High Temperature High Strain-Rate Tensile and Compressive Deformation Behaviors of Cu-Zn-Sn-Al Alloy

2015 ◽  
Vol 817 ◽  
pp. 55-62
Author(s):  
Qiang Song Wang ◽  
Dong Mei Liu ◽  
Guo Liang Xie ◽  
Wei Bin Xie ◽  
Yang Li ◽  
...  
Keyword(s):  
High Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Al Alloy ◽  
Softening Effect ◽  
Α Phase ◽  
Hardening Effect ◽  
Deformation Behaviors ◽  
Strain Rate Hardening

The present work gives a systematic study on the high temperature and high strain-rate deformation behaviors of a two-phase α/β Cu-Zn-Sn-Al alloy, by combining the split Hopkinson bar experiments and microstructural investigations. The results show that under high strain-rate, both the dislocation slip and deformation twins within the α phase contribute to the plastic strengthening of Cu-Zn-An-Al alloy, resulting in the strain-rate-hardening effect. As the deformation temperature increases, the shapes of the stress-strain curves are mainly influenced by the temperature-softening effect and the dynamic recrystallization of the α phase. Finally, material constants regarding the strain-rate-hardening and temperature-softening effects are determined, based on the Johnson-Cook constitutive model. The results show that compared with other metallic materials, the present Cu-Zn-Sn-Al alloy has a relatively stronger strain-rate-hardening effect and weaker temperature-softening effect.

High-Strain-Rate Response of a Specially-Made Copper Sample

2015 ◽  
Vol 817 ◽  
pp. 35-41
Author(s):  
Dong Mei Liu ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Wei Bin Xie ◽  
Yang Li ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Temperatures ◽  
High Strain ◽  
Copper Sample ◽  
Dislocation Slip ◽  
Softening Effect ◽  
Hardening Effect ◽  
Dynamic Recrystallization Behavior ◽  
Strain Rate Hardening

In the present study, a systematic study on both the high strain-rate tensile and compressive deformation behaviors of a specially-made copper sample have been carried out at different high temperatures, by using the split Hopkinson bar experiments. The Johnson-Cook constitutive model was used to model the high strain-rate responses of the specimen at high temperatures. The results showed that compared with other metallic materials, the specially-made copper sample had a relatively stronger strain-rate-hardening effect and weaker temperature-softening effect. Evolution of the microstructure suggests that under high strain-rate, both the dislocation slip and deformation twins contribute to the plastic strengthening of the copper specimen, resulting in the strain-rate-hardening effect. And the dynamic recrystallization behavior plays an important role during the high strain-rate deformation process at the high temperatures.

Study on Dynamic Mechanical Response of TC21 Alloy

2011 ◽  
Vol 88-89 ◽  
pp. 674-678
Author(s):  
Shuang Zan Zhao ◽  
Xing Wang Cheng ◽  
Fu Chi Wang
Keyword(s):  
Flow Stress ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Hardening ◽  
High Strain ◽  
Dynamic Flow ◽  
Dynamic Mechanical ◽  
Hardening Effect ◽  
High Strain Rate Deformation ◽  
Binary Morphology

Some results of an experimental study on high strain rate deformation of TC21 alloy are discussed in this paper. Cylindrical specimens of the TC21 alloys both in binary morphology and solution and aging morphology were subjected to high strain rate deformation by direct impact using a Split Hopkinson Pressure Bar. The deformation process is dominated by both thermal softening effect and strain hardening effect under high strain rate loading. Thus the flow stress doesn’t increase with strain rate at the strain hardening stage, while the increase is obvious under qusi-static compression. Under high strain rate, the dynamic flow stress is higher than that under quasi-static and dynamic flow stress increase with the increase of the strain rate, which indicates the strain rate hardening effect is great in TC21 alloy. The microstructure affects the dynamic mechanical properties of TC21 titanium alloy obviously. Under high strain rate, the solution and aging morphology has higher dynamic flow stress while the binary morphology has better plasticity and less prone to be instability under high strain rate condition. Shear bands were found both in the solution and aging morphology and the binary morphology.

Viscoplastic Constitutive Model for High Strain Rate Mechanical Properties of SAC-Q Leadfree Solder After High-Temperature Prolonged Storage

2018 ◽  
Author(s):  
Pradeep Lall ◽  
Vikas Yadav ◽  
Jeff Suhling ◽  
David Locker
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
Thermal Aging ◽  
High Strain ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Aging Effects ◽  
Model Predictions

Electronics in automotive underhood and downhole drilling applications may be subjected to sustained operation at high temperature in addition to high strain-rate loads. SAC solders used for second level interconnects have been shown to experience degradation in high strain-rate mechanical properties under sustained exposure to high temperatures. Industry search for solutions for resisting the high-temperature degradation of SAC solders has focused on the addition of dopants to the alloy. In this study, a doped SAC solder called SAC-Q solder have been studied. The high strain rate mechanical properties of SAC-Q solder have been studied under elevated temperatures up to 200°C. Samples with thermal aging at 50°C for up to 6-months have been used for measurements in uniaxial tensile tests. Measurements for SAC-Q have been compared to SAC105 and SAC305 for identical test conditions and sample geometry. Data from the SAC-Q measurements has been fit to the Anand Viscoplasticity model. In order to assess the predictive power of the model, the computed Anand parameters have been used to simulate the uniaxial tensile test and the model predictions compared with experimental data. Model predictions show good correlation with experimental measurements. The presented approach extends the Anand Model to include thermal aging effects.

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