Mechanical characterisation of lead free solder alloys under high strain rate loads

2009 ◽  
Author(s):  
K. Meier ◽  
S. Wiese ◽  
M. Roellig ◽  
K.-J. Wolter
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Mechanical Characterisation ◽  
Free Solder

Medium to High Strain-Rate Characterization of Lead Free Solder Alloys Through Metal Cutting Experiments

2019 ◽  
Author(s):  
Yuvraj Singh ◽  
Anirudh Udupa ◽  
Srinivasan Chandrasekar ◽  
Ganesh Subbarayan
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Metal Cutting ◽  
High Strain ◽  
Lead Free ◽  
Strain Rates ◽  
Lead Free Solder ◽  
Orthogonal Metal Cutting ◽  
Free Solder

Abstract Studies on medium to high strain-rate characterization (≥ 0.1s−1) of lead-free solder are relatively few, primarily due to the lack of available methods for testing. Prior work in literature uses Split Hopkinson Bar (SPHB) experiments for high strain-rate characterization (≥ 300s−1) [1,2], while a modified micro-scale tester is used for medium strain-rate characterization (0.005s−1 to 300s−1) [3] and an impact hammer test setup for testing in a strain-rate regime from 1s−1 to 100s−1 [4]. However, there is still limited data in strain-rate regimes of relevance, specifically for drop shock applications. In this paper, we present orthogonal metal cutting as a novel method to characterize lead-free solder alloys. Experiments are carried out using a wedgelike tool that cuts through a work piece at a fixed depth and rake angle while maintaining a constant cutting velocity. These experiments are conducted at room temperature on Sn1.0Ag0.5Cu bulk test specimens with strain-rates varying from 0.32 to 48s−1. The range of strain-rates is only limited by the ball screw driven slide allowing higher strain-rates if needed. The strains and strain-rates are captured through Particle Image Velocimetry (PIV) using sequential images taken from a high-speed camera just ahead of the cutting tool. The PIV enables non-contact recording of high strain-rate deformations, while the dynamometer on the cutting head allows one to capture the forces exerted during the cutting process. Results for the stress-strain response obtained through the experiments are compared to prior work for validation. Orthogonal metal cutting is shown to be a potentially attractive method for characterization of solder at higher strain-rates.

Micro Impact Testing of Lead Free Solder Joints

2008 ◽  
Vol 32 ◽  
pp. 99-102
Author(s):  
Ranjan Rajoo ◽  
Erich H. Kisi ◽  
D.J. O'Connor
Keyword(s):  
Solder Joint ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Intermetallic Layer ◽  
Displacement Transducer ◽  
Impact Testing ◽  
Lead Free ◽  
Linear Variable Displacement Transducer ◽  
Free Solder

This paper presents data obtained from a newly-developed instrument to test the quality of solder interconnections at high strain rate – the ‘micro-impactor’. This shear test of the interconnection at high strain rate mimics the stress experienced by the solder joint when undergoing shock due to drop-impact. Instrumented with a load cell and linear variable displacement transducer (LVDT), it also has the ability to provide dynamic impact force and displacement data. Earlier concepts to characterise the solder joint at high strain rates such as the miniature pendulum impact tester [1] lacked this capability. This micro-impactor was used to study the effect of increasing silver (Ag) and copper (Cu) concentration in solder alloys on the shear strength of the solder joint. The performance of these lead-free alloys was also compared to that of the well-established leaded solder. It was found that increasing the silver content increases the yield strength of the solder, causing the failure to occur at the brittle intermetallic layer instead of in the bulk of the solder.

Evolution of Anand Parameters With Elevated Temperature Aging for SAC Leadfree Alloys

2019 ◽  
Author(s):  
Pradeep Lall ◽  
Vikas Yadav ◽  
Jeff Suhling ◽  
David Locker
Keyword(s):  
Thermal Aging ◽  
High Strain ◽  
Lead Free ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
High Strain Rates ◽  
Free Solder ◽  
Sac Solder

Abstract Electronic components in downhole oil drilling and gas industry applications, automotive and avionics may exposed to high temperatures (> 150°C) and high strain rates (1–100 per sec) during storage, operation and handling which can contribute to the failures of electronics devices. Temperatures in these applications can exceed 200°C, which is closed to melting point for SAC alloys. The microstructure for lead free solder alloys constantly evolves when subjected to thermal aging for sustained periods with accompanying degradation in mechanical properties of solder alloys. In this paper, evolution of microstructure and Anand parameters for unaged and aged SAC (SAC105 and SAC-Q) lead free solder alloys at high strain rates has been investigated induced due to thermal aging. The microstructure of the SAC solder is studied using scanning electron microscopy (SEM) for different strain rate and elevating temperature. The thermal aged leadfree SAC solder alloys specimen has been tested at high strain rates (10–75 per sec) at elevated temperatures of (25°C–200°C). The SAC leadfree solder samples were subjected to isothermal aging at 50°C up to 1-year before testing. To describe the material constitutive behavior, Anand Viscoplastic model has been used. Effect of thermal aging on Anand parameters has been investigated. In order to verify the accuracy of the model, the computed Anand parameters have been used to simulate the uniaxial tensile test. FEA based method has been used to simulate the drop events using Anand constitutive model. Hysteresis loop and Plastic work density has been computed from FEA.

Tensile Properties of Sn-Bi Lead-Free Solder Alloys

2018 ◽  
Vol 273 ◽  
pp. 72-76 ◽  
Author(s):  
Akira Yamauchi ◽  
Kenta Ida ◽  
Masahito Fukuda ◽  
Takuma Yamaguchi
Keyword(s):  
Strain Rate ◽  
Tensile Properties ◽  
Rate Sensitivity ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Ni Alloys ◽  
Fine Microstructure ◽  
Free Solder ◽  
Increasing Temperature

The Influence of alloy composition on tensile properties of Sn-Bi, Sn-Bi-Cu and Sn-Bi-Ni lead-free solder alloys were investigated. It is found that the elongation of Sn-Bi alloys depend on Bi content, and Sn-40wt% Bi alloy has the highest elongation. The addition of Cu and Ni improves the ductility of Sn 35-45wt% Bi alloys. The fine microstructure of Sn-Bi-Cu or Ni alloys have an effect on the ductility of Sn-Bi based alloys. The elongation increases with decreasing strain rate and increasing temperature. Cu and Ni added to Sn-Bi alloy showed the super plasticity behavior at low strain rate and high temperature (more than 333 K). Moreover, strain rate sensitivity ‘m’ increases with temperature.

Effect of Strain Rate on Tensile Properties of Miniature Size Specimens of Several Lead-Free Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 2810-2815 ◽  
Author(s):  
Ikuo Shohji ◽  
Yuichiro Toyama
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Strain Rate ◽  
Tensile Properties ◽  
High Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Proof Stress ◽  
Free Solder ◽  
High Temperature Solder

The effect of strain rate on tensile properties of several lead-free solder was investigated using miniature size specimens. High-temperature lead-free solder which are Sn-Cu and Sn-Sb alloys were prepared. Moreover, low-Ag lead-free solder which are Sn-1Ag-0.7Cu (SAC107, mass%) based alloys were prepared. Sn-3Ag-0.5Cu (SAC305) was also prepared for comparison. Tensile strength is proportion to the logarithm of strain rate in all solder investigated. Although 0.1% proof stress decreases at high strain rate in high-temperature solder, it scarcely changes in low-Ag solder. Elongation somewhat increases with increasing strain rate in high-temperature solder. It increases with increasing strain rate in low-Ag solder although it is lower than that of SAC305. Chisel point fracture mainly occurred except Sn-13Sb. In Sn-13Sb, brittle fracture occurred and thus elongation was lower than those of other solder. Sn-8.5Sb and Sn-1Ag-0.7Cu-1Bi-0.2In show mechanical properties similar to SAC305.

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