Atomistic Investigation on Mechanical Properties of Sn-Ag-Cu Based Nanocrystalline Solder Material

2019 ◽  
Author(s):  
Mohammad Motalab ◽  
Rafsan A. S. I. Subad ◽  
Ayesha Ahmed ◽  
Pritom Bose ◽  
Ratul Paul ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Md Simulations ◽  
Uniaxial Tensile ◽  
Solder Material ◽  
Embedded Atom ◽  
Sac Solder

Abstract In order to develop light weight electrical components, the nano-sized lead free solders have been identified as potential materials to provide better mechanical properties as compared to the conventional solders. Sn–Ag–Cu (SAC) solders have been widely acknowledged as one of the most promising replacements for Sn-Pb solders. In our previous work, mechanical properties of single crystal SAC solder material were investigated through atomistic simulation studies. In this work, the mechanical properties of nanocrystalline SAC305 (nc-SAC305) (96.5Sn-3.0Ag-0.5Cu) solder have been investigated through molecular dynamics (MD) simulations. A set of modified embedded atom method (MEAM) potential parameters have been proposed for nc-SAC solder. Impact of grain size, strain rate and temperature on the uniaxial tensile properties have been studied. The results have revealed an inverse Hall-Petch relationship in the nc-SAC305 material, and grain boundary decohesion is observed as the dominating failure mechanism. The results also suggest that the ultimate tensile strength of SAC305 significantly increases with increasing strain rate. Moreover, increased ductility and decreased ultimate tensile strength are observed at elevated temperatures.

Effect of Orientation on Mechanical Behavior of an Extruded Al Alloy

2008 ◽  
Author(s):  
M. A. Malik ◽  
I. Salam ◽  
W. Muhammad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Transverse Orientation ◽  
Longitudinal Orientation

The extruded materials are extensively used in chemical, food and nuclear industry and generally offer a unique combination of strength and freedom with regard to design solutions. During extrusion, material flow occurs in the direction of applied force and as a result microstructure change. The process ultimately induces variation in the mechanical properties when tested along or across the extrusion direction. The uniaxial tensile test is a simple and versatile test to expose most of the mechanical properties of the materials required to ensure the reliability of the systems. In present study, the mechanical behavior of an Al-Mg-Si alloy extruded cylinder has been determined with the help of uniaxial tensile test in longitudinal and transverse orientations. The microstructural features revealed significant difference in two orientations and constituent particles were found aligned in the direction of extrusion. Tensile tests were conducted in displacement mode at different cross head speeds corresponding to strain rates ranging from 10−5 to 10−1 s−1. The tests were conducted at ambient temperature in air atmosphere. The data thus obtained include: yield strength, ultimate tensile strength, percent elongation and reduction of area. Comparing the trends of strength variation, the material shows higher yield strength in longitudinal orientation as compared to transverse orientation. A slight increase in the yield strength with increasing strain rate was found in both the orientations. The ultimate tensile strength in both the directions was found similar and there was no appreciable change with increasing strain rate. The elongation and reduction in area were found higher in the longitudinal orientation. The effect of strain rate on these properties was negligible up to maximum speed tested. In longitudinal orientation typical dimpled fracture was observed indicating deformation before failure. In transverse orientation shallow dimples were present. The present study revealed that the distribution of constituent particles in an extruded thick-walled cylinder has a pronounced effect on its mechanical behavior and fracture morphology.

scholarly journals The Influence of Microstructure on the Mechanical Properties and Fracture Behavior of Medium Mn Steels at Different Strain Rates

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4228 ◽  
Author(s):  
Zheng Wang ◽  
Juanping Xu ◽  
Yu Yan ◽  
Jinxu Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Car Crash ◽  
Δ Ferrite

The primary task of automotive industry materials is to guarantee passengers’ safety during a car crash. To simulate a car crash, the influence of strain rates on mechanical properties and fracture behavior of medium Mn steels with different Si content (0Si without δ-ferrite and 0.6Si with about 20% δ-ferrite) was conducted using the uniaxial tensile test. The results show that ultimate tensile strength is higher, whereas total elongation is lower in 0Si than in 0.6Si. As the strain rate increases, ultimate tensile strength and total elongation decrease in both 0Si and 0.6Si; nonetheless, total elongation of 0.6Si decreases faster. Meanwhile, the area reduction of 0.6Si increases as the strain rate increases. The microcrack′s number on a rolling direction (RD)-transverse direction (TD) surface is considerably increased; nonetheless, the microcrack′s size is restrained in 0.6Si compared with 0Si. Microcracks start at γ(α′)/α-ferrite interfaces in both 0Si and 0.6Si, whereas little nucleation sites have also been found at (γ(α′)+α-ferrite)/δ-ferrite boundaries in 0.6Si. Meanwhile, δ-ferrite reveals a higher capacity for microcrack arrest. As the strain rate decreases, increased lower crack growth results in fine and even dimples on fractographs with abundant second cracks on fractographs; meanwhile, the small microcrack′s number increases, while the large microcrack′s number decreases on an RD-TD surface.

scholarly journals Effects of Gd, Y Content on the Microstructure and Mechanical Properties of Mg-Gd-Y-Nd-Zr Alloy

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 790 ◽  
Author(s):  
Changping Tang ◽  
Kai Wu ◽  
Wenhui Liu ◽  
Di Feng ◽  
Xuezhao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Solution Treatment ◽  
Age Hardening ◽  
Uniaxial Tensile ◽  
Microstructure And Mechanical Properties ◽  
Shaped Particle ◽  
Zr Alloy ◽  
Non Equilibrium

The effects of Gd, Y content on the microstructure and mechanical properties of Mg-Gd-Y-Nd-Zr alloy were investigated using hardness measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and uniaxial tensile testing. The results indicate that the alloys in as-cast condition mainly consist of α-Mg matrix and non-equilibrium eutectic Mg5.05RE (RE = Gd, Y, Nd). After solution treatment, the non-equilibrium eutectics dissolved into the matrix but some block shaped RE-rich particles were left at the grain boundaries and within grains. These particles are especially Y-rich and deteriorate the mechanical properties of the alloys. Both the compositions of the eutectic and the block shaped particle were independent of the total Gd, Y content of the alloys, but the number of the particles increases as the total Gd, Y content increases. The ultimate tensile strength increases as the total Gd, Y content decreases. A Mg-5.56Gd-3.38Y-1.11Nd-0.48Zr alloy with the highest ultimate tensile strength of 280 MPa and an elongation of 1.3% was fabricated. The high strength is attributed to the age hardening behavior and the decrease in block shaped particles.

Uncertainty quantification and prediction for mechanical properties of graphene aerogels via gaussian process metamodels

Nano Futures ◽  
2021 ◽  
Author(s):  
Bowen Zheng ◽  
Zeyu Zheng ◽  
Grace Gu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Gaussian Process ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamics Simulation ◽  
Uniaxial Tensile ◽  
Graphene Aerogel ◽  
Graphene Aerogels

Abstract Graphene aerogels, a special class of 3D graphene assemblies, are well known for their exceptional combination of high strength, lightweightness, and high porosity. However, due to microstructural randomness, the mechanical properties of graphene aerogels are also highly stochastic, an issue that has been observed but insufficiently addressed. In this work, we develop Gaussian process metamodels to not only predict important mechanical properties of graphene aerogels but also quantify their uncertainties. Using the molecular dynamics simulation technique, graphene aerogels are assembled from randomly distributed graphene flakes and spherical inclusions, and are subsequently subject to a quasi-static uniaxial tensile load to deduce mechanical properties. Results show that given the same density, mechanical properties such as the Young’s modulus and the ultimate tensile strength can vary substantially. Treating density, Young’s modulus, and ultimate tensile strength as functions of the inclusion size, and using the simulated graphene aerogel results as training data, we build Gaussian process metamodels that can efficiently predict the properties of unseen graphene aerogels. In addition, statistically valid confidence intervals centered around the predictions are established. This metamodel approach is particularly beneficial when the data acquisition requires expensive experiments or computation, which is the case for graphene aerogel simulations. The present research quantifies the uncertain mechanical properties of graphene aerogels, which may shed light on the statistical analysis of novel nanomaterials of a broad variety.

Nodular Silicon Al–(12–30)% Si Alloys: Microstructure, Mechanical Properties and Fracture Behaviors

2019 ◽  
Author(s):  
Ruyao Wang ◽  
Wei Hua Lu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Elevated Temperatures ◽  
Primary Silicon ◽  
Silicon Phase ◽  
Applied Loading ◽  
Initiation And Propagation ◽  
Si Content ◽  
Silicon Particles

The microstructure, mechanical properties, and fracture of nodular silicon hypereutectic Al–Si alloys containing 12–30 wt% Si are discussed. The eutectic and primary silicon particles are nodulized, offering an average aspect ratio of 1.60–1.70 with a designed modification practice followed by a solution heat treatment of 8–10 h at 510°C–520°C. Such a soaking temperature does not result in coarsening or clustering of the silicon particles. Nodulization of silicon phase leads to an increase in the tensile strength and ductility of alloys at room and elevated temperatures compared with commercial Al–Si alloys. Increasing the Si content leads the tensile strength and elongation of alloys at room temperature to fall down due to the formation of coarsen primary Si grains, but the ultimate tensile strength at 300°C remains unchanged. The ultimate tensile strength σb-alloy of hypereutectic Al–Si alloys is inversely proportional to square root of maximum silicon size dmax. The initiation and propagation of the crack with continuous increase in applied loading were observed under scanning electron microscope. The fracture surfaces in nodular silicon Al–Si alloys are composed of equiaxed ductile dimples. The finite-element method has been used to study the stress distribution within the different morphologies of Si grain and how Si and Al phases interact during loading.

scholarly journals High Strain Rate Tensile Properties of Annealed 2 1/4 Cr-1 Mo Steel

1976 ◽  
Vol 98 (4) ◽  
pp. 361-368 ◽  
Author(s):  
R. L. Klueh ◽  
R. E. Oakes
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
High Strain Rate ◽  
Strain Rate ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
High Strain ◽  
Total Elongation ◽  
Major Effect ◽  
Dynamic Strain

The high strain rate tensile properties of annealed 2 1/4 Cr-1 Mo steel were determined and the tensile behavior from 25 to 566°C and strain rates of 2.67 × 10−6 to 144/s were described. Above 0.1/s at 25°C, both the yield stress and the ultimate tensile strength increased rapidly with increasing strain rate. As the temperature was increased, a dynamic strain aging peak appeared in the ultimate tensile strength-temperature curves. The peak height was a maximum at about 350°C and 2.67 × 10−6/s. With increasing strain rate, a peak of decreased height occurred at progressively higher temperatures. The major effect of strain rate on ductility occurred at elevated temperatures, where a decrease in strain rate caused an increase in total elongation and reduction in area.

Thermal and Loading Effects on Mechanical Properties of a Hot Isostatically Pressed Si3N4

1994 ◽  
Author(s):  
Jagannathan Sankar ◽  
Jayant Neogi ◽  
Suneeta S. Neogi ◽  
Marvln T. Dixie ◽  
Ranji Vaidyanathan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silicon Nitride ◽  
Elevated Temperatures ◽  
Heat Engine ◽  
Tensile Tests ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Creep Tests ◽  
Loading Effects

The effect of thermal soaking on the mechanical properties of a candidate material for advanced heat engine applications namely, hot isostatically pressed (HIPed) silicon nitride (GTEPY6) are reported here. Pure uniaxial tensile tests conducted at room and at elevated temperatures indicated that the tensile strength of this material dropped significantly after 1000°C. The residual tensile strength of PY6 material after thermal soaking at 1200° and 1300°C was also investigated. Test results showed that thermal soaking at 1200° and 1300°C increased the residual tensile strength. The thermal soaking time had a greater effect on the residual tensile strength at 1300°C. Tensile creep tests performed at 1200° and 1300°C showed that the steady state creep rate was influenced by both the temperature and the applied stress. The higher stress exponent in HIPed as compared to a sintered silicon nitride shows higher creep resistance in the case of HIPed materials.

High Strain Rate Low Temperature Properties for SAC-R After Exposure to Isothermal Aging

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Mrinmoy Saha ◽  
Jeff Suhling ◽  
Ken Blecker
Keyword(s):  
Mechanical Properties ◽  
High Strain Rate ◽  
Strain Rate ◽  
Storage Temperature ◽  
High Strain ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Aging Effects ◽  
Space Applications ◽  
Sac Solder

Abstract Electronic parts in military, automotive, avionics and space applications may be subjected to sustained operation at high temperature in addition to high strain-rate loads. Parts may be stored in non-climate-controlled enclosures prior to deployment. Earlier studies on undoped SAC alloys have shown that the material properties evolve after prolonged period of storage at even modest temperatures. In order to mitigate the aging effects, a number of alloy formulation have been proposed. Data of the mechanical properties of lead-free solder alloys which is used for interconnection in the electronic packaging at high strain rates and at high storage temperature is very essential for design optimization of electronic package sustainability at extreme temperature environment because the SAC solders have shown to have degradation in mechanical properties at prolonged exposure to storage temperature. Industries have come up with a solution to reduce the degradation using dopants in SAC solder. In this study, a doped SAC solder called SAC-R has been subjected to high strain rate testing after extended storage at temperature of 50°C for 1 month, 2 months and 3 months. Samples with no aging and aged samples for up to 3-months have been subjected to uniaxial tensile tests to measure the mechanical properties of SAC-R for High and Low operating temperature ranging from −65°C to +200°C. The material data has been used to compute the constants for the Anand Visco-Plasticity model. The ability of the model to represent the material constitutive behavior has been quantified by comparing the model predictions of the uniaxial tensile test with the experimental data.

Mechanical Properties of a β Containing Ti-Al-Cr-Alloy at Ambient and Elevated Temperatures

1994 ◽  
Vol 364 ◽  
Author(s):  
W. R. Chen ◽  
J. Wang ◽  
B. Zhang ◽  
X. Wan ◽  
W. J. Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ambient Temperature ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
High Tensile Strength ◽  
Tial Alloys ◽  
Β Phase ◽  
Very High

AbstractThe mechanical properties of a β-containing Ti-Al-Cr alloy were investigated at ambient and elevated temperatures. The results show that the Ti-Al-Cr alloy containing the β phase has a very high tensile strength but a poor ductility at ambient temperature, and that higher ductility is obtained at high temperatures. The temperature dependence of mechanical properties is found to be sensitive to the strain rate during the test. Fractography shows that the fracture mode changes from fully brittle to ductile-brittle mixture with the increased temperature. All the results suggest that the triple-phased TiAl alloys (α2+β+γ) may have the combined mechanical properties of the dual-phased T13Al ((α2+β) and dual-phased TiAl (α2+γ) alloys.

scholarly journals The Crack Angle of 60° Is the Most Vulnerable Crack Front in Graphene According to MD Simulations

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1355
Author(s):  
Ishaq I. Alahmed ◽  
Sameh M. Altanany ◽  
Ismail Abdulazeez ◽  
Hassan Shoaib ◽  
Abduljabar Q. Alsayoud ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Strain Rate ◽  
Crack Front ◽  
Single Layer ◽  
Md Simulations ◽  
Crack Size ◽  
Single Layer Graphene ◽  
Crack Angle

Graphene is a type of 2D material with unique properties and promising applications. Fracture toughness and the tensile strength of a material with cracks are the most important parameters, as micro-cracks are inevitable in the real world. In this paper, we investigated the mechanical properties of triangular-cracked single-layer graphene via molecular dynamics (MD) simulations. The effect of the crack angle, size, temperature, and strain rate on the Young’s modulus, tensile strength, fracture toughness, and fracture strain were examined. We demonstrated that the most vulnerable triangle crack front angle is about 60°. A monitored increase in the crack angle under constant simulation conditions resulted in an enhancement of the mechanical properties. Minor effects on the mechanical properties were obtained under a constant crack shape, constant crack size, and various system sizes. Moreover, the linear elastic characteristics, including fracture toughness, were found to be remarkably influenced by the strain rate variations.

Sign in / Sign up

Export Citation Format

Share Document