Creep and High-Temperature Isothermal Fatigue of Pb-Free Solders

2003 ◽  
Author(s):  
Qian Zhang ◽  
Abhijit Dasgupta ◽  
Peter Haswell
Keyword(s):  
High Temperature ◽  
Strain Range ◽  
Inelastic Strain ◽  
Propagation Rate ◽  
Mechanical Tests ◽  
Test System ◽  
Load Drop ◽  
Homologous Temperature ◽  
Free Solder ◽  
Sn37pb Solder

The creep resistance of Sn3.9Ag0.6Cu Pb-free solder alloy is compared to that of the baseline eutectic Sn37Pb solder at comparable homologous temperatures. Sn3.9Ag0.6Cu is significantly more creep-resistant than Sn37Pb solder. The isothermal cyclic mechanical durability of Sn3.5Ag and Sn3.9Ag0.6Cu Pb-free solder alloys are presented and compared to that of the baseline eutectic Sn37Pb solder at comparable homologous temperature. Cyclic mechanical tests are performed at high temperature at various strain-rates and load levels, using a thermo-mechanical-microstructural (TMM) test system developed by the authors. The data is analyzed using standard power-law durability models based on 50% load drop, using cyclic work and cyclic inelastic strain range. The durability curve of Sn3.9Ag0.6Cu Pb-free solder is found to have the largest slope, followed by the Sn3.5Ag solder and finally the baseline Sn37Pb eutectic solder, under the test conditions investigated. At a homologous temperature of 0.75, Sn3.9Ag0.6Cu shows the best durability, while Sn3.5Ag and Sn37Pb have very similar durability performance according to damage relations based on either work or inelastic strain range. The damage propagation rate is also estimated for all three solders, based on the load drop rate, and plotted vs. cyclic work and cyclic inelastic strain range.

Cyclic Mechanical Durability of Sn3.0Ag0.5Cu Pb-Free Solder Alloy

2005 ◽  
Author(s):  
Gayatri Cuddalorepatta ◽  
Abhijit Dasgupta
Keyword(s):  
Room Temperature ◽  
Strain Range ◽  
Cyclic Strain ◽  
Inelastic Strain ◽  
Mechanical Tests ◽  
Test System ◽  
Snagcu Solder ◽  
Mechanical Durability ◽  
Free Solder

The isothermal mechanical durability properties of a hypoeutectic, Sn3.0Ag0.5Cu solder are presented and compared to that of near-eutectic Sn3.9Ag0.6Cu and of baseline eutectic Sn37Pb solder. Cyclic mechanical tests are performed at room temperature at various load levels, using a custom-built thermo-mechanical-microscale (TMM) test system. Both the SnAgCu solders are found to outperform the baseline Sn37Pb, with near-eutectic Sn3.9Ag0.6Cu having the best durability. These trends are found to be in agreement with similar results available in the literature for thermal cycling durability. Fatigue results are presented in terms of both cyclic strain range and cyclic work dissipation. The effect of microstructural coarsening resulting from long-term aging at room temperature is investigated by conducting similar tests at room temperature, on the aged samples. The durability of the hypoeutectic SnAgCu solder reduced on aging, with the drop being more significant for damage curves based on cyclic work dissipation, than on cyclic inelastic strain range.

Cyclic Mechanical Durability of Sn-3.9Ag-0.6Cu and Sn-3.5Ag Lead-Free Solder Alloys

2002 ◽  
Author(s):  
Qian Zhang ◽  
Abhijit Dasgupta ◽  
Peter Haswell
Keyword(s):  
Thermal Cycling ◽  
Strain Range ◽  
Mechanical Tests ◽  
Test System ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Mechanical Cycling ◽  
Mechanical Durability ◽  
Free Solder

The isothermal mechanical durability properties of two lead-free solder alloys, Sn3.5Ag and Sn3.9Ag0.6Cu, are presented and compared to that of the baseline eutectic Sn37Pb solder. Cyclic mechanical tests are performed at room temperature at various strain-rates and load levels, using a thermo-mechanical-microstructural (TMM) test system developed by the authors. The data is analyzed using standard power-law durability models based on work and inelastic strain range. The Sn3.9Ag0.6Cu lead-free alloy is found to be most durable, followed by the Sn3.5Ag solder and finally the baseline Sn37Pb eutectic alloy, under the test conditions investigated. However, tests at high load levels show a greater difference in durability than tests at low load levels. This trend is the opposite of that reported in the literature for thermal cycling durability. A hypothesis is put forward to explain the observed differences between mechanical cycling and thermal cycling, based on the energy-partitioning damage model.

G0300101 Proposal of Acquisition Way of Inelastic Strain Range Using Lead-Free Solder Lap Joint Type Shear Specimen

2015 ◽  
Vol 2015 (0) ◽  
pp. _G0300101--_G0300101-
Author(s):  
Takeharu HAYASHI ◽  
Hirohiko WATANABE ◽  
Yoshinori EBIHARA ◽  
Jyo SHIMURA
Keyword(s):  
Strain Range ◽  
Inelastic Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Lap Joint ◽  
Shear Specimen ◽  
Free Solder

Isothermal Mechanical Durability of Three Selected PB-Free Solders: Sn3.9Ag0.6Cu, Sn3.5Ag, and Sn0.7Cu

2005 ◽  
Vol 127 (4) ◽  
pp. 512-522 ◽  
Author(s):  
Qian Zhang ◽  
Abhijit Dasgupta ◽  
Peter Haswell
Keyword(s):  
Strain Rate ◽  
Room Temperature ◽  
Strain Range ◽  
Inelastic Strain ◽  
Total Strain Range ◽  
Homologous Temperature ◽  
Test Conditions ◽  
Mechanical Durability ◽  
Virtual Qualification ◽  
The Eu

This study is motivated by the urgent need in the electronics industry for mechanical properties and durability of Pb-free solders because the use of Pb will be banned in the EU by July 1, 2006. The isothermal mechanical durability of three NEMI recommended Pb-free solders, 95.5Sn-3.9Ag-0.6Cu, 96.5Sn-3.5Ag, and 99.3Sn-0.7Cu, is tested on the thermo-mechanical-microscale (TMM) setup under two test conditions: room temperature and relatively high strain rate, and high temperature and low strain rate. The test data are presented in a power law relationship between three selected damage metrics (total strain range, inelastic strain range, and cyclic work density) to 50% load drop. The obtained mechanical durability models of three Pb-free solders are compared with those of the eutectic 63Sn-37Pb solder at the two selected test conditions and at the same homologous temperature of 0.75. The results of this study can be used for virtual qualification of Pb-free electronics during design and development of electronics under mechanical loading.

scholarly journals Experimental research of loading rate effect on brittle-ductile transition of mudstone under high temperature

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 959-965
Author(s):  
Lianying Zhang ◽  
Chao Ma ◽  
Zhongqiang Zhang ◽  
Bing Li ◽  
Lei Lei
Keyword(s):  
High Temperature ◽  
Experimental Research ◽  
Loading Rate ◽  
Mechanical Tests ◽  
Test System ◽  
Yield Strain ◽  
Brittle Ductile Transition ◽  
High Temperature Furnace ◽  
Hydraulic Servo ◽  
Temperature Furnace

To investigate the brittle ductile transformation characteristics of mudstone under high temperature, the MTS810 electro mechanical hydraulic servo test system and matched high temperature furnace MTS652.02 are used to perform mechanical tests to study the influence of loading rate on the yield strain and ductility coefficient of the mudstone at high temperatures.

The Microstructure and Mechanical Properties of Ni-Based Superalloy after Service Exposure in Gas Turbine

2010 ◽  
Vol 654-656 ◽  
pp. 2523-2526 ◽  
Author(s):  
Keun Bong Yoo ◽  
Han Sang Lee
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Mechanical Tests ◽  
Time Dependent ◽  
Second Stage ◽  
Degradation Analysis ◽  
Check Points ◽  
Tcp Phase ◽  
Service Exposure ◽  
High Temperature Tensile

Many investigations about superalloys and coatings have been done in the laboratory, but evaluating the degradation condition of hot section components during service is still important not only for repair and reuse but also for outage prevention. Time dependent degradation for second stage blades of gas turbine was investigated. The degradation analysis for used blades was divided into microstructure changes by position of the blade and mechanical tests of high temperature tensile test. In the microstructure analysis, the rafting and coarsening of γ', MC decomposition and TCP phase formation occurred and progressed with increasing service time, and especially the leading and trailing edge of top layer should be a check points for used blade. High temperature tensile results of 25,000 and 52,000 hrs used blades were also compared with serviced time and position in each blade.

Microphone High-Temperature Test System Development Based on PID Control

2014 ◽  
Vol 912-914 ◽  
pp. 1294-1298
Author(s):  
Li Yan Zhao
Keyword(s):  
High Temperature ◽  
System Development ◽  
Test System ◽  
Lower Efficiency ◽  
Temperature Function ◽  
Control Center ◽  
Marketing Application ◽  
High Temperature Operation ◽  
Very High ◽  
Temperature Test

With PID as its control center, this system overcomes the uncontrol of temperature, lower efficiency, difficult operation and other drawbacks occurring in precious microphone high-temperature test system. Characterized by excellent adaptability, automatic heating and constant temperature function, and simple operation, the high-temperature test system can meet the special requirements during microphone high temperature operation, evaluate the phase, frequency response, background noise and other product indexes in a high temperature ambient, and possess a very high marketing application value.

scholarly journals The Influences Which Constitutive Models for Lead-Free Solder Alloys in General FEA Programs Give to Accumulated Inelastic Strain Behavior

2016 ◽  
Vol 5 (4) ◽  
pp. 266-274
Author(s):  
Takeharu HAYASHI ◽  
Hirohiko WATANABE ◽  
Masaaki TAKABE ◽  
Yoshinori EBIHARA ◽  
Tatsuhiko ASAI ◽  
...  
Keyword(s):  
Constitutive Models ◽  
Inelastic Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Strain Behavior ◽  
Free Solder

Mullite Whisker Reinforced Zirconia Toughened Alumina for High Temperature Applications

2014 ◽  
Author(s):  
Taylor Robertson ◽  
Xiao Huang ◽  
Richard Kearsey
Keyword(s):  
High Temperature ◽  
Cost Effective ◽  
Mechanical Tests ◽  
Processing Route ◽  
Molten Salt Method ◽  
The Matrix ◽  
Mullite Whiskers ◽  
Monolithic Ceramics ◽  
Zirconia Toughened Alumina ◽  
Temperature Applications

Particulate enhanced oxide ceramics are an attractive class of materials for high temperature applications because they possess many of the high temperature capabilities of monolithic ceramics but also have enhanced mechanical properties due to their multi-phase structure. High temperature structural ceramics have the potential to operate above at higher temperatures than current super alloys; however, processing costs and lack of reliability has prevented their commercialization. In this work a particulate reinforced ceramic composed entirely of oxides is proposed as a more oxidation resistant and cost effective structural ceramic which will have potentially improved resistance to environmental degradation. Zirconia Toughened Alumina (ZTA), as the matrix, has enhanced toughness, strength, and creep resistance over single phase alumina or zirconia. ZTA can further be strengthened by the incorporation of SiC type whiskers; however, these whiskers are prone to deterioration at temperatures above 1000°C through oxidation. In this work Mullite, in whisker form, is proposed as the reinforcement to ZTA due to its stability in oxidizing atmospheres at high temperatures. Mullite whiskers are grown through the molten salt method and incorporated into the ZTA matrix using a colloidal processing route in this study. The composition of the ZTA matrix is 15wt% Yttria stabilized Zirconia (YSZ), 85 wt% α-Alumina. The Mullite whiskers make up 20 vol% of the composite, yielding a final composition of 71.6 wt% Alumina, 12.7 wt% YSZ, and 15.6 wt% Mullite. The green compacts are fired in a two stage sintering process incorporating atmospheric pressure sintering to 92% density (seal the pore channels) and then hot isostatic pressure pressing (HIP) to increase the density. Samples have been tested for room temperature flexural strength using a three point bend test and fracture toughness through Gong’s Vickers indentation method. The results of microstructure study and mechanical tests are reported in this paper.

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