Effect Of Different Surface Treatments Research Articles

Evaluation of Surface Treatment for Enhancing Adhesion at the Metal-Composite Interface in Fibre Metal-Laminates.

The paper presents the issues of metal surface treatment in fibre metal laminates (FML) to obtain high adhesion at the metal–composite interface. Aluminium 2024-T3 and titanium Grade 2 were analysed. The metal surface modifications were carried out by mechanical (sandblasting, Scotch-Brite abrasion), chemical (P2 etching, phosphate-fluoride process), electrochemical (chromic and sulphuric acid anodizing), and plasma treatment, as well as the application of sol-gel coatings. In terms of surface geometry, the analysis included roughness and 3D surface topography examination. The morphology was examined using scanning electron and atomic force microscopy. The surface free energy and its components (polar and dispersive) were determined using the Owens–Wendt method. The novelty of this study is the determination of the effect of different surface treatments on the surface free energy, topography, and morphology in terms of the possible appropriate adhesion in fibre metal laminates. Chromic acid anodizing is still the most effective in enhancing the expected adhesion. A suitable technique may be the use of P2 etching of aluminium. It results in low roughness, numerous micro-irregularities, and the presence of porosity. The obtained test results show that the application of sol-gel coating increases the surface free energy and may increase the adhesion.

Effect of Different Surface Treatments and Repair Materials on Shear Bond Strength of Bulk-Fill Resin Composite

Effect of Different Surface Treatments and Repair Materials on Shear Bond Strength of Bulk-Fill Resin Composite

Effect of Sandblasting with Fluorapatite Glass-ceramic Powder and Chemical Primers/Adhesives on Shear Bond Strength of Indirect Repairing Composite to Zirconia.

To investigate the effect of sandblasting with fluorapatite glass-ceramic (FGC) powder on zirconia surface roughness, crystallinity, and shear bond strength (SBS) of indirect repairing composite to zirconia using different primers/adhesives. Zirconia blocks were treated as follows: no treatment (control group), blasting with 30-μm silica-coated alumina (CoJet group), and blasting with FGC powder (FGC group). The surface topography, silica content, roughness, and crystallinity of treated zirconia surfaces were analyzed by a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), an optical profilometer, and X-ray diffraction (XRD), respectively. Four primers/adhesives (Monobond Plus, Calibra Silane, Futurabond M+, and Scotchbond Universal) were compared to bond precured resin composite to zirconia groups using Multilink Automix resin cement. Bonded specimens were thermocycled for 10,000 cycles and tested in SBS and the modes of failure were recorded. The effect of different surface treatments and primers/adhesives on SBS results were statistically analyzed using two-way ANOVA and Bonferroni post-hoc tests (α=0.05). Both CoJet and FGC groups showed rough surfaces with a higher content of silica in FGC, but less monoclinic crystals, compared to the CoJet group. The highest mean SBS was found in the FGC group treated with Monobond Plus compared to CoJet and Control groups. Adhesive failure was predominant in control groups, while combined failure was found in the CoJet and FGC groups regardless of the primers/adhesives employed. Sandblasting zirconia with FGC powder increased SBS of resin composite to zirconia with lower monoclinic phase transformation compared to CoJet sand. Monobond Plus reported the highest means of SBS values compared to other primers/adhesives.

Effects of different surface treatments on the compression-shear strength of CAD-CAM zirconia posts

Aim: Post systems are crucial for the treatment of endodontically treated teeth with excessive crown destruction. Currently, increase in esthetic demands has increased the use of tooth-colored post systems. The aim of this study was to evaluate compression-shear strength after the application of different resin cements and different surface treatments to zirconia post-cores produced by the CAD-CAM milling technique. Methodology: One hundred twenty crown parts of maxillary central incisors were cut using a 2-mm enamel–cement joint using a water-cooled diamond bur in an air turbine handpiece at 300,000 rpm. Root canals with the same diameter were prepared using Gates-Glidden drills and Snowpost system drills. According to the enlarged canal, zirconia posts were prepared by the CAD-CAM copy-milling technique, and the zirconia post surfaces were roughened by different techniques (hydrofluoric acid, Al2O3 partial abrasion, CoJet silica coating). The roughened posts were cemented to the tooth canal using three resin cements: 10-Methacryloyloxydecyl dihydrogen phosphate (MDP)-containing cement, Bis-GMA-based resin, and resin-based adhesive. As the control group, the zirconia post surfaces with no application were fixed using three resin cements. The specimens were set down into 25x25x25 mm fabricated blocks with acrylic resin materials. Compression-shear strength tests of the prepared samples were conducted on the Instron Testing Machine by using appropriate equipment. Results: In summary, the combination of roughening techniques such as Al2O3 partial etching and CoJet silica coating using cement-containing MDP rendered the highest compression-shear strength. Conclusion: This in vitro study proposes the cementation of zirconia post-cores etched by Cojet silica coating and Al2O3 particles using MDP-containing resin cement. How to cite this article: Eskitaşçıoğlu M, Toprak Gündüz D, Seyfioğlu Polat Z, Göncü Başaran E, Ayna E. Effects of different surface treatments on the compression-shear strength of CAD-CAM zirconia posts. Int Dent Res 2022;12(2):55-61. https://doi.org/10.5577/intdentres.2022.vol12.no2.a3 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of Surface Roughness and Color Stability of Different Denture Characterizing Composite Resins: The Effect of Different Surface Treatments.

This study aimed to investigate the effect of surface treatment and type of composite resin material on the color stability and surface roughness of different denture characterizing composites. Two nanohybrids [Gradia Plus Gum, (GP) and SR Nexco Paste Gingiva, (SR)] and one microhybrid gingiva-colored composite resin [Amaris Gingiva, (AG)] were investigated. A total of 120 disk-shaped samples were prepared, 40 of each material. Samples were divided into two groups (n = 20) for each material according to the surface treatmentapplied: conventional polishing (control) and coated with a sealant in addition to the surface polishing. All groups were thermocycled. The surface roughness (Ra) was measured using a profilometer after thermal cycling. The samples were then divided into 2 subgroups (n = 10) and stored for 7 days in distilled water or coffee solution. Color differences (ΔE00 ) were calculated with a spectrophotometer. Results were evaluated with Kruskal-Wallis and Mann-Whitney U statistical analysis. The type of denture characterizing composite material and surface treatment method revealed statistically significant differences for the ΔE00 (after immersion both in coffee and distilled water) and the Ra values of denture characterizing composite (p < 0.001 for both). All sealed groups showed significantly higher Ra than the all polished groups. Both in the polished groups and the sealant applied groups, the GP had the highest mean Ra values (0.29 ±0.05μm and 0.47 ±0.09μm, respectively). It was followed by SR (0.23 ±0.06μm and 0.41 ±0.10μm, respectively), and AG groups (0.20 ±0.06μm and 0.39 ±0.09μm, respectively). According to the mean ΔE00 results, all composite groups showed significantly higher ΔE00 values immersed in coffee solutions compared to distilled water. In coffee solutions, the highest ΔE00 was observed in the polished GP (1.90 ±0.40), and the lowest ΔE00 was observed in the polished SR (0.97 ±0.36). The sealed groups showed higher ΔE00 than the polished groups, except for GP. The surface roughness value of sealant applied groups were significantly higher than those of the polished groups. The surface sealant applicationsignificantly increased the staining of all composite groups compared to conventional polishing, except for GP.

Effect of heating antioxidants and delayed bonding on bond strength to bleached enamel

Objective: The aim of this study was to evaluate the influence of heating natural antioxidants on their antioxidant activity and on micro shear bond strength of composite resin to bleached enamel. Materials and methods. A hundred-eighty flowable composite cylindrical specimens of 0.8 mm diameter and 1 mm length were bonded to enamel substrate for microshear bond strength evaluation. Six study groups were created (n=30). Group 1: No bleaching, Group 2: Bleaching only, Group 3: Bleaching+ Pine Bark Extract at Room temperature, Group 4: Bleaching + Pine Bark Extract preheated to 60° C. Group 5: Bleaching+ Grape Seed Extract at Room temperature, Group 6: Bleaching+ Grape Seed Extract preheated to 60° C. All groups were tested immediately (subgroup a), after one week (subgroup b) and two weeks (subgroup c). Both extracts were tested for their antioxidant activity using DPPH assay at room temperature, 40° and 60°. Two- and one- way ANOVA were used to explore the effect of different surface treatments and bonding time on microshear bond strength. Results. DPPH results showed the heated antioxidant extracts to have significantly higher antioxidant activity than their non-heated counterparts.

Effect of Different Surface Treatments of 42CrMo Steel Piston Rod on its Corrosion Resistance in Sodium Chloride Solution

Effect of Different Surface Treatments of 42CrMo Steel Piston Rod on its Corrosion Resistance in Sodium Chloride Solution

Effect of different surface treatments on the bonding potential and physical and mechanical properties of ultratranslucent zirconia

Statement of problemStudies to determine a suitable surface treatment that improves bonding without compromising the strength or translucency of ultratranslucent zirconia are scarce. PurposeThe purpose of this in vitro study was to evaluate the effect of different surface treatments on translucency, surface topography, phase transformation, biaxial flexural strength, bond strength, and durability. Material and methodsA total of 169 ultratranslucent zirconia disks were randomly divided into 4 groups according to the surface treatment applied: airborne-particle abrasion (APA) (n=46), tribochemical silica airborne-particle abrasion (TS) (n=46), nonthermal oxygen plasma (NTP) (n=46), and no treatment, control (C) (n=31). The translucency parameter (ΔTP00) was evaluated with a spectrophotometer (n=15), phase transformation was assessed with an X-ray diffractometer (n=5), surface topography was evaluated with a scanning electron microscope (SEM) (n=3), and biaxial flexural strength (BFS) was tested with a universal testing machine (n=15). For the microshear bond strength (μSBS) test, 40 composite resin specimens were attached to 8 disks and tested with a universal testing machine; 20 specimens were tested after 24 hours, and 20 specimens after hydrothermal aging in a thermocycler (TC). The data were analyzed with ANOVA followed by the Tukey post hoc test (α=.05). Weibull analysis was performed for the flexural strength and μSBS results. ResultsSignificant ΔTP00 differences were found among all groups and were highest for the APA group (7.33) and lowest for the NTP group (4.79). The NTP group had a significantly higher monoclinic weight fraction value (4.54%) than other groups. The NTP group had significantly higher BFS (581.31) than other groups, while the APA group showed significantly lower values than other groups (340.43). The APA group had significantly higher μSBS values after 24 hours (13.51 MPa) and after TC (13.68 MPa) than the other groups (P<.05). ConclusionsAlthough APA and TS are effective techniques for improving resin-zirconia bonding, they result in significantly higher deterioration of translucency and strength. NTP significantly improved the BFS of zirconia; however, it showed lower bond strength values than other methods.

Surface Treatments on Repair Bond Strength of Aged Resin Composites.

ABSTRACTAims:The aim was to evaluate the effect of different surface treatments on the repair shear bond strength of aged resin composites.Materials and Methods:Forty cylindrical-shaped specimens were treated from each material: Tetric Evo Ceram, Neo Spectra, and Filtek Ultimate Universal Restorative and allocated into four groups according to the surface treatment planned to use: Group 1: diamond, Group 2: silica coating, Group 3: carbide burs, and Group 4: control group. Following the surface treatment, composites were repaired with flowable resins. The shear bond strength was tested using a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture mode was assessed under 50× magnification. The data were analyzed statistically using a two-way analysis of variance (ANOVA) test followed by a one-way ANOVA test. Multiple comparison procedures were performed using Tukey’s test. The level of significance was set at P < 0.05.Results:The lowest mean value of the shear bond strength was for the Filtek Ultimate Universal Restorative in the control group, whereas the highest mean value was in the silica group. Silica and carbide groups had significantly higher mean values of the shear bond strength than diamond and control groups in Tetric EvoCeram and Filtek Ultimate Universal Restorative. In contrast, in Neo Spectra St HV, the carbide group had a higher mean value but was not statistically significant.Conclusion:Combinations of mechanical and chemical retentive systems enhance the shear bond strength of the repair composite to the aged composite. Among the different surface treatments employed in this study, silica and carbide groups show higher repair bond strength of new composite to aged composite.

Effect of Different Surface Treatments and Orthodontic Bracket Type on Shear Bond Strength of High-Translucent Zirconia: An In Vitro Study.

Objective Considering the increasing number of adults seeking orthodontic treatment, and the possible need for bracket bonding to monolithic zirconia restorations, knowledge about the preferred type of bracket (metal/ceramic) and the most efficient surface treatment is imperative to achieve acceptable shear bond strength (SBS). This study aimed to assess the effect of different surface treatments and orthodontic bracket types on SBS of high-translucent zirconia. Materials and Methods Totally, 248 disc-shaped zirconia specimens were assigned to two groups for bonding to metal and ceramic brackets. Each group was divided into four subgroups (n = 31) for the following surface treatments: no surface treatment (control group), airborne-particle abrasion (APA), tribochemical silica coating with CoJet, and CO2 laser irradiation. The mean surface roughness (Ra value) was measured. The SBS was measured after bracket bonding and thermocycling. Data were analyzed by two-way ANOVA, Tukey, Kruskal–Wallis, Mann–Whitney, and Fisher exact tests, and Bonferroni correction (α=0.05). Results The mean Ra value was significantly different among the surface treatment subgroups (P < 0.001). The APA and CoJet subgroups were not significantly different regarding Ra (P=0.754). All other pairwise comparisons yielded significant differences (P < 0.001). Bracket type, surface treatment, and their interaction significantly affected the SBS (P < 0.001). Ceramic brackets bonded to zirconia surfaces treated with CoJet yielded the maximum SBS while ceramic brackets bonded to control and lased surfaces resulted in minimum SBS. No significant difference was noted in the SBS of different surface treatment groups when metal brackets were used (P > 0.05). Conclusions The use of ceramic brackets and CoJet surface treatment would be the most appropriate combination to achieve optimal bonding to high-translucent zirconia restorations.

Effect of different surface treatments and thermomechanical aging on the ion elution of CAD-CAM materials

Statement of problemDental ceramics have been reported to elute ions when subjected to nonneutral pH. However, the effect of surface treatments and thermomechanical aging on the ion elution of CAD-CAM ceramics is unclear. PurposeThe purpose of this in vitro study was to compare the effect of surface treatment (glazed or polished) and thermomechanical aging on the ion elution of CAD-CAM materials before and after 2-body wear simulation. Material and methodsSpecimens were prepared from 6 CAD-CAM materials—leucite (LC), feldspathic (FP), zirconia-reinforced lithium silicate (ZLS), lithium disilicate (LDS) glass-ceramics, polymer-infiltrated ceramic network (PICN), and zirconia (ZIR)—and divided into 2 groups according to the surface treatments (glazed or polished) (n=6). For baseline ion elution values, specimens were placed into polyethylene bottles containing deionized water (pH 7.4) that had been stored in an incubator for 168 hours at 37 °C. The eluted ions in the immersion solution were measured by using inductively coupled plasma-optic emission spectrophotometry. The specimens were then subjected to thermomechanical aging by using human enamel as an antagonist. After aging, the ion elution of the specimens was remeasured. Ion elution data before and after 2-body wear were analyzed by using the Mann-Whitney U test, while the effect of 2-body wear was assessed by using the Wilcoxon signed rank test (α=.05). ResultsThe presence of some ions varied depending on the material-surface treatment pair before (Al, As, B, Ba, Ca, K, Li, Mg, Na, P, and Zn) and after (Al, B, Ba, Ca, Co, Li, Mg, and P) 2-body wear. Polished materials had higher ion elution than the glazed materials before 2-body wear (P≤.041), except for LC (P and Zn) and PICN (Ca, Cu, and K) (P≤.009). After 2-body wear, polished LC (B and Ba), FP (Al, B, and Mg), ZLS (Al, Ba, Ca, and Li), ZIR (B and Ba), glazed PICN (Ca, Mg, and P), ZLS (P), and ZIR (Co) presented higher ion elution than their counterparts (P≤.041). The effect of 2-body wear on the ion elution of polished LC (Al, K), FP (Na), ZLS (Li), LDS (K, Na), PICN (Al, Na), ZIR (Na, Y), glazed LC (Na), FP (Ba, Na), ZLS (B, Ba, Y), LDS (Na), PICN (Y), and ZIR (Na) was nonsignificant (P≥.075). However, the elution of remaining ions showed a significant difference before and after 2-body wear (P≤.046). ConclusionsThe chemical stability of tested CAD-CAM materials was affected by the 2-body wear. Glazing led to a lower ion elution except for LDS and PICN. While polishing resulted in lower ion elution for PICN, both surface treatments resulted in similar ion elution for LDS.

Effect of different surface treatments on the micro tensile bond strength to dentin, biaxial flexural strength and roughness of CAD/CAM resin composite and polymer infiltrated ceramic

ObjectivesTo evaluate the biaxial flexural strength (BFS), surface roughness (Ra) and micro tensile bond strength (μTBS) of two CAD/CAM materials after different surface treatments. Materials and methodsFor μTBS, 64 human molars were used and 32 blocks of resin composite (RC-Lava Ultimate) and polymer-infiltrated ceramic (PIC -Vita Enamic). The blocks and teeth were distributed into 16 groups according to the factors “surface treatment” (HF: 10% hydrofluoric acid; APA: Al2O3 sandblasting; SC: silicate-Al2O3 sandblasting; MEP: Monobond Etch and Prime) and “thermal cycling” (TC). After cementation, the blocks were sectioned into 1 mm2 bars. Half of the specimens were thermocycled and submitted to μTBS test. For BFS, RC and PIC discs were made and distributed according to the surface treatments and after mechanical cycling, submitted to BFS test. Roughness, EDS, SEM, and Weibull analyses were also performed. Data were analyzed by (1 or 2-way) ANOVA and Tukey test (α = 0.05). ResultsFor RC, SC and HF after TC showed significantly higher μTBS values. For PIC HF after TC showed higher μTBS than the other groups. For RC, the BFS was higher for MEP than Al2O3 and SC. For PIC, none of the surface treatments influenced BFS. ConclusionThe highest μTBS for RC was obtained with SC followed by silanization and for PIC, HF followed by silanization. The RC showed lower strength after Al2O3 blasting. For PIC all surface treatments resulted in similar BFS.

Study on the interface bond strength of DP780 steel/CFRP composite laminate based on hot-press curing integration

The metal and carbon fiber reinforced plastic (CFRP) hybrid parts are increasingly used in automobile industry to meet the demand for vehicle weight reduction. The interface bond strength between metal and CFRP is the key to the part properties. The effects of different surface treatments on the interface bond strength of DP780 Steel/CFRP composite laminate based on hot-press curing integration were studied. Single lap test and single-leg bending (SLB) test were used to characterize the interface bond strength of the hybrid composite laminate. Interface failure mechanism was analyzed through surface roughness, fracture mode and fracture morphology. The experimental results showed that the steel surface treated by laser exhibited the highest surface roughness and the greatest surface energy in contrast to other surface treatments, such as degreasing, acid corrosion and grinding. The single lap test results showed that the laser-treated specimen had the maximum interface bond strength and there were a lot of fibers residues on the steel fracture surface. In SLB tests, there was no gap between the laser-treated steel and CFRP interface. The interface was bonded finely, which greatly improved the interface bond strength.

Effect of Different Surface Treatments on the Micro-Shear Bond Strength and Surface Characteristics of Zirconia: An In Vitro Study.

Purpose To study the effect of different surface treatments on the micro-shear bond strength and surface characteristics of zirconia. Methods Two types of zirconia ceramics were tested: opaque (O) and translucent (T). Each type of zirconia was further allotted into four groups based on the type of surface treatment method. The four groups were: control (C), air abrasion with 110 µm Al2O3 particles (A), etching with Zircos–E Etching solution for 2 hours (E), and a combination of air abrasion and etching (AE). After the surface treatment, all specimens were ultrasonically cleaned and 10 resin cement cylinders were attached to the zirconia discs in each group. A micro-shear bond strength test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture surfaces were assessed under a compound microscope. SEM, EDAX, and AFM analyses were done for the zirconia specimens after being subjected to surface treatment. Statistical analysis for the bond strength test was done using the Shapiro–Wilk test, one-way analysis of variance (ANOVA), and Post hoc Tukey test. Results The micro-shear bond strength values for the groups were as follows in megapascals (MPa): OC 18.96 (5.54), OA 22.66 (2.51), OE 28.48 (4.50), OAE 28.63 (4.53), TC 22.82 (5.46), TA 25.36 (5.17), TE 28.12 (4.76), and TAE 32.00 (3.47). The one-way analysis of variance (ANOVA) and post hoc Tukey HSD tests were done which showed significant results in the groups. In opaque zirconia, significant differences were seen in the etching and air abrasion with etching groups when compared with the control and air abrasion groups. There was no difference between the etching and air abrasion with etching groups. For translucent zirconia, the only significant difference was seen in the air abrasion with etching group in comparison with the control and air abrasion groups. The mode of failure was majorly adhesive. The surface topography and surface roughness showed significant differences between the groups. The EDAX results showed material loss that occurred due to sandblasting in the air abrasion groups. Conclusions Etching with Zircos–E Etching solution significantly increased the bond strength of zirconia to resin cement when compared with other surface treatment methods. In translucent zirconia, the best results can be achieved by combining etching with air abrasion.

Effect of different surface treatments on color stability of ultra-translucent zirconia occlusal veneers before and after thermocycling aging

Effect of different surface treatments on color stability of ultra-translucent zirconia occlusal veneers before and after thermocycling aging

Corrosion behaviour of the 2098-T351 Al–Cu–Li alloy after different surface treatments

ABSTRACT The effect of different surface treatments on the corrosion resistance of the AA2098 Al–Cu–Li alloy has been investigated. Surface characterization was performed using 3D optical profilometry, energy dispersive X-ray spectroscopy and scanning electron microscopy. The corrosion resistance of the 2098 alloy after the surface treatments was investigated in 0.1 mol L−1 NaCl solution by electrochemical techniques and microscopy. Corrosion results showed that the untreated and the chemically etched surfaces were more active than the mechanically abraded and mechanically polished surfaces owing to differences in the nature of the native oxides formed after the surface treatments. Corrosion rate and mode were also affected by how close the exposed surface was to the mid-thickness region of the AA2098-T351 plate relative to the actual top surface (before polishing). This is associated with the variation in the volume fraction and distribution of the T1 phase as the mid-thickness region of the AA2098-T351 plate is approached.

Effect of different surface treatments on the microhardness and colour change of artificial enamel lesions.

To investigate the effect of three different surface treatments on the microhardness and colour change of artificial enamel lesions. One hundred bovine teeth were randomly assigned into four groups. Artificial enamel lesions were created using demineralizing solution for all groups except the sound enamel group. Different surface treatments were then performed G1: resin-infiltrant; G2: Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); G3: artificial saliva; G4: Sound Enamel. Each group was subdivided into three subgroups, where each subgroup was subjected to a different testing method. Subgroup 1: surface microhardness; subgroup 2: cross-sectional microhardness; subgroup 3: colour measurement. Statistical analysis was performed by ANOVA, followed by Tukey's post hoc test. Sound enamel group recorded the highest surface and cross-sectional microhardness results. No significant difference was found between the resin-infiltrant group and CPP-ACP regarding surface and cross-sectional microhardness at different lesion depths. Resin-infiltrant group showed the least colour change (∆E) results compared to the other groups. Resin-infiltrant can effectively enhance surface microhardness and enamel resistance to demineralization, additionally, reduces the staining susceptibility of white spot lesions (WSLs) after treatment. CPP-ACP application for 4 weeks seems to improve surface microhardness; however, has a limited effect in resisting staining of WSLs after treatment. © 2022 Australian Dental Association.

Bond Durability of a Repaired Resin Composite Using a Universal Adhesive and Different Surface Treatments.

To evaluate the long-term effect of different surface treatments on the repair microtensile bond strength (µTBS) of resin composite using a universal adhesive. Thirty-six resin composite blocks were fabricated and aged in 37°C distilled water for 1 month. The blocks were randomly assigned to different surface treatments: no treatment (control); diamond bur grinding (D); diamond bur + phosphoric acid cleaning (DP); diamond bur + silane application (DSi); diamond bur + phosphoric acid + silane (DPSi); and grit blasting with 50 µm H3PO4 particles + phosphoric acid + silane (APSi). Thereafter, Single Bond Universal adhesive was applied and repaired with the same composite. Composite-composite stick-shaped specimens were fabricated and subjected to the µTBS test either after 37°C water storage for 24 h or thermocycling for 10,000 cycles. Roughness of different surface-prepared specimens was measured by profilometer. Data were analysed using ANOVA and Duncan's post-hoc test (α = 0.05). Failure mode and micromorphology of different surface-prepared specimens were observed with SEM and EDS analysis. The highest µTBS was found in DPSi group at 24 h, and was significantly higher than others. The bond strengths in all thermocycled groups were significantly lower than those measured at 24 h. The highest µTBS was also found in the DPSi group, but this did not significantly differ from the DSi group. Thermocycling significantly reduced the repair bond strength. Diamond bur roughening with application of silane and universal adhesive yielded the highest repair bond strength for the aged resin composite.

Effect of dry abrasion treatments on composite surface quality and bonded joints shear strength

In order to enhance the adhesion properties of composites for further use in structural bonding applications, the effect of different surface treatments on flax/epoxy composite surface topography, surface arithmetic mean height (Sa), surface free energy ( γ s ) and composite to composite bonded joints shear strength (τ) was studied in this research. The main goal of this work was to evaluate the efficiency of abrasion surface treatments, such as sandblasting and sanding in enhancing composites’ adhesion quality compared to traditional mechanical surface treatments such as peel ply. Surface topography was evaluated using an optical microscope. Surface arithmetic mean height (Sa) was estimated via a mechanical surfscan. Surface free energy ( γ s ) was determined using the contact angle method along with the two-component Owens-Wendt model. Composite bonded joints shear strength was evaluated using the single lap shear joint test (SLJ). Trials revealed that specimens treated with sandblasting presented the highest composite bonded joints shear strength (τ). These specimens were characterized by a non-homogeneous surface topography, the highest surface arithmetic mean height (Sa) along with the highest surface free energy ( γ s ) and surface free energy dispersive component ( γ s d ).Unlike peel ply, sandblasting and sanding caused fiber exposure at the surface level. Sand granulometry used for sandblasting had an effect on the composite surface quality and its bonded joints shear strength. Linear regression revealed that composite bonded joints shear strength increases with the increase of the surface free energy dispersive component ( γ s d ). Abrasion treatments such as sandblasting significantly enhanced the adhesion properties of the composite compared to peel ply. Yet it did cause some side effects such as flax fiber damage and sand residue. These side effects could be reduced by opting for less harsh abrasive sand and more sophisticated cleaning processes.

Interfacial strengthening mechanism of SS/CFRTP/SS composite components prepared by mixed co-punch

Aiming at the preparation and forming of SS/CFRTP/SS composite components (CFRTP, thermoplastic carbon fiber composites; SS, stainless-steel), a mixed co-punching forming method of carbon fiber composites and stainless-steel is proposed. The effects of different surface treatments of stainless-steel on the shear strength, bending strength and crushing energy absorption of SS/CFRTP/SS composite components were also investigated, and the effects of ply angle on crushing energy absorption and bending strength of composites components were studied. The results show that the effect of SS/CFRTP/SS composite components prepared by mixed co-punching is very ideal. The bending strength of SS/CFRTP/SS composite component with 0 °/45 °/90 ° ply is the best, and the 0-direction ply has the best energy absorption effect. The addition of PA6 material between layers did not enhance the effect. The mechanical properties of SS/CFRTP/SS composite components with coupling agent after wire brush grinding are better than those obtained by only wire brush grinding. XPS analysis shows that the added silane coupling agent becomes a bridge to transfer stress load between the two materials through chemical reaction with the surfaces of the two materials. The micropores formed after surface treatment of stainless-steel form interlocking connection with CFRTP matrix. The excellent composite effect of SS/CFRTP/SS composite components is the result of physical and chemical interaction.