scholarly journals Effect of Pulse Current-Assisted Rolling on the Interface Bonding Strength and Microstructure of Cu/Al Laminated Composite

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1555
Author(s):  
Hao Song ◽  
Weixin Hao ◽  
Xiaowei Mu ◽  
Tingzhuang Han ◽  
Chaojie Che ◽  
...  
Keyword(s):  
Bonding Strength ◽  
Pulse Current ◽  
Intermetallic Phase ◽  
Laminated Composite ◽  
Copper Surface ◽  
Copper Sheet ◽  
Rolling Method ◽  
Small Cracks ◽  
Interface Bonding Strength ◽  
Shear Interface

In this paper, Cu/Al laminated composite was prepared by adopting the pulse current-assisted rolling method, and the microstructure and mechanical properties of the material were investigated. The results showed that the Cu/Al laminated composite with pulsed current was significantly strengthened. The composite interface of Cu/Al laminated composite with pulse current-assisted rolling was found without intermetallic phase, and its bonding mode was mainly mechanical combined. The number of reticulated ridges increased at the shear interface. The small cracks on the copper surface were firmly embedded in the aluminum metal. There were obvious folds on the copper surface without aluminum embedding. The structural change of the bonding interface increases the contact area between copper sheet and aluminum sheet, thereby enhancing the bonding strength of the Cu/Al laminated composite.

scholarly journals Improved Copper–Epoxy Adhesion by Laser Micro- and Nano-Structuring of Copper Surface for Thermal Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1721
Author(s):  
Mario Mora ◽  
Hippolyte Amaveda ◽  
Luis Porta-Velilla ◽  
Germán F. de la Fuente ◽  
Elena Martínez ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bonding Strength ◽  
Copper Surface ◽  
Heat Sinks ◽  
Electrical Insulation ◽  
Cryogenic Temperatures ◽  
Shear Tests ◽  
Patterned Structures ◽  
Different Temperatures ◽  
Mechanical Tensile

The objective of this work is the enhancement of metal-to-metal bonding to provide high thermal conductivity together with electrical insulation, to be used as heat sinks at room and cryogenic temperatures. High thermal conductive metal (copper) and epoxy resin (Stycast 2850FT) were used in this study, with the latter also providing the required electrical insulation. The copper surface was irradiated with laser to induce micro- and nano-patterned structures that result in an improvement of the adhesion between the epoxy and the copper. Thus, copper-to-copper bonding strength was characterized by means of mechanical tensile shear tests. The effect of the laser processing on the thermal conductivity properties of the Cu/epoxy/Cu joint at different temperatures, from 10 to 300 K, is also reported. Using adequate laser parameters, it is possible to obtain high bonding strength values limited by cohesive epoxy fracture, together with good thermal conductivity at ambient and cryogenic temperatures.

Thermal Shock Behavior and Bonding Strength of MoSi2-BaO-Al2O3-SiO2 Gradient Porous Coating with Polymethyl Methacrylate Addition for Porous Fibrous Insulations

2018 ◽  
Vol 281 ◽  
pp. 493-498
Author(s):  
Ya Yu Su ◽  
Xiao Lei Li ◽  
Hui Jie Tang ◽  
Zhi Hao Zhao ◽  
Jian He
Keyword(s):  
Porous Structure ◽  
Thermal Shock ◽  
Bonding Strength ◽  
Thermal Shock Resistance ◽  
Porous Coating ◽  
Bonding Layer ◽  
Interface Bonding ◽  
Shock Resistance ◽  
Thermal Shock Behavior ◽  
Interface Bonding Strength

In order to improve the thermal shock behavior of high temperature resistant coating on porous fibrous referactory insulations, the MoSi2-BaO-Al2O3-SiO2(MoSi2-BAS) gradient porous coatings were designed by preparing a dense surface layer and a porous bonding layer with the method of brushing and subsequent sintering at 1773 K. The porous bonding layer was obtained by adding polymethyl methacrylate (PMMA) as pore former. As the content of PMMA increases, the MoSi2-BAS coatings changed from a dense structure into a gradient porous structure. The interface bonding strength and thermal shock resistance of the MoSi2-BAS coatings were investigated. The result shows that the as-prepared coating with gradient porous structure exhibited excellent thermal shock resistance, which remained gradient structure without cracking after thermal cycling 100 times between 1773 K and room temperature. And the interface bonding strength of the gradient porous coating reached 1.5±0.08 Mpa, which was much better than that of the dense coating.

Experimental evaluation of the tensile bonding strength of the basalt fiber-reinforced polymer–concrete interface

2020 ◽  
Vol 23 (15) ◽  
pp. 3323-3334
Author(s):  
Buntheng Chhorn ◽  
WooYoung Jung
Keyword(s):  
High Temperature ◽  
Bonding Strength ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Polymer Concrete ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Interface Bonding Strength ◽  
Concrete Interface ◽  
Basalt Fiber Reinforced Polymer

The bonding performance of basalt fiber-reinforced polymer and concrete substrate has a significant effect on the reliability of externally strengthened existing concrete structure, due to being the most vulnerable element to failure in this fiber-reinforced polymer–concrete strengthening system. Its failure can result in the failure of the whole structure. Although many previous researchers have been interested in the tensile bonding strength of carbon fiber-reinforced polymer and glass fiber-reinforced polymer–concrete interface, that of basalt fiber-reinforced polymer–concrete interface has been very limited. Thus, the objective of this study is to experimentally assess the tensile bonding strength of the basalt fiber-reinforced polymer–concrete interface. The effects of high temperature, freezing–thawing cycles, type of resin, and concrete crack widths on the tensile bonding strength are also investigated. The pull-off experiment is conducted according to ASTM D7522/D7522M-15. A total of 205 core specimens of 50 mm diameter and 10 mm depth were taken from 41 concrete beams. The experimental results illustrate that both freezing–thawing and high-temperature condition have a substantial effect on the bonding strength of the basalt fiber-reinforced polymer–concrete interface. Bonding strength was decreased within the range of about 9%–30% when the number of freezing–thawing cycles increases from 100 to 300; likewise, it was decreased up to 30% when the exposure temperature rises to 200°C. Also, the specimens which were repaired to close their cracks by epoxy resin had no significant effect on the bonding strength of basalt fiber-reinforced polymer–concrete interface, when the specimens had crack width of less than 1.5 mm.

The Production and Properties of Electrolytic Zn-Ni Layers Deposited by Pulse Current Method

2010 ◽  
Vol 636-637 ◽  
pp. 1047-1052
Author(s):  
Katarzyna Wykpis ◽  
Antoni Budniok
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Pulse Current ◽  
Chemical Elements ◽  
Testing Machine ◽  
Intermetallic Phase ◽  
Current Method ◽  
Surface Chemical ◽  
Surface Chemical Composition ◽  
Current Densities

The Zn-Ni layers were obtained by electrolytic method in the conditions of pulse current with symmetric current pause. The austenitic steel (OH18N9) was used as the cathode. The morphology, phase and surface chemical composition of the layers deposited at reduction current densities ic = 5 – 25 mAcm2, were defined. The surface morphology of deposited layers and surface chemical elements distribution were studied using a scanning electron microscope (JEOL JSM-6480). On the basis on this research, the possibility of deposition of Zn-Ni layers contained about 8 – 10 % at. Ni was exhibited. The optimal pulse current condition of Zn-Ni layers deposition were proposed namely ic=20mA•cm2, ton = toff = 2ms. It was stated, that surface chemical composition of Zn-Ni layers is independent on pulse current densities of deposition, whereas development of Zn-Ni surface increases with the increase in the pulse current density of deposition. The corrosion resistance investigations showed that passivation and heat treatment improved the corrosion resistance of Zn-Ni layers in 5% NaCl solution. Higher corrosion resistance of heated Zn-Ni layers is caused by the creation of Ni5Zn21 intermetallic phase. Moreover the heated Zn-Ni layers are characterized by slightly higher corrosion resistance compared with metallic Cd. Microhardness of the layers was investigated by Vickers diamond testing machine.

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