  
Ali H. Hassan ◽  
Alaa Elshazli ◽  
Shaymaa Elsaka

Abstract Background To evaluate the effect of surface treatments on the push-out bond strength of Biodentine (BD) and white mineral trioxide aggregate (WMTA) to fiber posts. Methods Two brands of fiber posts were used: Reblida post; RP and RelyX post; RX. Each type of post (n = 80/group) was divided into four groups (n = 20/group) and exposed to surface treatment as follows: Control (no treatment), sandblasting (SB), hydrofluoric acid (HF), and TiF4 4 wt/v%. Each group was further subdivided into two subgroups (n = 10/subgroup) based on the type of CSCs used as follows: Subgroup A: BD and Subgroup B: WMTA. Push-out bond strength of BD and WMTA to glass fiber posts was assessed. Data were statistically analyzed using three-way ANOVA and Tukey’s test. A Weibull analysis was performed on the push-out bond strength data. Results BD showed higher bond strength than WMTA (P < 0.001). The push-out bond strength for posts treated with TiF4 4 wt/v% showed greater bond strength than the other surface treatments (P < 0.05). The BD/RP-TiF4 4 wt/v% showed the greater characteristic bond strength (σ0) (15.93) compared with the other groups. Surface treatments modified the surface topography of glass fiber posts. Conclusions The BD/RP-TiF4 4 wt/v% showed greater bond strength compared with the other groups. The TiF4 4 wt/v% surface treatment enhanced the bond strength of BD and WMTA to glass fiber posts than the other treatments. Surface treatment of fiber post with TiF4 4 wt/v% could be used to improve the bond strength with calcium silicate-based cements.


1991 ◽  
Vol 10 (6) ◽  
pp. 335-338 ◽  
Author(s):  
P. Davies ◽  
C. Courty ◽  
N. Xanthopoulos ◽  
H. -J. Mathieu

2020 ◽  
Vol 19 ◽  
pp. e206155
Author(s):  
Yançanã Luizy Gruber ◽  
Thaís Emanuelle Bakaus ◽  
Bruna Fortes Bittencourt ◽  
João Carlos Gomes ◽  
Alessandra Reis ◽  
...  

Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey’s post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values.


Author(s):  
V.Yu. Ulianitsky ◽  
J.A. Nikolaev ◽  
T.P. Gavrilenko ◽  
M.C. Kim ◽  
J.W. Hong

Abstract The role of surface roughness in coating adhesion mechanism is studying for detonation spraying. Roughness was produced by conventional grit blasting, D-gun blasting and was formed as a result of spraying of high-adhesive thin layer of detonation coating. Cermet and alloy powders were sprayed by detonation gun Ob. The coating bonding strength measurements show the WC+25Co adhesion to be above 200 MPa independently of a substrate surface preparation. Contrary, NiCrSiB coatings are very sensitive to surface conditions their adhesion varies from 180 MPa to zero. As-sprayed alloy particles fail in adherence because of insufficient energy to fuse substrate material at a flat surface. Only developed (wide scale) roughness may be fused partially by these particles for their bonding to the substrate. Otherwise, high heated cermet particles do not need special surface preparation (except cleaning) for fusion of substrate material to provide high bonding with it. The wide scale and ball shape roughness, which is similar to the self-reproduced coating roughness, provides the best conditions for the coating bonding and it is recommended as the purpose of surface treatment before thermal spray coating.


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