scholarly journals Effect of Multiple Reflows on the Interfacial Reactions and Mechanical Properties of an Sn-0.5Cu-Al(Si) Solder and a Cu Substrate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2367
Author(s):  
Junhyuk Son ◽  
Dong-Yurl Yu ◽  
Yun-Chan Kim ◽  
Shin-Il Kim ◽  
Min-Su Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Heat ◽  
Interfacial Reactions ◽  
Future Application ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Automotive Electronic ◽  
Transmission Electron ◽  
Si Content ◽  
Lead Free Solders

In this study, the interfacial reactions and mechanical properties of solder joints after multiple reflows were observed to evaluate the applicability of the developed materials for high-temperature soldering for automotive electronic components. The microstructural changes and mechanical properties of Sn-Cu solders regarding Al(Si) addition and the number of reflows were investigated to determine their reliability under high heat and strong vibrations. Using differential scanning calorimetry, the melting points were measured to be approximately 227, 230, and 231 °C for the SC07 solder, SC-0.01Al(Si), and SC-0.03Al(Si), respectively. The cross-sectional analysis results showed that the total intermetallic compounds (IMCs) of the SC-0.03Al(Si) solder grew the least after the as-reflow, as well as after 10 reflows. Electron probe microanalysis and transmission electron microscopy revealed that the Al-Cu and Cu-Al-Sn IMCs were present inside the solders, and their amounts increased with increasing Al(Si) content. In addition, the Cu6Sn5 IMCs inside the solder became more finely distributed with increasing Al(Si) content. The Sn-0.5Cu-0.03Al(Si) solder exhibited the highest shear strength at the beginning and after 10 reflows, and ductile fracturing was observed in all three solders. This study will facilitate the future application of lead-free solders, such as an Sn-Cu-Al(Si) solder, in automotive electrical components.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.

Phase Stability and Mechanical Properties of Ti(Ni, Ru) Alloys

2002 ◽  
Vol 753 ◽  
Author(s):  
Masahiro Tsuji ◽  
Hideki Hosoda ◽  
Kenji Wakashima ◽  
Yoko Yamabe-Mitarai
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Phase Stability ◽  
Hot Forging ◽  
Tensile Tests ◽  
Lattice Parameter ◽  
Solid Solution Hardening ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Transmission Electron

ABSTRACTEffects of ruthenium (Ru) substitution on constituent phases, phase transformation temperatures and mechanical properties were investigated for Ti-Ni shape memory alloys. Ti50Ni50-XRuX alloys with Ru contents (X) from 0mol% (binary TiNi) to 50mol% (binary TiRu) were systematically prepared by Ar arc-melting followed by hot-forging at temperatures from 1173K to 1673K depending on chemical composition. Phase stability was assessed by DSC (differential scanning calorimetry), XRD (X-ray diffractometry) and TEM (transmission electron microscopy). Mechanical properties were investigated using hardness and tensile tests at room temperature. With increasing Ru content, it was found that the lattice parameter of B2 phase increases, the martensitic transformation temperature slightly decreases, and the melting temperature increases monotonously. Besides, R-phase appears for Ti-Ni alloys containing 3mol% and 20mol%Ru but no diffusionless phase transformation is seen in Ti-Ni alloy containing 5mol%Ru. Vickers hardness shows the maximum at an intermediate composition (HV1030 at 30mol%Ru); this suggests that large solid solution hardening is caused by Ru substitution for the Ni-sites in TiNi.

Effect of Co Addition on the Glass-Forming Ability and Mechanical Properties of Ti-Zr-Be-Cu-Co Bulk Amorphous Alloys

2012 ◽  
Vol 182-183 ◽  
pp. 203-207
Author(s):  
Zhong Yuan Suo ◽  
Yan Ling Song ◽  
Ke Qiang Qiu
Keyword(s):  
Mechanical Properties ◽  
Glassy Alloy ◽  
Glass Forming Ability ◽  
Yield Strain ◽  
Scanning Calorimetry ◽  
High Fracture ◽  
Glass Forming ◽  
Transmission Electron ◽  
Bulk Glassy Alloy ◽  
Co Addition

The effect of Co substitution for Be on the glass-forming ability and mechanical properties was investigated in Ti35Zr30Be27.5-xCu7.5Cox (x=0, 3.5, 7.5, 11.5 at.%) alloys by using X-ray diffractometry (XRD), differential scanning calorimetry (DSC), high-resolution transmission electron microscopy (HRTEM) and compression test. With the substitution of Co for Be, glass-forming ability (GFA) is significantly enhanced and fully amorphous rods with a diameter of up to 12 mm were produced in the alloy with 3.5 and 7.5 at.% Co. The Ti35Zr30Be24Cu7.5Co3.5 bulk glassy alloy exhibits good plasticity of 4% during compressive applied load at ambient temperature in conjunction with distinct yield strain of 2% and high fracture strength of 2196 MPa. The effect of the addition of Co on the structure and deformation behavior of the Ti35Zr30Be27.5-xCu7.5Cox (x=0, 3.5, 7.5, 11.5 at.%) alloys is discussed.

Effects of Thermal Treatment on the Morphology and Properties of CSM/Poly(Urethane-Isocyanurate) Composites Formed by SRIM Process

2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Treatment Time ◽  
Microphase Separation ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Scanning Electron

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.

Characterization of Structure and Mechanical Properties of MoSi2-SiC Nanolayer Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Crystallization Process ◽  
Mechanical Response ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Layer Structures ◽  
Amorphous Structures

AbstractA systematic study of the structure-mechanical properties relationship is reported for MoSi2-SiC nanolayer composites. Alternating layers of MoSi2 and SiC were synthesized by DCmagnetron and if-diode sputtering, respectively. Cross-sectional transmission electron microscopy was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures. Nanoindentation was employed to characterize the mechanical response as a function of the structural changes. As-sputtered material exhibits amorphous structures in both types of layers and has a hardness of 11GPa and a modulus of 217GPa. Subsequent heat treatment induces crystallization of MoSi2 to form the C40 structure at 500°C and SiC to form the a structure at 700°C. The crystallization process is directly responsible for the hardness and modulus increase in the multilayers. A hardness of 24GPa and a modulus of 340GPa can be achieved through crystallizing both MoSi2 and SiC layers. Annealing at 900°C for 2h causes the transformation of MoSi2 into the Cllb structure, as well as spheroidization of the layering to form a nanocrystalline equiaxed microstructure. A slight degradation in hardness but not in modulus is observed accompanying the layer break-down.

On the Microstructure of the Epoxy/Adherend Interphase

1995 ◽  
Vol 385 ◽  
Author(s):  
M. Libera ◽  
W. Zukas ◽  
S. Wentworth ◽  
A. Patel
Keyword(s):  
Dark Field ◽  
Interfacial Stress ◽  
Structural Variations ◽  
Anodized Aluminum ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Adequate Understanding ◽  
Annular Dark Field ◽  
Aluminum Surfaces

ABSTRACTIt is now recognized that there is a region at the epoxy/adherend interface known as the interphase whose chemistry and structure are different from those of bulk epoxy. There is, however, no adequate understanding of its microstructure. This paper describes differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) studies of the interphase between an aromatic amine cured epoxy and alumina/oxidized-aluminum surfaces. DSC results show dramatic differences in resin-cure behavior in the presence of particulate alumina. TEM results on microtomed cross-sectional specimens of anodized aluminum wire embedded in epoxy show regions of incomplete epoxy infiltration and interfacial stress. RuO4 staining combined with high-angle annular-dark-field STEM imaging indicates that there are structural variations within the bulk epoxy at lengths of ∼10–30nm. The magnitude of these fluctuations decreases in the near the adherend interface, and there is a simultaneous variation in the average epoxy structure. A plausible interpretation of these observations is that the interphase region suffers a variation in curing-agent concentration of unknown magnitude and there is a higher concentration of homopolymerized epoxy there relative to the bulk.

scholarly journals Effect of a Trace Addition of Sn on the Aging Behavior of Al–Mg–Si Alloy with a Different Mg/Si Ratio

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 913 ◽  
Author(s):  
Lehang Ma ◽  
Jianguo Tang ◽  
Wenbin Tu ◽  
Lingying Ye ◽  
Haichun Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Number Density ◽  
Precipitation Behavior ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Positive Effect ◽  
Room Temperature Tensile Test

In this paper, the effect of trace Sn on the precipitation behavior and mechanical properties of Al–Mg–Si alloys with different Mg/Si ratios aged at 180 °C was investigated using hardness measurements, a room-temperature tensile test, transmission electron microscopy and differential scanning calorimetry. The results shown that Sn reduces the precipitation activation energy, increases the number density of β″ precipitates, and then increased the aging hardenability and mechanical properties of the Al–Mg–Si alloy. However, the positive effect of Sn on the mechanical properties of the Al–Mg–Si alloy drops with the decrease of the Mg/Si ratio of the alloy.

Transmission electron microscopy studies of interfacial reactions and void formation in lead-free solders with minor elements

2010 ◽  
Vol 25 (7) ◽  
pp. 1304-1311 ◽  
Author(s):  
Y.T. Chin ◽  
P.K. Lam ◽  
H.K. Yow ◽  
T.Y. Tou
Keyword(s):  
Surface Finish ◽  
Intermetallic Layer ◽  
Void Formation ◽  
Electroless Nickel ◽  
Interfacial Reactions ◽  
Lead Free ◽  
Form Complex ◽  
Minor Elements ◽  
Transmission Electron ◽  
Lead Free Solders

Electroless nickel (Ni–P) is a common surface finish used in the ball grid array (BGA) package and interfacial reactions between its surface finish and lead-free solders can form complex intermetallic compound (IMC) layers. The presence of minor elements in lead-free solders either intentionally added or due to impurity contamination during solder manufacturing, can affect the solder-joint performance. In this work, interfacial reactions between Ni–P surface finish and the Sn–Ag–Cu solders were modified by varying Ag and Cu contents and also by adding a small amount of minor elements such as phosphorus (P), indium (In), and germanium (Ge). A transmission electron microscope was used to determine the intermetallic layer phases, compositions, crystal structures, and void defects. Varying the solder alloy elements led to the modulation of voids formation.

Structural Transitions in Titanium/Amorphous-Silicon Multilayers

1989 ◽  
Vol 163 ◽  
Author(s):  
E. Ma ◽  
L.A. Clevenger ◽  
C.V. Thompson ◽  
R.R. DeAvillez ◽  
K.N. Tu
Keyword(s):  
Thin Films ◽  
Exothermic Reaction ◽  
Heat Of Formation ◽  
Structural Transitions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Calorimetric Analysis ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

We report a quantitative investigation of silicidation in Ti/amorphous-Si thin-films using Differential Scanning Calorimetry (DSC), thin-film X-ray diffraction and Cross-sectional Transmission Electron Microscopy (XTEM). Multilayered thin films were used to facilitate calorimetric observation of the heat released or absorbed at many reacting interfaces. It is shown that calorimetric analysis, combined with structural analysis using X-ray diffraction and XTEM, is effective in providing both kinetic and thermodynamic information about interdiffusion reactions in thin films. The present paper describes experimental results for multilayers with an atomic concentration ratio of 1 Ti to 2 Si and modulation periods ranging from 10 to 60 nm. A thin amorphous titanium suicide layer was found to exist between the as-deposited Ti and a-Si layers. Heating the multilayer film caused the amorphous Ti-silicide to grow over a broad temperature range by an exothermic reaction. An endothermic relaxation occurs during the late stage of amorphous suicide growth. Heating to temperatures over 800K causes C49-TiSi2 to form at the a-si1icide/a-Si interface. Temperatures at which all the above structural transitions occur vary with modulation period. Analysis of the DSC data indicates an activation energy of 3.1 eV for the formation of C49-TiSio, which is attributed to both the nucleation and the early growth of the suicide. The heat of formation for C49-TiSi2 from a reaction of a-silicide and a-Si was found to be -30±5KJ/mol. Nucleation appears to be the controlling step in C49-TiSi2 formation.

Biocompatible Phosphorus-based Monomers for Radical Polymerization

2009 ◽  
Vol 1235 ◽  
Author(s):  
Claudia Dworak ◽  
Christian Heller ◽  
Franz Varga ◽  
Robert Liska
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Radical Polymerization ◽  
Hydrolytic Degradation ◽  
Future Application ◽  
Vinyl Esters ◽  
Degradation Behavior ◽  
Scanning Calorimetry ◽  
Phosphorus Containing

AbstractNovel biocompatible and biodegradable monomers based on phosphorus-containing vinyl esters and vinyl carbamates for radical photopolymerization were prepared. By photo-Differential Scanning Calorimetry (photo-DSC) the reactivity of the mono-, di- and trifunctional monomers was investigated. Furthermore, their cytotoxicity, mechanical properties and hydrolytic degradation behavior were evaluated, aiming at a future application of our compounds in the biomedical area.

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