Mechanical Properties of 35CrMoA Steel at High Strain Rate Loading

The tensile properties of alloy steel 35CrMoA were measured by dynamic tension experimental apparatus, and the stress-strain curves of the material at strain rate range from 10-2/s to 103/s were obtained. The fracture appearance and metallurgical structure were observed for the recovered specimens. The influence of strain rates on mechanical properties and microstructure of the 35CrMoA steel was analyzed. Based on the experimental data of mechanical properties, the JC constitutive parameters were fitted for 35CrMoA.

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Strain ageing effect on the temperature dependent mechanical properties of partially damaged structural mild-steel induced by high strain rate loading

Construction and Building Materials ◽

10.1016/j.conbuildmat.2016.07.001 ◽

2016 ◽

Vol 123 ◽

pp. 454-463 ◽

Cited By ~ 11

Author(s):

Sajjad Hosseini ◽

Amin Heidarpour ◽

Frank Collins ◽

Christopher R. Hutchinson

Keyword(s):

Mechanical Properties ◽

Mild Steel ◽

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

Ageing Effect ◽

Temperature Dependent ◽

Strain Ageing ◽

Strain Rate Loading

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High Strain Rate Superplasticity in Al-Zn-Mg-Based Alloy: Microstructural Design, Deformation Behavior, and Modeling

Materials ◽

10.3390/ma13092098 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2098 ◽

Cited By ~ 1

Author(s):

Olga Yakovtseva ◽

Maria Sitkina ◽

Ahmed O. Mosleh ◽

Anastasia Mikhaylovskaya

Keyword(s):

High Strain Rate ◽

Strain Rate ◽

Superplastic Deformation ◽

High Strain ◽

Flow Behavior ◽

Constant Strain Rate ◽

Superplastic Forming ◽

High Strength ◽

Strain Rate Range ◽

Strain Rates

Increasing the strain rate at superplastic forming is a challenging technical and economic task of aluminum forming manufacturing. New aluminum sheets exhibiting high strain rate superplasticity at strain rates above 0.01 s−1 are required. This study describes the microstructure and the superplasticity properties of a new high-strength Al-Zn-Mg-based alloy processed by a simple thermomechanical treatment including hot and cold rolling. The new alloy contains Ni to form Al3Ni coarse particles and minor additions of Zr (0.19 wt.%) and Sc (0.06 wt.%) to form nanoprecipitates of the L12-Al3 (Sc,Zr) phase. The design of chemical and phase compositions of the alloy provides superplasticity with an elongation of 600–800% in a strain rate range of 0.01 to 0.6/s and residual cavitation less than 2%. A mean elongation-to-failure of 400% is observed at an extremely high constant strain rate of 1 s−1. The strain-induced evolution of the grain and dislocation structures as well as the L12 precipitates at superplastic deformation is studied. The dynamic recrystallization at superplastic deformation is confirmed. The superplastic flow behavior of the proposed alloy is modeled via a mathematical Arrhenius-type constitutive model and an artificial neural network model. Both models exhibit good predictability at low and high strain rates of superplastic deformation.

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Effect of Strain Rate on Compressive Behavior of a Zr-Based Metallic Glass under a Wide Range of Strain Rates

Materials ◽

10.3390/ma13122861 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2861

Author(s):

Wenqing Li ◽

Tieqiang Geng ◽

Shaofan Ge ◽

Zhengwang Zhu ◽

Long Zhang ◽

...

Keyword(s):

Amorphous Alloy ◽

Yield Strength ◽

Strain Rate ◽

Amorphous Alloys ◽

High Strain ◽

Strain Rate Range ◽

Strain Rate Effect ◽

Strain Rates ◽

Compressive Behavior ◽

Rate Range

The strain rate effect on the mechanical behavior of amorphous alloys has aroused general interest. Most studies in this area have focused on quasi-static and high strain-rate compressive deformations. However, experimental results have been few, or even non-existent, under a moderate strain-rate loading. This article extends the traditional split Hopkinson pressure bar (SHPB) technique to characterize compressive deformation of an amorphous alloy at medium strain rates. The compressive behavior of Zr65.25Cu21.75Al8Ni4Nb1 amorphous alloy shows a negative strain rate effect on the yield strength with a quasi-static, moderate to high strain-rate range, and the fracture angle increases from 44° at 10−5 s−1 to 60° at 4000 s−1 as strain rate increases. Herein, we introduce a modified cooperative shear model to describe the compressive behavior of the current amorphous alloy under a broad strain rate range. The model predicts that the normalized yield strength will linearly descend with logarithmic strain rate when the strain rate is less than a critical strain rate, however, which rapidly decreases linearly with the square of the strain rate at high strain rates. The predicted data of the model are highly consistent with the current experimental results. These findings provide support for future engineering applications of amorphous alloys.

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Investigation on Mechanical Properties of GH4720Li at High Strain Rates at Wider Temperature Range

International Journal of Photoenergy ◽

10.1155/2021/8839411 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Jie Chen ◽

Haifeng Zhang ◽

Yunlong Zhang ◽

Hongtao Zhang ◽

Qingxiang Yang ◽

...

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

True Stress ◽

Strain Rates ◽

Hot Compression Test ◽

Strength And Plasticity ◽

Low Strain Rate

In this paper, the dynamic mechanical properties of GH4720Li nickel-base alloy under a large temperature range and high and low strain rates were studied by the hot compression test. The difference of mechanical properties of GH4720Li alloy under high and low strain rates was analyzed from the perspective of microstructure. The hot compression test experimental results showed that the true stress of GH4720Li alloy decreased at a low strain rate as the trial temperature elevated. Nevertheless, it was abnormal that the true stress increased at high strain rate condition as temperature elevated. By comparing the microstructure under high and low strain rates, it was found that the precipitates under low strain conditions contained a large amount of Cr (Mo). However, the content of Cr (Mo) in the precipitates at a high strain rate decreased, while the content of Fe increased. It would be concluded that Cr (Mo) would reduce the compressive strength and plasticity of GH4720Li alloy, while Fe would increase the compressive strength and plasticity of GH4720Li alloy. In addition, under the condition of a low strain rate, the shape of Cr (Mo) precipitates obtained at 20°C was lamellar, but it was spherical at 800°C. The compressive strength of GH4720Li composites with lamellar precipitates was higher than that of spherical precipitates.

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High Strain Rate Mechanical Properties of SAC-Q Between -65°C and +200°C After Exposure to Isothermal Aging

ASME 2020 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2020-2660 ◽

2020 ◽

Author(s):

Pradeep Lall ◽

Vishal Mehta ◽

Jeff Suhling ◽

Ken Blecker

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Isothermal Aging ◽

High Strain ◽

Strain Rates ◽

Solder Alloys ◽

Stress Strain ◽

Wide Range ◽

Operating Temperatures ◽

Electronic Parts

Abstract In many industries, such as automotive, oil and gas, aerospace, medical technologies, electronic parts can often be exposed to high strain loads during shocks, vibrations and drop-impact conditions. Such electronic parts can often be subjected to extreme low and high temperatures ranging from −65°C to 200°C. Also, these electronic devices can be subjected to strain rates of 1 to 100 per second in the critical environment. Recently, many doped SAC solder alloys are being introduced in the electronic component including SAC-Q, SAC-R, Innolot. SAC-Q is made with addition of Bi in Sn-Ag-Cu composition. Mechanical characteristic results and data for lead-free solder alloys are extremely important for optimizing electronic package reliability, at high temperature storage and elevated strain rates. Furthermore, the mechanical properties of solder alloys can be changed significantly due to a thermal aging, which is causing modification of microstructure. Data for the SAC-Q solder alloy with a high temp aging and testing at extreme low to high operating temperatures are not available. SAC-Q material was tested and analyzed for this study at range of operating temperatures of −65°C to 200°C and at a strain rate up to 75 per second. After the specimens were manufactured and reflowed, specimens were stored at 100°C for the isothermal aging for up to 90 days, before tensile tests were carried out at different operating temperatures. For the wide range of strain rates and test temperatures, stress-strain curves are established. In addition, the measured experimental results and data were fitted to the Anand viscoplasticity model and the Anand constants were calculated by estimating the stress-strain behavior measured in the wide range of operating temperatures and strain rates.

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AN IMAGE BASED INERTIAL IMPACT TEST TO EXTRACT VISCOELASTIC CONSTITUTIVE PARAMETERS

10.12783/asc36/35811 ◽

2021 ◽

Author(s):

ANDREW MATEJUNAS ◽

LLOYD FLETCHER ◽

LESLIE LAMBERSON

Keyword(s):

Strain Rate ◽

Polymer Matrix ◽

Mechanical Response ◽

High Strain ◽

High Rate ◽

Strain Rates ◽

High Strain Rates ◽

Full Field ◽

Viscoelastic Parameters ◽

Constitutive Parameters

Polymer matrix composites often exhibit a strong strain rate dependance in their mechanical response. In many of these materials, the viscoelastic behavior of the polymer matrix drives the rate dependence in the composite, however identifying these parameters at high strain rate presents a significant challenge. Common high-rate material characterization techniques such as the Kolsky (split-Hopkinson pressure) bar require a large test matrix across a range of strain rates. Kolsky bars also struggle to identify constitutive parameters prior to the yield due to inertial effects and the finite period of time required to reach force equilibrium. The Image Based Inertial Impact (IBII) test has been successfully used to identify linear elastic constitutive behavior of composites at high strain rates, but, to date, has only been used to extract constitutive properties at a single nominal strain rate in each test. Here, we propose an adaptation of the IBII test to identify viscoelastic parameters at high strain rates using full-field displacement data and the nonlinear virtual fields method (VFM). We validate the technique with finite element simulations of an IBII test on a model viscoelastic material that is characterized with a Prony series formulation of the generalized Maxwell model. The nonlinear VFM is then used to extract the Prony pairs for dynamic moduli and time constants from the full-field deformation data. The nonlinear viscoelastic identification allows for characterization of the evolution of mechanical response across a range of strain rates in a single experiment. The experimentally identified viscoelastic parameters of the matrix can then be used to predict the behavior of the composite at high strain rates. This approach will also be validated experimentally using a single-stage gas-gun to characterize the high-rate viscoelastic response of PMMA.

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Measurement of Mechanical Properties of St 37 Material at High Strain Rates Using a Split Hopkinson Pressure Bar

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.660.562 ◽

2014 ◽

Vol 660 ◽

pp. 562-566 ◽

Cited By ~ 1

Author(s):

Akbar Afdhal ◽

Leonardo Gunawan ◽

Sigit P. Santosa ◽

Ichsan Setya Putra ◽

Hoon Huh

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Test Specimen ◽

High Strain ◽

Split Hopkinson Pressure Bar ◽

Strain Rates ◽

Hopkinson Pressure Bar ◽

Stress Strain ◽

Split Hopkinson ◽

Pressure Bar

The dynamic mechanical properties of a material are important keys to investigate the impact characteristic of a structure such as a crash box. For some materials, the stress-strain relationships at high strain rate loadings are different than that at the static condition. These mechanical properties depend on the strain rate of the loadings, and hence an appropriate testing technique is required to measure them. To measure the mechanical properties of a material at high strain rates, ranging from 500 s-1 to 10000 s-1, a Split Hopkinson Pressure Bar is commonly used. In the measurements, strain pulses are generated in the bars system, and pulses being reflected and transmitted by a test specimen in the bar system are measured. The stress-strain curves as the material properties of the test specimen are obtained by processing the measured reflected and transmitted pulses. This paper presents the measurements of the mechanical properties of St 37 mild steel at several strain rates using a Split Hopkinson Pressure Bar. The stress-strain curves obtained in the measurement were curve fitted using the Power Law. The results show that the strength of St 37 material increases as the strain rate increases.

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A Study on the Evolution of the High Strain Rate Mechanical Properties of SAC105 Leadfree Alloy at High Operating Temperatures

Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales ◽

10.1115/ipack2015-48389 ◽

2015 ◽

Cited By ~ 6

Author(s):

Pradeep Lall ◽

Vikas Yadav ◽

Jeff Suhling ◽

David Locker

Keyword(s):

Mechanical Properties ◽

Elevated Temperature ◽

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

Lead Free ◽

Electronic Systems ◽

Strain Rates ◽

High Strain Rates ◽

Solder Interconnects

Electronics products may often be exposed to high temperature during storage, operation and handling in addition to high strain rate transient dynamic loads during drop-impact. Electronics subjected to drop-impact, shock and vibration may experience strain rates of 1–100 per sec. There are no material properties available in published literature at high strain rate at elevated temperature. High temperature and vibrations can contribute to the failures of electronic system. The reliability of electronic products can be improved through a thorough understanding of the weakest link in the electronic systems which is the solder interconnects. The solder interconnects accrue damage much faster when subjected to Shock and vibration at elevated temperatures. There is lack of fundamental understanding of reliability of electronic systems subjected to thermal loads. Previous studies have showed the effect of high strain rates and thermal aging on the mechanical properties of leadfree alloys including elastic modulus and the ultimate tensile strength. Extended period of thermal aging has been shown to affect the mechanical properties of lead free alloys including elastic modulus and the ultimate tensile strength at low strain rates representative of thermal fatigue [Lee 2012, Motalab 2012]. Previously, the microstructure, mechanical response and failure behavior of leadfree solder alloys when subjected to elevated isothermal aging and/or thermal cycling [Darveaux 2005, Ding 2007, Pang 2004] have been measured. Pang [1998] has showed that young’s modulus and yield stress of Sn-Pb are highly depending on strain rate and temperature. The ANAND viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components. Previously, Mechanical properties of lead-free alloys, at different high strain rates (10, 35, 50, 75 /sec) and elevated temperature (25 C-125 C) for pristine samples have been studied [Lall 2012 and Lall 2014]. Previous researchers [Suh 2007 and Jenq 2009] have determined the mechanical properties of SAC105 at very high strain rate (Above 1000 per sec) using compression testing. But there is no data available in published literature at high strain rate and at elevated temperature for aged conditions. In this study, mechanical properties of lead free SAC105 has been determined for high strain rate at elevated temperature for aged samples. Effect of aging on mechanical properties of SAC105 alloy a high strain rates has been studied. Stress-Strain curves have been plotted over a wide range of strain rates and temperatures for aged specimen. Experimental data for the aged specimen has been fit to the ANAND’s viscoplastic model. SAC105 leadfree alloys have been tested at strain rates of 10, 35, 50 and 75 per sec at various operating temperatures of 50°C, 75°C, 100°C and 125°C. The test samples were exposed to isothermal aging conditions at 50°C for different aging time (30, 60, and 120 Days) before testing. Full-field strain in the specimen have been measured using high speed imaging at frame rates up to 75,000 fps in combination with digital image correlation. The cross-head velocity has been measured prior-to, during, and after deformation to ensure the constancy of cross-head velocity.

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Effect of Hot Forging Strain Rate on the Microstructure and Mechanical Properties of TC4-DT Titanium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.271 ◽

2016 ◽

Vol 849 ◽

pp. 271-275 ◽

Cited By ~ 1

Author(s):

Guo Qiang Shang ◽

Xin Nan Wang ◽

Yue Fei ◽

Jing Li ◽

Li Wei Zhu ◽

...

Keyword(s):

Mechanical Properties ◽

Titanium Alloy ◽

Strain Rate ◽

Tensile Properties ◽

High Strain ◽

Hot Forging ◽

Fatigue Property ◽

Strain Rates ◽

High Fatigue ◽

Metallurgical Defects

The microstructures, tensile properties and fatigue property of TC4-DT titanium alloy hot die forged under different strain rates were investigated. The results show that the microstructures and mechanical properties of TC4-DT titanium alloy die forging using different strain rates can meet the requirement of technical standard. At the strain rates of 1mm/s and 10mm/s, the microstructure was not sensitive to the strain rate, and the alloys showed uniform, fine and fuzzy crystal grains, and no metallurgical defects. However, more uniform tensile properties in different orientations were obtained by the low strain rates (1mm/s), while the high strain rate (10mm/s) could lead to slightly increase in strength but obviously decline in ductility. High fatigue strength could be obtained by the low strain rate, but the fracture toughness and fatigue crack growth rate were not sensitive to the strain rates.

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