Tensile Behaviors of Lead-Containing and Lead-Free Solders at High Strain Rates

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Fei Qin ◽  
Tong An ◽  
Na Chen ◽  
Jie Bai
Keyword(s):  
High Strain ◽  
Lead Free ◽  
Strain Rates ◽  
High Strain Rates ◽  
Reliability Design ◽  
Split Hopkinson Tensile Bar ◽  
Rate Dependent ◽  
Before And After ◽  
Split Hopkinson ◽  
Lead Free Solders

Behavior of solder joints in microelectronic packages is crucial to the drop impact reliability design of mobile electronic products. In this paper, tensile behaviors of Sn37Pb, Sn3.5Ag, and Sn3.0Ag0.5Cu at strain rates of 600 s−1, 1200 s−1, and 1800 s−1 were investigated using the split Hopkinson tensile bar experimental technique. Stress-strain curves of the three solders were obtained, and microstructure and fractography of the specimens before and after the tests were examined and presented. The experimental results show that the lead-free solders are strongly strain rate dependent: Their tensile strength, percent elongation, and percent reduction in area are much greater than those properties of the lead-containing solder at high strain rates.

Strain Rate Effects and Rate-Dependent Constitutive Models of Lead-Based and Lead-Free Solders

2009 ◽  
Vol 77 (1) ◽  
Author(s):  
Fei Qin ◽  
Tong An ◽  
Na Chen
Keyword(s):  
Strain Rate ◽  
Impact Analysis ◽  
Solder Joints ◽  
High Strain ◽  
Drop Impact ◽  
Lead Free ◽  
Strain Rates ◽  
High Strain Rates ◽  
Rate Dependent ◽  
Lead Free Solders

As traditional lead-based solders are banned and replaced by lead-free solders, the drop impact reliability is becoming increasingly crucial because there is little understanding of mechanical behaviors of these lead-free solders at high strain rates. In this paper, mechanical properties of one lead-based solder, Sn37Pb, and two lead-free solders, Sn3.5Ag and Sn3.0Ag0.5Cu, were investigated at strain rates that ranged from 600 s−1 to 2200 s−1 by the split Hopkinson pressure and tensile bar technique. At high strain rates, tensile strengths of lead-free solders are about 1.5 times greater than that of the Sn37Pb solder, and also their ductility are significantly greater than that of the Sn37Pb. Based on the experimental data, strain rate dependent Johnson–Cook models for the three solders were derived and employed to predict behaviors of solder joints in a board level electronic package subjected to standard drop impact load. Results indicate that for the drop impact analysis of lead-free solder joints, the strain rate effect must be considered and rate-dependent material models of lead-free solders are indispensable.

Effects of High Strain Rates on Ductile Slant Fracture Behaviour of Pipeline Steel: Experiments and Modelling

2016 ◽  
Author(s):  
Reza Hojjati ◽  
Matthias Steinhoff ◽  
Steven Cooreman ◽  
Filip Van den Abeele ◽  
Patricia Verleysen
Keyword(s):  
Ductile Fracture ◽  
High Strain ◽  
Fracture Behaviour ◽  
Pipeline Steel ◽  
Numerical Approach ◽  
Strain Rates ◽  
High Strain Rates ◽  
X70 Pipeline Steel ◽  
Split Hopkinson Tensile Bar ◽  
Split Hopkinson

Good material properties are required to ensure the safe and reliable design of oil and gas transmission pipelines. The main objective of the study, presented in this paper, is to examine the influence of high strain rates on the hardening and ductile fracture behaviour of an API 5L X70 pipeline steel by means of a combined experimental/numerical approach. For this purpose, the impact toughness of the material is assessed using instrumented Charpy V-notch (CVN) impact tests at a wide range of temperatures. To characterize the mechanical response of an X70 pipeline steel subjected to high strain rates, split Hopkinson tensile bar (SHTB) experiments are performed. These experiments allow deriving the true effective stress versus plastic strain, strain rate and temperature. Both the CVN and SHTB tests results are used for fundamental material research and constitutive material modelling. For the numerical simulations, the modified Bai-Wierzbicki (MBW) model is applied. The MBW model represents the influence of the stress state on the plastic behaviour and the onset of damage, and quantifies the microstructure degradation using a dissipation-energy based damage evolution law. The model hence allows for an accurate prediction of the ductile fracture mechanisms. The combined experimental/numerical approach is then used to simulate the upper shelf ductile fracture behaviour of an API X70 pipeline steel for high strain rate and Charpy tests. Based on the available experimental data, a new parameter set has been determined. Using these new material parameters, good correlations between numerical simulations and experimental observations have been obtained for both the split Hopkinson tensile bar tests and the Charpy impact tests.

Studies on Rate-dependent Macro-damage Evolution of Materials at High Strain Rates

2010 ◽  
Vol 19 (7) ◽  
pp. 805-820 ◽  
Author(s):  
Li-Li Wang ◽  
Feng-Hua Zhou ◽  
Zi-Jian Sun ◽  
Yong-Zhong Wang ◽  
Shao-Qiu Shi
Keyword(s):  
Damage Evolution ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Rate Dependent

scholarly journals A rate-dependent Hosford-Coulomb model for predicting ductile fracture at high strain rates

2015 ◽  
Vol 94 ◽  
pp. 01080 ◽  
Author(s):  
Stephane J. Marcadet ◽  
Christian C. Roth ◽  
Borja Erice ◽  
Dirk Mohr
Keyword(s):  
Ductile Fracture ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Rate Dependent ◽  
Coulomb Model

Using Split Hopkinson Pressure Bars to Perform Large Strain Compression Tests on Neoprene at Intermediate and High Strain Rates

2013 ◽  
Vol 631-632 ◽  
pp. 458-462 ◽  
Author(s):  
Peng Duo Zhao ◽  
Yu Wang ◽  
Jian Ye Du ◽  
Lei Zhang ◽  
Zhi Peng Du ◽  
...  
Keyword(s):  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Large Strain ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
Split Hopkinson ◽  
Pressure Bar

The strain rate sensitivity of neoprene is characterized using a modified split Hopkinson pressure bar (SHPB) system at intermediate (50 s-1, 100 s-1) and high (500 s-1, 1000 s-1) strain rates. We used two quartz piezoelectric force transducers that were sandwiched between the specimen and experimental bars respectively to directly measure the weak wave signals. A laser gap gage was employed to monitor the deformation of the sample directly. Three kinds of neoprene rubbers (Shore hardness: SHA60, SHA65, and SHA70) were tested using the modified split Hopkinson pressure bar. Experimental results show that the modified apparatus is effective and reliable for determining the compressive stress-strain responses of neoprene at intermediate and high strain rates.

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