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

2016 ◽  
Vol 849 ◽  
pp. 271-275 ◽  
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.

Impact tensile behavior and frequency response of 3D braided composites

2011 ◽  
Vol 82 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Xuehui Gan ◽  
Jianhua Yan ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Tensile Properties ◽  
High Strain ◽  
Tensile Modulus ◽  
Tensile Failure ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Braided Composites ◽  
3D Braided Composites

The uniaxial tensile properties of 4-step 3D braided E-glass/epoxy composites under quasi-static and high-strain rate loadings have been investigated to evaluate the tensile failure mode at different strain rates. The uniaxial tensile properties at high strain rates from 800/s to 2100/s were tested using the split Hopkinson tension bar (SHTB) technique. The tensile properties at quasi-static strain rate were also tested and compared with those in high strain rates. Z-transform theory is applied to 3D braided composites to characterize the system dynamic behaviors in frequency domain. The frequency responses and the stability of 3D braided composites under quasi-static and high-strain rate compression have been analyzed and discussed in the Z-transform domain. The results indicate that the stress-strain curves are rate sensitive, and tensile modulus, maximum tensile stress and corresponding tensile strain are also sensitive to the strain rate. The tensile modulus, maximum tensile stress of the 3D braided composites are linearly increased with the strain rate. With increasing of the strain rate (from 0.001/s to 2100/s), the tensile failure of the 3D braided composite specimens has a tendency of transition from ductile failure to brittle failure. The magnitude response and phase response is very different in quasi-static loading with that in high-strain rate loading. The 3D braided composite system is more stable at high strain rate than quasi-static loading.

Effect of High Strain-Rate Thermomechanical Processing on Microstructure and Mechanical Properties of Ti-10V-2Fe-3Al Alloy

2013 ◽  
Vol 845 ◽  
pp. 96-100 ◽  
Author(s):  
Piotr Skubisz ◽  
Marek Packo ◽  
Katarzyna Mordalska ◽  
Tadeusz Skowronek
Keyword(s):  
Mechanical Properties ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Thermomechanical Processing ◽  
Hot Forging ◽  
High Strength ◽  
Processing Route ◽  
Microstructure And Mechanical Properties ◽  
Processed Material

Results of beta forging of titanium alloy Ti-10V-2Fe-3Al and subsequent thermal treatment are presented, with analysis of the effect of the processing route on the final mechanical properties, correlated with microstructure of thermomechanically processed material. Investigation of response to high strain-rate hot-forging of microstructure and mechanical properties is focused on the effect of the strengthening mechanisms in the material after two common manners of deformation typical of that alloy. The effect of deformation conditions on final microstructure and mechanical properties was analyzed in three crucial stages of thermomechanical processing, e.i. after deformation, quenching and aging. In result, conclusions were formulated as for processing conditions promoting high strength and/or ductility.

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

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.

scholarly journals Effect of Fiber Blending Ratio on the Tensile Properties of Steel Fiber Hybrid Reinforced Cementitious Composites under Different Strain Rates

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4504
Author(s):  
Minjae Son ◽  
Gyuyong Kim ◽  
Hongseop Kim ◽  
Sangkyu Lee ◽  
Yaechan Lee ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Synergistic Effect ◽  
Strain Rate ◽  
Tensile Properties ◽  
High Performance ◽  
Steel Fiber ◽  
High Strain ◽  
Strain Rates ◽  
Cementitious Composite ◽  
Hybrid Fiber

In this study, a high-performance hybrid fiber-reinforced cementitious composite (HP-HFRCC) was prepared, by mixing hooked steel fiber (HSF) and smooth steel fiber (SSF) at different blending ratios, to evaluate the synergistic effect of the blending ratio between HSF and SSF and the strain rate on the tensile properties of HP-HFRCC. The experimental results showed that the micro- and macrocrack control capacities of HP-HFRCC varied depending on the blending ratio and strain rate, and the requirement for deriving the appropriate blending ratio was confirmed. Among the HP-HFRCC specimens, the specimen mixed with HSF 1.0 vol.% and SSF 1.0 vol.% (H1.0S1.0) exhibited a significant increase in the synergistic effect on the tensile properties at the high strain rate, as SSF controlled the microcracks and HSF controlled the macrocracks. Consequently, it exhibited the highest strain rate sensitivities of tensile strength, strain capacity, and peak toughness among the specimens evaluated in this study.

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

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.

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

2014 ◽  
Vol 660 ◽  
pp. 562-566 ◽  
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.

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

2015 ◽  
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.

Effect of Strain Rate on Tensile Properties of Injection Molded Multiwall Carbon Nanotube Reinforced PA 6/6 Nanocomposites

2020 ◽  
Author(s):  
Seyed Hamid Reza Sanei ◽  
Hanna Drozynski ◽  
Dakota Hetrick
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Strain Rate ◽  
Tensile Properties ◽  
Loading Rate ◽  
Multiwall Carbon Nanotube ◽  
Strain Rates ◽  
Chain Mobility ◽  
Injection Molded ◽  
Multiwall Carbon

Abstract The mechanical properties of polymers highly depend on the loading rate, however, the effect of loading/strain rate with the addition of Carbon Nanotube is not well understood. In this study, the effect of Carbon Nanotube (CNT) content on the rate dependence of polymers was studied. Injection molded mini-tensile samples with CNT content ranging from 0 to 15wt% at strain rates of .0006, .0013, .0019 and .0025 s−1 were tested. It was found that as strain rate increased, the ultimate strength and Young s Modulus of the tensile specimens increased. It was also shown that addition of CNT will lower the chain mobility of polymer and lower the polymer dependence of properties to strain rates.

Effect of Strain Rate on Tensile Properties of Tissues in Tail Flukes of Dolphin

2010 ◽  
Vol 43 ◽  
pp. 453-456
Author(s):  
Qi Long Sun ◽  
Hirohisa Morikawa ◽  
Shunichi Kobayashi ◽  
Keiichi Ueda ◽  
Hirokazu Miyahara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Connective Tissue ◽  
Strain Rate ◽  
Tensile Properties ◽  
Strain Rates ◽  
Dense Connective Tissue ◽  
Propulsive Performance

The mechanical properties of the tissues relates with the propulsive performance of the tail fins of dolphins. In this study, the tensile properties of the main two tissues in the tail flukes of a dolphin, that is, the ligamentous layer and dense connective tissue are investigated. As a result, the tissues all showed the effect of the strain rate which weakened gradually as the strain increased. The moduli obtained at different strain rates tend to converge.

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