Microstructure of Sn-20In-2.8Ag solder and mechanical properties of joint with Cu

2019 ◽  
Vol 31 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Fen Peng ◽  
Wensheng Liu ◽  
Yunzhu Ma ◽  
Chaoping Liang ◽  
Yufeng Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Reaction ◽  
Scanning Calorimetry ◽  
Good Reliability ◽  
Content Type ◽  
Dsc Measurements ◽  
Lap Shear ◽  
Evolution Characteristics ◽  
Three Phase ◽  
Melting And Solidification

Purpose To explore substitutes for traditional Sn-Pb solder, Sn-20In-2.8Ag was considered because of its appropriate melting temperature, good reliability and high ductility at less than 100°C. However, the mechanical properties of Sn-20In-2.8Ag were not satisfactory. The reason for the poor mechanical properties of the Sn-20In-2.8Ag/Cu joint was revealed, and a way to solve the problem was found. Design/methodology/approach The microstructure evolution, characteristics of melting and solidification and joining performance with Cu were investigated using scanning electron microscopy (SEM), electron probe microanalysis, differential scanning calorimetry (DSC) and mechanical testing. Findings SEM results showed that the microstructure of Sn-20In-2.8Ag was composed of coarse dendritic Ag2In and γ phases, with Ag2In distributed at the grain boundaries. DSC measurements revealed that small amount of low temperature eutectic reaction, L → Ag2In + β + γ, occurred at 112.9°C. This reaction was caused by the segregation of indium, which is a process that has a strong driving force. In the lap-shear testing, a crack propagated along the grain boundary of the solder, and failure showed an intergranular fracture. This failure was connected with the three-phase eutectic and coarse Ag2In. Thus, to improve the mechanical properties, segregation of indium should be reduced and coarsening of Ag2In should be prevented. Originality/value The reason for the unsatisfactory mechanical properties of Sn-20In-2.8Ag was revealed via microstructural observations and solidification analysis, and the way to solve this problem was found.

Physical and mechanical investigation for polyionic liquid/poly(vinyl alcohol) blends

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nehad N. Rozik ◽  
Emad Saad Shafik ◽  
Salwa L. Abd-El-Messieh
Keyword(s):  
Mechanical Properties ◽  
Vinyl Alcohol ◽  
Green Manufacturing ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Content Ratio ◽  
Mechanical Investigation ◽  
Manufacturing Techniques ◽  
Polyionic Liquid

Purpose This study aims to polymerize of 1-butyl-3-vinylimidazolium bromide (PIL). PIL was embedded into PVA with a different content ratio by casting method. This research also deals with the effect of adding PIL in different proportions to PVA on the electrical and mechanical properties properties in addition to the morphology of the prepared samples. Design/methodology/approach 1-Butyl-3-vinylimidazolium bromide was synthesized through quaternization and free radical polymerization. The resulting polymer was characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis and differential scanning calorimetry. In addition to the morphology of PVA, PVA/PIL was investigated by polarizing microscope. Also, the effect of PIL content on the electrical and mechanical properties was evaluated. Findings The findings of this study might lead to new applications for PVA and PILs in electrical and dielectrics. The mechanical results revealed that the tensile strength increased slightly with increasing polyionic liquid (PIL) content and decreased above 10% PIL. While the elongation at break increased significantly with increasing PIL content and begin to decrease above 10% PIL. Also, the electrical property of the poly(vinyl alcohol) (PVA)/PIL blends was improved because of the strong plasticizing effect of PIL. Also, the electrical conductivity of these polymer electrolytes is greatly increased. This indicates that the imidazolium-based PIL has an effective approach that leads to an increase in the conductivity of the polymer. The PILs/PVA design will not only enrich the chemical structure but also will contribute to green manufacturing techniques and a processing methodology that enables green membrane manufacture. Originality/value This study contributes to green manufacturing techniques and a processing methodology that enables “green” membrane manufacture.

Curing study and evaluation of epoxy resin with amine functional chloroaniline acetaldehyde condensate

2015 ◽  
Vol 44 (1) ◽  
pp. 19-25
Author(s):  
T. Maity ◽  
B.C. Samanta
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Epoxy Resin ◽  
Ph Value ◽  
Kinetic Studies ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Curing Reaction

Purpose – The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin. For this purpose, first AFCAC was synthesised, characterised and then curing reaction was carried out. Design/methodology/approach – Equimolecular mixture of AFCAC and DGEBA was subjected to curing reaction, and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction were also carried out from those DSC exotherms. The mechanical properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) of cured epoxy were also reported. Findings – DSC results reflected the effective first order curing reaction of AFCAC with epoxy resin. Mechanical properties reflected appreciable rigidity of AFCAC cured epoxy matrix and TGA showed that the cured epoxy networks were thermally stable up to around 297°C. Research limitations/implications – The curing agent AFCAC was synthesised by using chloroaniline and acetaldehyde in acid medium. There are some limitations for this procedure. The synthetic procedure is pH dependent. So reaction cannot be done at any pH value. The reaction must also be carried out at room temperature without any heating. To obtain low molecular weight curing agent, chloroaniline and acetaldehyde cannot be taken in equimolecular ratio because the equimolecular mixture of them produces high molecular weight condensate. This was shown in our previous publication. Some implications are also there. By changing amine and aldehyde other curing agents could be synthesised and the curing efficiency of those for epoxy resin could also be studied. Originality/value – Experimental results revealed the greater suitability of AFCAC as curing agent for DGEBA resin and novelty of AFCAC cured matrix in the field of protective coating, casting, adhesives, etc.

Detection threshold of chocolate graininess: machine vs human

2020 ◽  
Vol 122 (9) ◽  
pp. 2757-2767
Author(s):  
Sara De Pelsmaeker ◽  
Juliette S. Behra ◽  
Xavier Gellynck ◽  
Joachim J. Schouteten
Keyword(s):  
Particle Size ◽  
Detection Threshold ◽  
Solid Particles ◽  
Melting Behaviour ◽  
Human Beings ◽  
Particle Detection ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Dsc Measurements ◽  
Significant Difference

PurposeLiterature indicates that those solid chocolate particles cannot be detected by human beings that are smaller than a critical value between 25 and 35 µm. Chocolate containing particles larger than this range is thought to be perceived as grainy. However, there does not seem to be any publication which justifies this threshold. Hence, the main aim of this work is to determine if the threshold at which particles can be detected is indeed 30 µm.Design/methodology/approachThree dark chocolates containing solid particles of expected Dv,90 of 30 µm, 40 µm and 50 µm were produced. Particle Size Distribution (PSD) was determined using static light scattering while hardness and melting behaviour were characterised using a penetration test and Differential Scanning Calorimetry (DSC), respectively. Sensory analyses were performed with a trained panel (n = 9).FindingsPSD analyses indicated that the solid particle Dv,90 of the three chocolates were around 30 µm, 40 µm and 60 µm, respectively. DSC measurements showed no significant difference in melting behaviour between the chocolates. Hardness measurements showed that the “30 µm chocolate” was significantly harder than both the “40 µm chocolate” and the “60 µm chocolate”, while trained panellists found that the graininess of the 60 µm chocolate was significantly higher than that of the 40 µm and 30 µm chocolates.Practical implicationsThese results suggest that particle size detection threshold is higher than 40 µm. Chocolate manufacturers could thus increase the size of the biggest particles from 30 µm to 40 µm, leading to a decrease in production cost.Originality/valueThis is the first study to examine the particle detection limit of chocolate.

Fundamental investigation of part properties at accelerated beam speeds in the selective laser sintering process

2017 ◽  
Vol 23 (6) ◽  
pp. 1099-1106 ◽  
Author(s):  
Matthias Michael Lexow ◽  
Maximilian Drexler ◽  
Dietmar Drummer
Keyword(s):  
Mechanical Properties ◽  
Heating Rate ◽  
Energy Input ◽  
Selective Laser Sintering ◽  
Stable Process ◽  
Peak Height ◽  
Laser Sintering ◽  
Scanning Calorimetry ◽  
Content Type ◽  
The Core

Purpose Despite the recent progress in basic process understanding considering the selective laser sintering (SLS) of thermoplastics, several aspects of the mechanisms of the beam and powder interaction are not fully understood yet. Recent studies covered the correlation of mechanical properties and part density with the heating rate. The surface roughness of the test specimens was also considered but showed no distinct relation to the part mechanics. The purpose of this paper is to provide a new fundamental model for describing the decreasing mechanical properties with increasing beam speed. Design/methodology/approach While the dependence of mechanical properties with total energy input during exposure is well published, the correlation of the exposure speed with the degree of particle melt (DPM) is the subject of the present study. The DPM is accessible through differential scanning calorimetry measurements. Supporting the previously introduced method of the core-peak height, the interpretation via the core-peak area is proposed as a means to ascertain the melting behaviour for different processing conditions. Further support of the observations is given by x-ray computed tomography and microscopy which allows for a correlation with the respective porosity and inner structure of the parts. Findings The authors show a novel way of describing the decreasing mechanical properties with increasing speed of energy input by showing the dependence of the DPM on the heating rate during exposure. Practical implications The results offer an addition to the understanding considering the reliability and reproducibility of the SLS process. Originality/value The paper extends the existing models of the time-dependent material behaviour, which allows for the derivation of new efficient and stable process strategies.

Effect of post-treatment on the microstructure and mechanical properties of selective laser melted Ti6Al4V lattice structures

2020 ◽  
Vol 26 (9) ◽  
pp. 1569-1577
Author(s):  
Xina Huang ◽  
Lihui Lang ◽  
Shuili Gong ◽  
Mali Zhao
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Optical Microscope ◽  
Post Treatment ◽  
Lattice Structures ◽  
Electron Backscattered Diffraction ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Treatment Processes ◽  
Number Of Cycles

Purpose The purpose of this paper is to investigate the post-treatment processes on lattice structures of selective laser melting. Moreover, the effect of pressure during hot isostatic pressing (HIP) is determined. Design/methodology/approach Three post-treatment processes, annealing at 650°C, 920°C and HIP were adopted. The microstructure evolution and mechanical properties of selective lasering melted Ti6Al4V lattice structures after post-treatment were systematically investigated by optical microscope, scanning electron microscope, electron backscattered diffraction, differential scanning calorimetry and quasi-static mechanics tests. Findings The main findings in this paper are as below: first, the pores existing in the samples as-fabricated, annealed at 650°C and 920°C are disappeared after HIP. Second, the microstructure and compressive properties after HIP are similar to that after pure annealing at the same temperature. However, the HIPed sample had the highest number of cycles to failure. Third, the fracture mechanism of as-fabricated samples changes from mixed fracture to the micro-voids accumulation fracture after post-treatment processes. Originality/value HIP post-treatment can be replaced by annealing at the same temperature when the requirement for porosity and fatigue life is not very high.

Effects of inorganic components on the mechanical properties of inorganic-organic hybrids synthesized from metal alkoxides and polydimethylsiloxane

1999 ◽  
Vol 14 (5) ◽  
pp. 1720-1726 ◽  
Author(s):  
Noriko Yamada ◽  
Ikuko Yoshinaga ◽  
Shingo Katayama
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Network Structure ◽  
Molar Ratio ◽  
Metal Alkoxides ◽  
Inorganic Component ◽  
Scanning Calorimetry ◽  
Stress Strain ◽  
Dsc Measurements ◽  
Inorganic Components

Inorganic-organic hybrids (M–O–PDMS hybrids) have been synthesized from silanolterminated polydimethylsiloxane (PDMS) and inorganic sources of Al(O–sec–C4H9)3, Ti(OC2H5)4, and Ta(OC2H5)5. The molar ratio of M(OR)n/PDMS and the inorganic component derived from the different metal alkoxides were found to influence the structure and mechanical properties of the hybrids. Differential scanning calorimetry (DSC) measurements showed that the interaction between the inorganic component and PDMS increased in the order Al–O–PDMS < Ta–O–PDMS < Ti–O–PDMS hybrid. The stress-strain experiments revealed that the mechanical properties of the M–O–PDMS hybrids differed by the inorganic component, reflecting the network structure and strength of the interaction between the inorganic component and PDMS.

Observations during mechanical testing of Nitinol

2008 ◽  
Vol 222 (2) ◽  
pp. 97-105 ◽  
Author(s):  
J Eaton-Evans ◽  
J M Dulieu-Barton ◽  
E G Little ◽  
I A Brown
Keyword(s):  
Mechanical Properties ◽  
Mechanical Testing ◽  
Alloy Composition ◽  
Mechanical Deformation ◽  
Phase Transformation Temperature ◽  
Deformation History ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Characterization Study ◽  
Current Article

Superelastic and shape memory capabilities of Nitinol are strongly dependent on the alloy composition, its heat treatment, and mechanical deformation history. The current article presents a review of the behaviour of Nitinol and describes a characterization study conducted to determine the mechanical properties of the material, both by means of differential scanning calorimetry (DSC) and by mechanical testing at a range of temperatures. Values for key transformation temperatures are found using both techniques. It is concluded that mechanical deformation during sample preparation for DSC measurements may have led to material property modifications and hence erroneous phase transformation temperature values. It is shown that mechanical testing can provide a means of benchmarking DSC data.

Influence of lignin modification on the mechanical properties of lignin/PEO blends

2016 ◽  
Vol 7 (6) ◽  
pp. 762-772 ◽  
Author(s):  
Stavros C. Anagnou ◽  
Eleni G. Milioni ◽  
Costas S. Mpalias ◽  
Ioannis A. Kartsonakis ◽  
Elias P. Koumoulos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Tests ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Modified Lignin ◽  
Softwood Kraft Lignin

Purpose The purpose of this paper is to focus on the investigation of mechanical and thermal properties of lignin/poly (ethylene oxide) (PEO) blends, intended to be used as carbon fiber precursor. Design/methodology/approach Softwood kraft lignin was modified via esterification using phthalic anhydride and then blended with PEO. The final lignin/PEO ratios blends were (w/w) 20/80, 50/50 and 80/20 for both unmodified and modified lignin. The structural, thermal and mechanical properties of the blends were investigated by Fourier transform infrared, differential scanning calorimetry and tensile tests, respectively. Findings The results revealed that modified lignin/PEO blend (20/80) exhibited enhanced elongation. Originality/value The structural analysis as well as thermal and mechanical properties of the produced blends are clearly demonstrated.

Nanocrystal superlattices that exhibit improved order on heating: an example of inverse melting?

2015 ◽  
Vol 181 ◽  
pp. 181-192 ◽  
Author(s):  
Yixuan Yu ◽  
Avni Jain ◽  
Adrien Guillaussier ◽  
Vikas Reddy Voggu ◽  
Thomas M. Truskett ◽  
...  
Keyword(s):  
Structural Transition ◽  
Grazing Incidence ◽  
Melting Transition ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dsc Measurements ◽  
X Ray Scattering ◽  
Nanocrystal Superlattices ◽  
Melting And Solidification

Grazing incidence small angle X-ray scattering (GISAXS) measurements reveal that superlattices of 1.7 nm diameter, gold (Au) nanocrystals capped with octadecanethiol become significantly more ordered when heated to moderate temperatures (50–60 °C). This enhancement in order is reversible and the superlattice returns to its initially disordered structure when cooled back to room temperature. Disorder–order transition temperatures were estimated from the GISAXS data using the Hansen–Verlet criterion. Differential scanning calorimetry (DSC) measurements of the superlattices exhibited exotherms (associated with disordering during cooling) and endotherms (associated with ordering during heating) near the transition temperatures. The superlattice transition temperatures also correspond approximately to the melting and solidification points of octadecanethiol. Therefore, it appears that a change in capping ligand packing that occurs upon ligand melting underlies the structural transition of the superlattices. We liken the heat-induced ordering of the superlattices to an inverse melting transition.

scholarly journals Effect of Tantalum Addition on Properties of Cu–Zr–Based Thin Film Metallic Glasses (TFMGs)

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 515 ◽  
Author(s):  
Sofiane Achache ◽  
Frederic Sanchette
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Metallic Glasses ◽  
Xrd Analysis ◽  
Dynamic Mode ◽  
Dc Magnetron Sputtering ◽  
Scanning Calorimetry ◽  
Dsc Measurements

Cu–Zr–Ta ternary thin film metallic glasses (TFMGs) were deposited through the direct current (DC) magnetron sputtering of pure metallic targets in a dynamic mode. The effect of tantalum addition on the microstructure, mechanical properties, and thermal behavior of TFMGs were investigated. Nanoindentation measurements showed that an increase in tantalum content from 0 to 47 at % favored hardness and Young’s modulus, which rose from 5.8 to 11.23 Gpa and from 90 to 136 Gpa, respectively. XRD analysis and differential scanning calorimetry (DSC) measurements highlighted an improvement of thermal stability with the tantalum addition from 377 to 582 °C when the tantalum content increased from 0 to 31 at %.

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