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Showing 1 to 20 of 74 for “"lead free"”.
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High Performance Lead--free Piezoelectric Materials
… and energy harvesting devices. A number of lead-based perovskite compositions (PZT, PMN-PT, PZN-PT etc.) have dominated the field in last few decades owing to their giant piezoresponse and convenient application relevant tunability. With increasing environmental concerns, in the last one …
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Lead - Free Piezoelectric Based Magnetoelectric Composites
… is to design, synthesize and characterize lead-free piezoelectric based magnetostrictive components based magnetoelectric (ME) composites that exhibit self-bias characteristics and high amplitude of ME coupling. The secondary goal of this thesis was to lay down the foundation for nanoscale …
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Lead-Free Gunshot Residues as Forensic Evidence
… However, the manufacture and distribution of lead-free alternatives to small caliber firearms ammunition is increasing rapidly as these types of rounds are more environmentally friendly and safer for use in indoor shooting ranges. Removing lead-containing compounds (e.g., lead styphnate) from …
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Drop Impact Reliability Testing Lead-Free Chip Scale Packages
… Hazardous Substances (RoHS) and other countries' lead-free directives banned the use of lead in consumer electronics products. While this is a responsible environmental change for the electronics industry, it requires the introduction of new solders and soldering processes, and signals a major …
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Synthesis-Structure-Property Relationships in Lead-Free Piezoelectric Materials
… most of these piezoelectric materials utilize lead-based systems which are becoming serious problem owing to the restrictions imposed by regulatory agencies across the globe. In the functional ceramics community, currently there is no problem more important than to find a replacement for …
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Strain-rate Dependent Fracture Load Prediction of Lead-free Solder Joints
The critical strain energy release rate at crack initiation, Jci, has been shown to govern the fracture of short solder joints. The present work measured Jci for 2 mm long SAC305 solder joints as a function of the strain rate and phase angle using DCB specimens. A drop tester was designed and built …
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Lead-free solders for high-reliability applications: high-cycle fatigue studies
The use of lead (Pb) in solders for electronic connections is now extensively restricted in Europe, with its use likely to be phased out completely in the medium term. Although Pb-free solders have been the subject of much research, little investigation has been carried out into their reliability …
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Octane requirement increase arising from the use of lead free fuel
Lead in petrol has been identified as a health hazard and attempts are being made to create a lead-free atmosphere. Through an intensive study a review is made of the various options available to the automobile and petroleum industry. The economic and atmospheric penalties coupled with automobile …
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Effect of temperature on the fracture behavior of lead-free solder joints
The objective of the present study is to examine the effect of temperature on the fracture behavior of Cu-SAC305-Cu joints. To this end, double cantilever beam (DCB) specimens, consisting of a thin layer of Sn96.5Ag3.0Cu0.5 (SAC305) solder sandwiched between two copper bars, fabricated under …
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New modalities for strain engineering of lead-free perovskite ferroelectric thin films
… attention has been given to the development of lead-based ferroelectric systems such as PbZr1-xTixO3 due to their robust high temperature ferroelectric properties, as well as the presence of the so-called morphotropic phase boundary (MPB) ̶ a temperature-independent composition-driven structural …
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High temperature ultrasonic gas flow sensor based on lead free piezoelectric material
… is put forward. A novel and highly enhanced, lead free piezoelectric material, suitable for continuous operation at temperatures above 400 °C has been engineered for ultrasonic gas velocity sensor applications. Structural modification of pure bismuth titanate (Bi4Ti3O12) or BIT compound, …
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High-strain actuation of lead-free perovskites : compositional effects, phenomenology and mechanism
… has been mapped by means of a Landau type free energy expansion. A nanodomain relaxation mechanism of frequency dependent electromechanical response of BNBZT has been suggested and is supported by optical and transmission electron microscopy.
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Structural Study of Heterogeneous States in Lead-free NBT-based Single Crystals
… are requiring industries to develop non-lead-based compositions of ferroelectric and piezoelectric materials. These materials—now widely used in sensors, actuators, and transducers—are for the most part lead-based compounds such as Pb(Zr,Ti)O₃ (PZT). Indeed, PZT represents the dominant …
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Experimental and modelling studies of electronic packaging interconnections formed with lead-free materials
… films (ACFs). The wetting behaviours of new lead-free solders (i.e. Sn-2.8Ag-0.5Cu-1.0Bi and Sn-0.7Cu-0.3Ni) have been evaluated using the wetting balance test. This assessment ahs been performed for three soldering temperatures with three different types of fluxes. The results have been …
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Microstructural Evolution in Thermally Cycled Large-Area Lead and Lead-Free Solder Joints
… forces for considering alternative materials to lead- based products, specifically interconnections, in electronics applications, including the impending legislation or regulations which may tax, restrict, or eliminate the use of lead and the trend toward advanced interconnection technology, …
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Strain-phase relations in lead-free ferroelectric KxNa1-xNbO3 epitaxial films for domain engineering
… phases has been pointed out. As an exemplary lead-free material, potassium sodium niobate (KxNa1-xNbO3) is considered. This material is of high technological interest due to its large coupling constant and Curie temperature. Furthermore, calculations predict the appearance of monoclinic phases …
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Creep behaviour of the ternary lead-free solder alloy : Sn-3.8wt.%Ag-0.7wt.%Cu
… of both miniaturisation and the need to replace lead in interconnections. In service, interconnections generally fail by thermomechanical fatigue, and this behaviour is strongly affected by the creep process. This thesis examines the creep behaviour of a popular lead-free replacement alloy, …
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Lewis-base Thioacetamide assisted crystallization of lead-free perovskite solar Cells for improved Efficiency
… in cutting-edge perovskite solar cells include lead, which has been linked to health risks for people and other living organisms. Accordingly, the developing front in photovoltaic research is the discovery and development of new lead-free perovskite materials for the future global …
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