Effect of water immersion on adhesion strength of a aluminum-alloy/epoxy-resin joint

Abstract Direct bonding of metal-resin plays a critical role in jointing of dissimilar materials and the adhesion strength is known to be dependent on strain rate (loading rate) due to the strain rate sensitivity of polymeric resin. This study evaluated adhesion strength and adhesion durability against repetitive loading for the interface between aluminum alloy and epoxy resin. For experiment, a pulsed YAG laser was used to generate strong elastic waves, resulting in interfacial fracture. This method is called Laser Shock Adhesion Test (LaSAT), which enables us to evaluate impact strength of interfacial fracture. This study prepared two types of specimens with different curing temperature (20°C and 100°C). It is found that the specimen with higher temperature curing shows larger adhesion strength. Subsequently, repetitive LaSAT experiments (cyclic loading tests) were conducted to evaluate adhesion durability. This reveals that adhesion strength showed cyclic fatigue characteristics and higher curing temperature improves fatigue strength. To elucidate this mechanism at molecular level, molecular dynamics (MD) simulation was conducted for the interfacial material with epoxy resin. This study created all-atomistic model of Al2O3/epoxy resin interface, and repetitive tensile deformation was applied until delamination. It is found that the number of loading cycles to delamination was increased when the applied tensile stress was lower. It is also found that the 400K curing model showed larger adhesion strength than that of the 300K curing model. This trend is very similar with the results of LaSAT experiments. Our comprehensive study with LaSAT experiments and MD simulations evaluates adhesion strength of Al/epoxy interface and reveals its fracture mechanism.

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Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers

Materials ◽

10.3390/ma14051261 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1261

Author(s):

Catarina S. P. Borges ◽

Alireza Akhavan-Safar ◽

Eduardo A. S. Marques ◽

Ricardo J. C. Carbas ◽

Christoph Ueffing ◽

...

Keyword(s):

Mechanical Properties ◽

Water Absorption ◽

Water Uptake ◽

Significant Influence ◽

Water Immersion ◽

Water Diffusion ◽

Polybutylene Terephthalate ◽

Chemical Changes ◽

Water Ingress ◽

Effect Of Water

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.

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Effect of water immersion on renin-aldosterone and renal sodium handling in normal man.

Journal of Applied Physiology ◽

10.1152/jappl.1971.31.3.368 ◽

1971 ◽

Vol 31 (3) ◽

pp. 368-374 ◽

Cited By ~ 49

Author(s):

M Epstein ◽

T Saruta

Keyword(s):

Water Immersion ◽

Effect Of Water ◽

Normal Man ◽

Renal Sodium Handling ◽

Sodium Handling

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Effect of water-immersion stress on prostaglandin E2 in rat gastric mucosa

Gastroenterologia Japonica ◽

10.1007/bf02815803 ◽

1981 ◽

Vol 16 (3) ◽

pp. 236-241 ◽

Cited By ~ 18

Author(s):

Tetsuo Arakawa ◽

Kenzo Kobayashi ◽

Hajime Nakamura ◽

Shinji Chono ◽

Hiroaki Yamada ◽

...

Keyword(s):

Gastric Mucosa ◽

Prostaglandin E2 ◽

Water Immersion ◽

Effect Of Water ◽

Rat Gastric Mucosa

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Effect of Water Absorption Behaviour on Tensile Properties of Hybrid Jute-Roselle Woven Fibre Reinforced Polyester Composites

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.18.4.2021.02.0705 ◽

2021 ◽

Vol 18 (4) ◽

Author(s):

Agung Efriyo Hadi ◽

Tezara Cionita ◽

Deni Fajar Fitriyana ◽

Januar Parlaungan Siregar ◽

Ahmed Nurye Oumer ◽

...

Keyword(s):

Tensile Strength ◽

Water Absorption ◽

Fibre Composite ◽

Unsaturated Polyester ◽

Water Immersion ◽

Tensile Modulus ◽

Natural Fibre ◽

Jute Fibre ◽

Thickness Swelling ◽

Effect Of Water

Incorporating natural fibre as reinforcement in the polymer matrix has shown a negative effect since the natural fibre is hydrophilic. The natural fibre easily absorbs water which causes an effect on the mechanical properties of the composites. The objective of this paper is to investigate the water absorption behaviour of hybrid jute-roselle woven fibre reinforced unsaturated polyester composite and the effect of water absorption in terms of tensile strength and tensile modulus. The effect of hybrid composite on the thickness swelling will be tested. The fabrication method used in this study is the hand lay-up technique to fabricate 2-layer and 3-layer composites with layering sequences of woven jute (J)/roselle (Ro) fibre. The results of the study showed that pure roselle fibres for 2 and 3-layer composites have the highest water absorption behaviour 3.86% and 5.51%, respectively, in 28 days) as well as thickness swelling effect, whereas hybrid J-Ro and J-J-Ro composites showed the least water absorption (2.65% and 3.76%, respectively) in 28 days) in both the tests. The hybridisation between jute and roselle fibres reduced water absorption behaviour and improved the fibres dimensional stability. The entire composites showed a decreasing trend for both tensile strength and tensile modulus strength after five weeks of water immersion. Jute fibre composite hybridised with roselle fibre can be used to reduce the total reduction of both tensile strength and tensile modulus throughout the whole immersion period. Moreover, the tensile testing showed that jute fibre composite hybridised with roselle fibre have produced the strongest composite with the highest tensile and modulus strength compared to other types of composites. The hybridisation of diverse fibre reinforcements aids in minimising the composite water absorption and thickness swelling, hence reducing the effect of tensile characteristics.

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Preparation of Ti–Zr-Based Conversion Coating on 5052 Aluminum Alloy, and Its Corrosion Resistance and Antifouling Performance

Coatings ◽

10.3390/coatings8110397 ◽

2018 ◽

Vol 8 (11) ◽

pp. 397 ◽

Cited By ~ 6

Author(s):

Hehong Zhang ◽

Xiaofeng Zhang ◽

Xuhui Zhao ◽

Yuming Tang ◽

Yu Zuo

Keyword(s):

Corrosion Resistance ◽

Surface Modification ◽

Aluminum Alloy ◽

Current Density ◽

Corrosion Current Density ◽

Salt Water ◽

Water Immersion ◽

Chemical Conversion ◽

Corrosion Current ◽

Conversion Coating

A chemical conversion coating on 5052 aluminum alloy was prepared by using K2ZrF6 and K2TiF6 as the main salts, KMnO4 as the oxidant and NaF as the accelerant. The surface morphology, structure and composition were analyzed by SEM, EDS, FT–IR and XPS. The corrosion resistance of the conversion coating was studied by salt water immersion and polarization curve analysis. The influence of fluorosilane (FAS-17) surface modification on its antifouling property was also discussed. The results showed that the prepared conversion coating mainly consisted of AlF3·3H2O, Al2O3, MnO2 and TiO2, and exhibited good corrosion resistance. Its corrosion potential in 3.5 wt % NaCl solution was positively shifted about 590 mV and the corrosion current density was dropped from 1.10 to 0.48 μA cm−2. By sealing treatment in NiF2 solution, its corrosion resistance was further improved yielding a corrosion current density drop of 0.04 μA cm−2. By fluorosilane (FAS-17) surface modification, the conversion coating became hydrophobic due to low-surface-energy groups such as CF2 and CF3, and the contact angle reached 136.8°. Moreover, by FAS-17 modification, the corrosion resistance was enhanced significantly and its corrosion rate decreased by about 25 times.

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