Estimation of Mechanical Properties of Al/Cu Compound Layer Formed by Impact Welding

2005 ◽  
Vol 502 ◽  
pp. 455-460 ◽  
Author(s):  
Hidefumi Date ◽  
Masatoshi Futakawa ◽  
Masaaki Naka

The impact welding of aluminum onto copper was carried out using a gas gun and the mechanical properties of Al/Cu joint were investigated by tensile tests and micro hardness indentation tests. The strength measured by tensile test decreased with increasing of the impact velocity. The results of the tensile test suggested that it was necessary to make a microscopic survey of the joint interface. Then, the inverse analysis with FEM analysis was applied to the load and depth curves measured by the indentation technique to identify the material constants in the constitutive equations of aluminum, copper and the compound layer. In addition, the numerical simulation for the tensile test was carried out using the identified material constants of aluminum, copper and the compound layer. The nominal stress-strain curve of the compound layer obtained by the numerical simulation showed the typical feature of brittle material. The ultimate tensile stress of the compound layer was about 1.2 GPa and ten times larger than that of aluminum. It was concluded that the bonding strength of Al/Cu joint was dependent on the integrity of the compound layer.

2021 ◽  
Vol 60 (1) ◽  
pp. 342-351
Author(s):  
Małgorzata Chwał ◽  
Aleksander Muc

Abstract Mechanical properties of carbon nanotube (CNT)-based nanocomposites are broadly discussed in the literature. The influence of CNT arrangements on the elastic properties of nanocomposites based on the finite-element method (FEM) and representative volume element (RVE) approach is presented here. This study is an application of RVE modeling in the characterization of elastic behavior of CNT polymer nanocomposites. Our main contribution is the analysis of the impact of a nanotube arrangement on the elastic properties of nanocomposite to comprehensively determine the material constants. While most of the articles are focused on one distribution, not all material constants are determined. Our FEM analysis is compared with micromechanical models and other results from the literature. The current work shows that nanotube arrangements lead to different results of elastic properties. The analytical micromechanical models are consistent with the numerical results only for axial Young’s modulus and Poisson’s ratio, whereas other elastic constants are lower than the numerical predictions. The results of these studies indicate that FEM can predict nanocomposite mechanical properties with good accuracy. This article is helpful and useful to comprehensively understand the influence of CNT arrangements on the elastic properties of nanocomposites.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1137
Author(s):  
Sascha Stanic ◽  
Thomas Koch ◽  
Klaus Schmid ◽  
Simone Knaus ◽  
Vasiliki-Maria Archodoulaki

Blends of two long-chain branched polypropylenes (LCB-PP) and five linear polypropylenes (L-PP) were prepared in a single screw extruder at 240 °C. The two LCB-PPs were self-created via reactive extrusion at 180 °C by using dimyristyl peroxydicarbonate (PODIC C126) and dilauroyl peroxide (LP) as peroxides. For blending two virgin and three recycled PPs like coffee caps, yoghurt cups and buckets with different melt flow rate (MFR) values were used. The influence of using blends was assessed by investigating the rheological (dynamic and extensional rheology) and mechanical properties (tensile test and impact tensile test). The dynamic rheology indicated that the molecular weight as well as the molecular weight distribution could be increased or broadened. Also the melt strength behavior could be improved by using the two peroxide modified LCB-PP blends on the basis of PODIC C126 or PEROXAN LP (dilauroyl peroxide). In addition, the mechanical properties were consistently enhanced or at least kept constant compared to the original material. In particular, the impact tensile strength but also the elongation at break could be increased considerably. This study showed that the blending of LCB-PP can increase the investigated properties and represents a promising option, especially when using recycled PP, which demonstrates a real “up-cycling” process.


2019 ◽  
Author(s):  
Marek Jałbrzykowski ◽  
Sławomir Obidziński ◽  
Wioletta Świder ◽  
Magdalena Dołżyńska

The paper presents the research results of the impact of reduced graphene oxide (RGO) on selected mechanical and functional properties of LDPE foil. The foils were made by blow extrusion, with different amounts of RGO added to the granulate prior the extrusion process. Prepared foil samples were assessed for mechanical properties in a static tensile test and the assessment of their bacterial resistance was tested. The impact of RGO on antibacterial interactions and favorable mechanical properties of the foils were found. Analysis of the results allowed to select the most advantageous solution which was prepared for industrial applications.


2012 ◽  
Vol 446-449 ◽  
pp. 2186-2191
Author(s):  
Jian Guo ◽  
Qi Cai Wang ◽  
Rong Ling Zhang ◽  
Zhi Guo Yang

According to the mechanical properties of the parallel-adjective tunnel, the construction process is simulated and the displacements and concrete stress of the lining structure is monitored of an actual tunnel in the loess region. The influence which the new tunnel on the existing tunnel lining during the new tunnel construction process studied by comparatively analyzed the numerical simulation and monitoring the results. The results show that the impact on the existing tunnel during the new tunnel excavation changes with tunnel distance and the excavation method of the new tunnel, when the line distance increases the impact on the existing tunnel has been remarkably reduced.


2014 ◽  
Vol 611-612 ◽  
pp. 521-528 ◽  
Author(s):  
Laurent Tabourot ◽  
Pascale Balland ◽  
Ndéye Awa Sene ◽  
Mathieu Vautrot ◽  
Nesrine Ksiksi ◽  
...  

This article deals with numerical simulation of necking. It draws the attention onto the importance of the description of strain-hardening and the effects on the evolution of necking. In order to compare necking evolution in relation with different plasticity models, a tracking procedure which consists in determining the evolution over time of discharged volumes of the sample is adopted. Models that take into account physical phenomena at the microscopic level and especially the heterogeneities of materials from a mechanical point of view seem well suited to fit experimental evidence connected to necking.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4224
Author(s):  
Che-Yu Lin ◽  
Jiunn-Horng Kang

Mechanical properties are crucial parameters for scaffold design for bone tissue engineering; therefore, it is important to understand the definitions of the mechanical properties of bones and relevant analysis methods, such that tissue engineers can use this information to properly design the mechanical properties of scaffolds for bone tissue engineering. The main purpose of this article is to provide a review and practical guide to understand and analyze the mechanical properties of compact bone that can be defined and extracted from the stress–strain curve measured using uniaxial tensile test until failure. The typical stress–strain curve of compact bone measured using uniaxial tensile test until failure is a bilinear, monotonically increasing curve. The associated mechanical properties can be obtained by analyzing this bilinear stress–strain curve. In this article, a computer programming code for analyzing the bilinear stress–strain curve of compact bone for quantifying the associated mechanical properties is provided, such that the readers can use this computer code to perform the analysis directly. In addition to being applied to compact bone, the information provided by this article can also be applied to quantify the mechanical properties of any material having a bilinear stress–strain curve, such as a whole bone, some metals and biomaterials. The information provided by this article can be applied by tissue engineers, such that they can have a reference to properly design the mechanical properties of scaffolds for bone tissue engineering. The information can also be applied by researchers in biomechanics and orthopedics to compare the mechanical properties of bones in different physiological or pathological conditions.


2021 ◽  
Vol 71 (03) ◽  
pp. 359-364
Author(s):  
Abir Roy ◽  
Abhishek Kumar

In the present study, AlMgSi alloy was processed through multi-axial compression (MAC) to produce ultrafine-grained microstructure at room temperature. The AlMgSi alloys are widely used in automobile industries for making cylinder heads and brake disks etc. MAC was performed up to three cycles and showed improvement in mechanical properties. The impact of different strain levels upon microstructure changes is investigated using electron backscatter diffraction (EBSD). The average grain size reduced from an initial average grain size of ~ 124 to ~ 3 μm after completion of three cycles of MAC processing. Samples were tested for mechanical properties using uniaxial tensile test, hardness measurements, and corrosion. Tensile test results show a considerable increase in yield strength from ~90 MPa to ~249 MPa after 3 cycles of MAC. The average hardness value increased from 52 VHN to 90 VHN after 3 cycles of MAC. The corrosion resistance of MAC processed samples was found to decrease in comparison to solution-treated samples.


2007 ◽  
Vol 127 ◽  
pp. 283-288 ◽  
Author(s):  
Hidefumi Date ◽  
Masaaki Naka

When a cylindrical projectile is impact-welded to a flat target, a compound layer is usually observed at the joining interface as a result of the impact welding. In this study, the formation process of the compound layer was formulated as a moving boundary problem, which is a phase transformation technique. The numerical results were compared with the experiment results obtained using an aluminum projectile and stainless steel target. Numerical analysis shows that the melting area is similar to the temperature profile given at the boundary face. The area of the compound layer formed at the joining interface almost agrees with the melting area of the target. The profile of the compound layer is similar to the triangular temperature profile in the given temperature profiles. The mixing ratio of the melting weights of aluminum and stainless steel obtained by the numerical analysis strongly depends on the temperature rise at the interface. The melted weight of aluminum in the experiment is somewhat greater than that in the numerical analysis. The heat conduction analysis including deformation of the projectile and target make the results of the numerical analysis closer to the experimental results.


2014 ◽  
Vol 794-796 ◽  
pp. 357-364
Author(s):  
Shinji Kumai

Solid-state welding is useful to join dissimilar metal couples, in particular, with a large difference in physical and mechanical properties. However, conventional solid-state welding methods such as diffusion welding and roll bonding are not necessarily applicable to all metal combinations. In addition, they are time-consuming. In the present study, various dissimilar metal joints (e.g. Al/Fe, Al/Cu, Al/Ni, A2024/A5052, A6022/steel, A6022/Plated steel, A2024/AZ80) were fabricated by using several types of high-speed solid-state welding methods; friction stir spot welding, advanced stud welding and impact welding. The strength and characteristic interfacial morphology of the joints were investigated, and each joining mechanism is discussed. In particular, for the impact welding, both experimental and numerical analyses were performed. Two metal sheets were obliquely collided at a very high speed and joined by magnetic pressure or explosive force. Smoothed Particle Hydrodynamics (SPH) method was used to simulate the impact welding process. The emission of metal jet and the evolution of characteristic wavy interface at the joint interface could be clearly visualized. The effects of collision angle, collision velocity and difference in density of the metals on the wave morphology were revealed.


2010 ◽  
Vol 638-642 ◽  
pp. 2166-2171 ◽  
Author(s):  
Hisashi Serizawa ◽  
Isao Shibaharar ◽  
Sherif Rashed ◽  
Hidekazu Murakawa

The magnetic pressure seam welding is one of the candidate methods to join thin sheet smart and multifunctional materials. In this research, to examine the mechanism of magnetic pressure welding from a dynamic viewpoint, numerical simulation of the impact was carried out by using a commercial Euler-Lagrange coupling software MSC.Dytran (MSC.Software) as a first step of the computational studies, where the joint between Fe and Al was employed according to the previous experimental researches. From the serial numerical results, it was found that the increase of temperature at the joint interface was not enough to melt Al or Fe in the range of collision velocity and angle studied in this report. Also, it was revealed that the very large mean stress occurred at the interface which could be considered as the pressure at joint interface and Al moved with high velocity along the interface. Moreover, it was found that there were two patterns of plastic strain distribution near the joint interface depending on the collision velocity and collision angle. Finally, it can be concluded that the plastic strain pattern might be related to the success of magnetic pressure seam welding.


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