scholarly journals IMCs Microstructure Evolution Dependence of Mechanical Properties for Ni/Sn/Ni Micro Solder-Joints

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 252 ◽  
Author(s):  
Ning Ren ◽  
Heng Fang ◽  
Dong Wang ◽  
Chenyi Hou ◽  
Yatao Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Brittle Fracture ◽  
Ductile Fracture ◽  
Solder Joints ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Scale Down ◽  
Long Rod

The current miniaturization trend of microelectronic devices drives the size of solder joints to continually scale down. The miniaturized joints considerably increase intermetallic compounds (IMCs) volume fraction to trigger mechanical reliability issues. This study investigated precise relationships between varying IMC volumes and mechanical properties of Ni/Sn(20μm)/Ni micro-joints. A designed method that followed the IMC volume as the only variable was used to prepare micro-joint samples with different IMC volumes. The continuously thickened Ni3Sn4 IMCs exhibited a noticeable morphology evolution from rod-like to chunky shape. The subsequent tensile tests showed unexpected tensile strength responses as increasing Ni3Sn4 volume, which was strongly associated with the Ni3Sn4 morphological evolutions. Fractographic analysis displayed that the ductile fracture dominates the 20%–40% IMC micro-joints, whereas the brittle fracture governs the 40%–80% IMC micro-joints. For the ductile fracture-dominated joints, an abnormal reduction in strength occurred as increasing IMCs volume from 20% to 40%. This is primarily due to severe stress concentrations caused by the transformed long rod-typed morphology of the Ni3Sn4. For the brittle fracture-dominated joints, the strength appeared a monotonous increase as the Ni3Sn4 volume increased. This may be attributed to the increased crack resistance resulting from continuous coarsening of the chunky Ni3Sn4 without any voids. Moreover, the finite element analysis was provided to further understand the joint failure mechanisms.

Mechanical Properties of SiCp/Cu Composites Prepared by Electric Conduction Sintering

2007 ◽  
Vol 353-358 ◽  
pp. 1402-1405 ◽  
Author(s):  
Chun Hua Wang ◽  
Shao Kang Guan ◽  
Shou Shan Li ◽  
Rui Zhang
Keyword(s):  
Mechanical Properties ◽  
Brittle Fracture ◽  
Flexural Strength ◽  
Ductile Fracture ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Electric Conduction

SiCp/Cu composites were fabricated at 700 oC and under 40MPa for 10min in vacuum by electric conduction sintering. The mechanical properties and microstructure of the composites were studied. The porosity of the composites increases when the volume fraction of SiCp exceeds 35%. The flexural strength of the composites decreases with increasing fraction of SiCp. The composites with 10 vol.% SiCp exhibited ductile fracture behavior, while composites with the volume fraction of SiCp in the range of 20–65% exhibited brittle fracture behavior. The composites with 35 vol.% SiCp showed the highest hardness.

scholarly journals Experimental Research and Simulation on the Mechanical Performance Degradation of Corroded Stud Shear Connectors

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Bing Wang ◽  
Xiaoling Liu ◽  
Jiantao Du
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Corrosion Rate ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Tensile Behavior ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Gtn Model

Electrochemical accelerated corrosion and tensile tests were conducted on six series of 30 stud specimens in this study to assess the various mechanical properties in corroded stud connectors. The results indicate that there is a gradual decline in mechanical properties (e.g., yield strength, ultimate strength, and plasticity) as stud corrosion rate increases. Degradation equations for these parameters were established via fitting analysis on the test data. A Gurson–Tvergaard–Needleman (GTN) constitutive model describing the tensile behavior of corroded studs was established based on mesodamage mechanics and finite element analysis. In the GTN model, the corrosion rate equals the original void volume fraction; the trial-and-error method was adopted to determine the relationship between the corrosion rate and material failure parameters. The finite element simulation results are in good agreement with the experimental results. The GTN model accurately simulates the uniaxial tensile behavior of the corroded stud.

Cellulose Whiskers Micro-Fibers Effect in the Mechanical Proprieties of PP and PLA Composites Fibers Obtained by Spinning Process

2011 ◽  
Vol 146 ◽  
pp. 12-26 ◽  
Author(s):  
A. Gherissi ◽  
R.Ben Cheikh ◽  
E. Dévaux ◽  
Fethi Abbassi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Failure Resistance ◽  
Cellulose Whiskers ◽  
Limit Strength

In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.

The Precise Determination of the Johnson–Cook Material and Damage Model Parameters and Mechanical Properties of an Aluminum 7068-T651 Alloy

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
B. Bal ◽  
K. K. Karaveli ◽  
B. Cetin ◽  
B. Gumus
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Physical Simulation ◽  
Damage Model ◽  
Rolling Direction ◽  
Stress Triaxiality ◽  
Material Model ◽  
Tensile Tests ◽  
Model Parameters ◽  
Element Analysis

Al 7068-T651 alloy is one of the recently developed materials used mostly in the defense industry due to its high strength, toughness, and low weight compared to steels. The aim of this study is to identify the Johnson–Cook (J–C) material model parameters, the accurate Johnson–Cook (J–C) damage parameters, D1, D2, and D3 of the Al 7068-T651 alloy for finite element analysis-based simulation techniques, together with other damage parameters, D4 and D5. In order to determine D1, D2, and D3, tensile tests were conducted on notched and smooth specimens at medium strain rate, 100 s−1, and tests were repeated seven times to ensure the consistency of the results both in the rolling direction and perpendicular to the rolling direction. To determine D4 and D5 further, tensile tests were conducted on specimens at high strain rate (102 s−1) and temperature (300 °C) by means of the Gleeble thermal–mechanical physical simulation system. The final areas of fractured specimens were calculated through optical microscopy. The effects of stress triaxiality factor, rolling direction, strain rate, and temperature on the mechanical properties of the Al 7068-T651 alloy were also investigated. Damage parameters were calculated via the Levenberg–Marquardt optimization method. From all the aforementioned experimental work, J–C material model parameters were determined. In this article, J–C damage model constants, based on maximum and minimum equivalent strain values, were also reported which can be utilized for the simulation of different applications.

scholarly journals Comparative finite-element analysis: a single computational modelling method can estimate the mechanical properties of porcine and human vertebrae

2014 ◽  
Vol 11 (95) ◽  
pp. 20140186 ◽  
Author(s):  
K. Robson Brown ◽  
S. Tarsuslugil ◽  
V. N. Wijayathunga ◽  
R. K. Wilcox
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Model Development ◽  
Computational Modelling ◽  
Bone Volume Fraction ◽  
Element Analysis ◽  
Modelling Method ◽  
Modelling Techniques ◽  
Musculoskeletal Systems ◽  
Development And Validation

Significant advances in the functional analysis of musculoskeletal systems require the development of modelling techniques with improved focus, accuracy and validity. This need is particularly visible in the fields, such as palaeontology, where unobservable parameters may lie at the heart of the most interesting research questions, and where models and simulations may provide some of the most innovative solutions. Here, we report on the development of a computational modelling method to generate estimates of the mechanical properties of vertebral bone across two living species, using elderly human and juvenile porcine specimens as cases with very different levels of bone volume fraction and mineralization. This study is presented in two parts; part I presents the computational model development and validation, and part II the virtual loading regime and results. This work paves the way for the future estimation of mechanical properties in fossil mammalian bone.

Multifunctional and specific interactions of CNTs in NBR and HNBR

2014 ◽  
Vol 11 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Chougule Harishkumar ◽  
Ulrich Giese ◽  
Robert Schuster
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Effective Interaction ◽  
Tensile Tests ◽  
Filler Loading ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
Multiwalled Carbon ◽  
Nitrile Butadiene Rubber ◽  
Polymer Filler

There are different techniques in practice to disperse multiwalled carbon nanotubes (MWCNTs) in elastomers. In the present work, commercially available MWCNTs NANOCYL NC 7000™ are used as filler. A synthetic Nitrile Butadiene Rubber (NBR) and Hydrogenated Nitrile Butadiene Rubber (HNBR) were used as polymer matrix for the composites prepared by melt blending. The filler dispersion in HNBR was studied through Transmission Electron Microscopy (TEM). The mechanical properties are investigated through strain sweep and tensile tests. Dielectric measurements are carried out to study electrical conductivity of the nanocomposites. Dynamic mechanical measurements showed an enhanced Payne effect and improvement in stiffness with increase in CNTs content into rubber matrix An improvement in electrical and mechanical properties in both NBR and HNBR system resulted by an increase in filler loading. The mechanical and electric percolation threshold of CNTs was found at very low filler volume fraction. Equilibrium swelling experiments were used to study polymer-filler interaction with the help of Kraus plot and diffusion coefficient. NBR showed higher polymer-filler interaction compared to HNBR. In NBR nanocomposites, CNTs showed higher interaction than carbon black. Good dispersion and effective interaction of the CNTs with the polymer led to significant mechanical reinforcing effects.

scholarly journals BENDING PROPERTIES OF A FUNCTIONALLY GRADED POLYMERIC COMPOSITE REINFORCED WITH A HYBRID NANOMATERIAL

2021 ◽  
Vol 21 (4) ◽  
pp. 302-319
Author(s):  
Mahdi M. S. Shareef ◽  
Ahmed Naif Al-Khazraji ◽  
Samir Ali Amin
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Functionally Graded ◽  
Hybrid Nanocomposites ◽  
Bending Test ◽  
Fe Model ◽  
Al2o3 Nanoparticles ◽  
Isotropic Layer ◽  
Element Analysis ◽  
Three Point Bending

In this paper, functionally graded polymer hybrid nanocomposites have been produced by silica (SiO2) nanoparticles and alumina (Al2O3) nanoparticles distributed in a matrix of epoxy during the ultra-sonication via hand lay-up method. The variation in nanoparticles volume fraction (Vf.) has been given in the thickness direction for reaching the gradation. Each layer has a thickness of 1.2 mm through various concentrations of nanoparticles and is sequentially cast in acrylic moulds to fabricate the graded composite sheet with a 6 mm thickness. To fabricate the functionally graded layers, various concentrations of different nanoparticles (1.5% SiO2, 1% SiO2, epoxy, 2% Al2O3 and 3% Al2O3) have been used for tensile and compressive testing each isotropic layer of functionally graded material (FGM). The mechanical property that was studied for pure epoxy, isotropic and FGM was the flexural resistance. The flexural properties of FGM, isotropic nanocomposite (1% SiO2 + 2% Al2O3) and pristine epoxy, for evaluating their mechanical properties, including flexural stress-strain criteria and flexural Young's modulus, were determined via a Three-point bending test, with loading from the side of silica and alumina for the hybrid-FGM and at one side for the isotropic hybrid nanocomposite and pristine epoxy. The mechanical properties (tensile and compression) and the density of every layer were obtained for the epoxy resin and nanocomposites. They can benefit from the Finite Element Analysis (FEA) of the Three-point bending test via the Design Modeler (ANSYS workbench). The results of experiments were confirmed via building a detailed 3D FE model. Also, the advanced deformation results from the FE model were found in good agreement with the experimental outcomes.

Fracture Analysis and Mechanical Properties of Magnesium Based Composites

2017 ◽  
Vol 891 ◽  
pp. 526-532 ◽  
Author(s):  
Beáta Ballóková ◽  
Dagmar Jakubéczyová
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Fracture Analysis ◽  
Physical Parameters ◽  
Weight Percentage ◽  
Matrix Microstructure ◽  
Angular Pressing ◽  
The Matrix ◽  
Average Size

Mechanical properties and microstructure and fracture analysis of a magnesium alloys based composite series with different volume fraction of alumina dispersoid nanoparticles were studied. The initial states of the composites were further treated by severe plastic deformation (SPD) using equal channel angular pressing (ECAP) in order to achieve microstructures with very fine grains of matrix. Microstructure parameters, in particular the matrix grain size, average size of the dispersed particles and their distribution, were observed using optical microscopy. The average grain sizes of MMCs decreased evidently with the increase of the weight percentage of Al2O3 particles additions and ECAP passes. The heat deformation process of such materials, besides the formation of incorporated Al2O3 particles, also leads to the creation of intermetallic compound Mg17Al12. Fracture surfaces after tensile tests at room and elevated temperature were studied by SEM. The fracture of studying materials were characterized as the ductile fracture due to the existence of a large number of dimples.In summary, it has been shown that mechanical properties are affected by lattice, physical parameters of phases within the composite systems. They are also affected by microstructure and substructure, which depend on the technology of compaction and densification.

scholarly journals Neutralization and Salt Effect on the Structure and Mechanical Properties of Polyacrylic Acid Gels under Equivolume Conditions

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 69
Author(s):  
Yui Tsuji ◽  
Mitsuhiro Shibayama ◽  
Xiang Li
Keyword(s):  
Mechanical Properties ◽  
Polyacrylic Acid ◽  
Salt Effect ◽  
Volume Fraction ◽  
Tensile Tests ◽  
The Other ◽  
Scattering Intensity ◽  
X Ray ◽  
Polyelectrolyte Gels ◽  
X Ray Scattering

The effects of neutralization and salt on the structure and mechanical properties of polyacrylic acid (PAA) gels under equivolume conditions were investigated by small-angle X-ray scattering (SAXS) measurements and tensile tests. We attained the equivolume condition by immersing a piece of PAA gel sample in an ion reservoir containing linear PAA, NaOH, and NaCl at prescribed concentrations (post-ion-tuning). The volume fraction of the linear polymer was set to be the same as that of the gel so as to satisfy the iso-osmotic pressure at the reference state. Various types of reservoirs were prepared by adding NaOH and/or NaCl with different concentrations to the reference reservoir, followed by immersing a PAA gel piece. In the SAXS measurements, a scattering peak appeared, and the scattering intensity at q = 0 decreased by neutralization, while the addition of salt increased the scattering intensity. On the other hand, Young’s modulus measured with the tensile test decreased with neutralization; however, it scarcely changed with the addition of salt. The newly developed equivolume post-ion-tuning technique may serve as a new standard scheme to study polyelectrolyte gels.

scholarly journals Influence of Infill Pattern on the Elastic Mechanical Properties of Fused Filament Fabrication (FFF) Parts through Experimental Tests and Numerical Analyses

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5459
Author(s):  
Jordi Bonada ◽  
Mª Magdalena Pastor ◽  
Irene Buj-Corral
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Numerical Analyses ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Element Analysis ◽  
Young’S Moduli ◽  
Printing Parameters

Fused Filament Fabrication (FFF) is one of the most extensive additive manufacturing technologies for printing prototypes or final parts in various fields. Some printed parts need to meet structural requirements to be functional parts. Therefore, it is necessary to know the mechanical behavior of the printed samples as a function of the printing parameters in order to optimize the material used during the manufacturing process. It is known that FFF parts can present orthotropic characteristics as a consequence of the manufacturing process, in which the material is deposited layer by layer. Therefore, these characteristics must be considered for a correct evaluation of the printed parts from a structural point of view. In this paper, the influence of the type of filling pattern on the main mechanical properties of the printed parts is analyzed. For this purpose, the first parts are 3D printed using three different infill patterns, namely grid, linear with a raster orientation of 0 and 90°, and linear with a raster orientation of 45°. Then, experimental tensile tests, on the one hand, and numerical analyses using finite elements, on the other hand, are carried out. The elastic constants of the material are obtained from the experimental tests. From the finite element analysis, using a simple approach to create a Representative Volume Model (RVE), the constitutive characteristics of the material are estimated: Young’s Moduli and Poisson’s ratios of the printed FFF parts. These values are successfully compared with those of the experimental tests. The results clearly show differences in the mechanical properties of the FFF printed parts, depending on the internal arrangement of the infill pattern, even if similar 3D printing parameters are used.

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