scholarly journals Interfacial Reaction and Microstructure Evolution of Sn-9Zn/Ni(Cu) Solder Joints

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 604 ◽  
Author(s):  
Xuewei Zhu ◽  
Jian Peng ◽  
Xiaofeng Wei ◽  
Pengpeng Yan ◽  
Fu Wang
Keyword(s):  
Solid Solution ◽  
Interfacial Reaction ◽  
Layered Structure ◽  
Mechanical Performance ◽  
Reaction Products ◽  
Simple Metal ◽  
Fine Grained ◽  
Cu Content ◽  
Study Results ◽  
Free Solder

Sn-9Zn solder is a promising Pb-free solder, but it tends to form bulky intermetallic compounds (IMC) grains at the interface when soldered with common simple metal Cu or Ni substrates. Interfacial reaction between Sn-9Zn solder and Ni(Cu) solid solution substrates at 250 °C and 350 °C were systematically probed in this study. Results showed that when soldered at 250 °C, a Ni5Zn21 layer is formed at Sn-Zn/Ni-20Cu and Sn-Zn/Ni-40Cu joints; and Ni2Sn2Zn + Cu5Zn8 and Cu5Zn8 phases are formed in Sn-Zn/Ni-60Cu and Sn-Zn/Ni-80Cu joints, respectively. Fine-grained IMCs formed at the interface are formed even when the soldered time is prolonged to 16 h. This result indicates that Ni(Cu) solid solution substrates inhibit the rapid growth of IMC at the Sn-Zn/Ni-Cu interface. Ni(Cu) solid solution substrate can also provide various combinations of reaction products at the Sn-Zn/Ni-Cu joints. The Ni5Zn21 transfers to Ni2Sn2Zn + Cu5Zn8 phases when the Cu content increased to 60%, and a bi-layered structure Ni2Sn2Zn + Cu5Zn8 IMCs was formed in Sn-Zn/Ni(Cu) joints at 350 °C regardless of the Cu content in Ni(Cu) substrate (20–80%). These results would provide an effective support in designing Sn-Zn soldering system with optimized IMC layer to improve mechanical performance.

Interfacial reactions in the Sn–9Zn–(xCu)/Cu and Sn–9Zn–(xCu)/Ni couples

2006 ◽  
Vol 21 (7) ◽  
pp. 1849-1856 ◽  
Author(s):  
Chin-yi Chou ◽  
Sinn-wen Chen ◽  
Yee-shyi Chang
Keyword(s):  
Reaction Time ◽  
Melting Point ◽  
Oxidation Resistance ◽  
Interfacial Reaction ◽  
Interfacial Reactions ◽  
Reaction Products ◽  
Phase Layer ◽  
Cu Content ◽  
Wetting Properties ◽  
Interfacial Reaction Product

Sn–Zn-based alloys are promising low melting-point Pb-free solders, and it has been reported that their wetting properties and oxidation resistance can be improved with the addition of Cu. The interfacial reactions in the Sn–9 wt% Zn–xCu/Cu couples at 250 °C and Sn–9 wt% Zn–xCu/Ni at 280 °C were examined in this study. A thick γ–Cu5Zn8 phase layer and a very thin β′–CuZn phase layer were formed in both the Sn–9 wt% Zn/Cu and the Sn–9 wt% Zn–1 wt% Cu/Cu couples. The γ–Ni5Zn21 phase layer was formed in both the Sn–9 wt% Zn/Ni and Sn–9 wt% Zn–1 wt% Cu/Ni couples. With longer reaction time, the δ–Ni3Sn4 phase were formed in the Sn–9 wt% Zn/Ni couple as well. In both the Cu and Ni couples, the Zn-containing γ phases were uniform and planar and were the dominant reaction products. However, when the Cu content of the Sn–9 wt% Zn–xCu solders was 10 wt%, the interfacial reaction product becomes the η–Cu6Sn5 phase in both the Cu and Ni couples.

scholarly journals Potential-pH diagrams considering complex oxide solution phases for understanding aqueous corrosion of multi-principal element alloys

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Kang Wang ◽  
Junsoo Han ◽  
Angela Yu Gerard ◽  
John R. Scully ◽  
Bi-Cheng Zhou
Keyword(s):  
Solid Solution ◽  
Free Energy ◽  
Graphical Representation ◽  
Equilibrium Composition ◽  
Complex Oxide ◽  
Oxidation Products ◽  
Reaction Products ◽  
Aqueous Corrosion ◽  
Principal Element ◽  
Diagram Method

AbstractThe potential-pH diagram, a graphical representation of the thermodynamically predominant reaction products in aqueous corrosion, is originally proposed for the corrosion of pure metals. The original approach only leads to stoichiometric oxides and hydroxides as the oxidation products. However, numerous experiments show that non-stoichiometric oxide scales are prevalent in the aqueous corrosion of alloys. In the present study, a room temperature potential-pH diagram considering oxide solid solutions, as a generalization of the traditional potential-pH diagram with stoichiometric oxides, is constructed for an FCC single-phase multi-principal element alloy (MPEA) based on the CALculation of PHAse Diagram method. The predominant reaction products, the ions in aqueous solution, and the cation distribution in oxides are predicted. The oxide solid solution is stabilized by the mixing free energy (or mixing entropy) and the stabilizing effect becomes more significant as the temperature increases. Consequently, solid solution oxides are stable in large regions of the potential-pH diagram and the mixing free energy mostly affects the equilibrium composition of the stable oxides, while the shape of stable regions for oxides is mostly determined by the structure of the stable oxides. Agreements are found for Ni2+, Fe2+, and Mn2+ between the atomic emission spectroelectrochemistry measurements and thermodynamic calculations, while deviations exist for Cr3+ and Co2+ possibly due to surface complexation with species such as Cl− and the oxide dissolution. By incorporating the solution models of oxides, the current work presents a general and more accurate way to analyze the reaction products during aqueous corrosion of MPEAs.

Suppression of vigorous liquid Sn/Te reactions by Sn–Cu solder alloys

2008 ◽  
Vol 23 (12) ◽  
pp. 3303-3308 ◽  
Author(s):  
Chien-Neng Liao ◽  
Ching-Hua Lee
Keyword(s):  
Reaction Time ◽  
Layered Structure ◽  
Controlled Growth ◽  
Square Root ◽  
Solder Alloys ◽  
Cu Content ◽  
Cu Alloys ◽  
Diffusion Controlled ◽  
Morphology Changes

Reactions of molten Sn–xCu (x = 0.05 to 1.0) alloys with Te substrate at 250 °C were investigated. A dosage of 0.1 wt% Cu in Sn is found to be effective in suppressing the vigorous Sn/Te reaction by forming a thin CuTe at the solder/Te interface. The CuTe morphology changes from irregular clusters into a layered structure with increasing Cu content in Sn. With the same reaction time, the CuTe thickness increases proportionally to the square root of Cu content in Sn–Cu alloys, suggesting a diffusion-controlled growth for CuTe.

scholarly journals The Effect of Ni Addition onto a Cu-Based Ternary Support on the H2 Production over Glycerol Steam Reforming Reaction

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 931 ◽  
Author(s):  
Kyriaki Polychronopoulou ◽  
Nikolaos Charisiou ◽  
Kyriakos Papageridis ◽  
Victor Sebastian ◽  
Steven Hinder ◽  
...  
Keyword(s):  
Sol Gel ◽  
Strong Acid ◽  
H2 Production ◽  
Impregnation Method ◽  
Reaction Products ◽  
Cu Content ◽  
Ni Addition ◽  
Support Matrix ◽  
Temperature Programmed ◽  
H2 Yield

In the present study, Ni/Ce-Sm-xCu (x = 5, 7, 10 at.%) catalysts were prepared using microwave radiation coupled with sol-gel and followed by wetness impregnation method for the Ni incorporation. Highly dispersed nanocrystallites of CuO and NiO on the Ce-Sm-Cu support were found. Increase of Cu content seems to facilitate the reducibility of the catalyst according to the H2 temperature-programmed reduction (H2-TPR). All the catalysts had a variety of weak, medium and strong acid/basic sites that regulate the reaction products. All the catalysts had very high XC3H8O3 for the entire temperature (400–750 °C) range; from ≈84% at 400 °C to ≈94% at 750 °C. Ni/Ce-Sm-10Cu catalyst showed the lowest XC3H8O3-gas implying the Cu content has a detrimental effect on performance, especially between 450–650 °C. In terms of H2 selectivity (SH2) and H2 yield (YH2), both appeared to vary in the following order: Ni/Ce-Sm-10Cu > Ni/Ce-Sm-7Cu > Ni/Ce-Sm-5Cu, demonstrating the high impact of Cu content. Following stability tests, all the catalysts accumulated high amounts of carbon, following the order Ni/Ce-Sm-5Cu < Ni/Ce-Sm-7Cu < Ni/Ce-Sm-10Cu (52, 65 and 79 wt.%, respectively) based on the thermogravimetric analysis (TGA) studies. Raman studies showed that the incorporation of Cu in the support matrix controls the extent of carbon graphitization deposited during the reaction at hand.

Effects of hydrogen on the microstructure and microchemistry of Ti3Al – Nb intermetallics at high temperatures and high pressures

1996 ◽  
Vol 11 (9) ◽  
pp. 2186-2197 ◽  
Author(s):  
H. Z. Xiao ◽  
I. M. Robertson ◽  
H. K. Birnbaum
Keyword(s):  
Solid Solution ◽  
High Temperatures ◽  
High Pressures ◽  
Chemical Potential ◽  
Substitutional Solid Solution ◽  
Hydrogen Gas ◽  
Solid Solution Phase ◽  
Face Centered Cubic ◽  
Fine Grained ◽  
Surrounding Matrix

The microstructural and microchemical changes produced in a Ti–25Al–10Nb–3V–1Mo alloy (at. %) by charging at high temperatures in high pressures of hydrogen gas have been studied using transmission electron microscopy (TEM) and x-ray methods. Hydrides incorporating all of the substitutional solutes that formed during charging have a face-centered cubic (fcc) structure and exhibit either a plate or fine-grained morphology. With increasing hydrogen content, the size of the hydrides decreases and their microchemistry changes as they approach the stable binary hydride, TiH2. Rejection of substitutional solute elements from the hydride produces changes in the microchemistry, and consequently in the crystal structure, of the surrounding matrix. In alloys containing 50 at. % H, this solute redistribution results in the formation of an orthohombic substitutional solid solution phase containing increased levels of Nb. The driving force of this redistribution of solutes is the reduction in the chemical potential of the system as the amount of the most stable hydride, TiH2, forms. The hydrides reverted to a solid solution on annealing in vacuum at 1073 K, and the original microchemistry of the alloy was restored. Reversion from the hydride structure to the original α2 ordered DO19 structure proceeds via a disordered HCP phase.

scholarly journals Reaction products of Sm2Zr2O7 with calcium-magnesium-aluminum-silicate (CMAS) and their evolution

2021 ◽  
Author(s):  
Yinghua Wang ◽  
Zhuang Ma ◽  
Ling Liu ◽  
Yanbo Liu
Keyword(s):  
Solid Solution ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Reaction Products ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Composition Segregation ◽  
Calcium Magnesium ◽  
New Generation ◽  
Sand Dust

AbstractDuring flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (such as Sm2Zr2O7) have good CMAS resistance properties. The reaction products of Sm2Zr2O7 and CMAS and their subsequent changes were studied by the reaction of Sm2Zr2O7 and excess CMAS at 1350 °C. After 1 h of reaction, Sm2Zr2O7 powders were not completely corroded. The reaction products were Sm-apatite and c-ZrO2 solid solution. After 4 h of reaction, all Sm2Zr2O7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO2 solid solution remained.

scholarly journals Stream plant chemistry as indicator of acid sulphate soils in Sweden

2008 ◽  
Vol 14 (1) ◽  
pp. 83 ◽  
Author(s):  
K. LAX
Keyword(s):  
Surface Waters ◽  
Stream Water ◽  
Low Ph ◽  
Fontinalis Antipyretica ◽  
Acid Sulphate ◽  
Fine Grained ◽  
Acid Sulphate Soils ◽  
Trace Element Chemistry ◽  
Study Results ◽  
The Impact

Results from the biogeochemical mapping (roots of aquatic plants and Fontinalis antipyretica) conducted by the Geological Survey of Sweden (SGU) reflects the metal load of surface waters draining acid sulphate (AS) soils in Sweden. In this study, results from the biogeochemical, soil geochemical and Quaternary mapping programmes at SGU were used to investigate the impact of fine-grained deposits hosting AS soils on stream water trace element chemistry in two separate areas. In the area around Lake Mälaren, postglacial sediments contain the highest levels of most trace elements studied. Owing to the low pH of AS soils and subsequent leaching, levels of nickel (Ni), cobalt (Co), copper (Cu), sulphur (S), yttrium (Y), uranium (U), tungsten (W), and molybdenum (Mo) were significantly elevated in aquatic roots. Levels were lower in the Skellefteå area, which may be explained by lower concentrations in source deposits. Concentrations of arsenic (As) and lead (Pb) were normal or impoverished in biogeochemical samples from postglacial, finegrained sediment areas. Maps based on ratios (Ni:Pb or Y:Pb) in biogeochemical samples can, together with results from Quaternary mapping, be used to predict areas with AS soils in Sweden.;

Evidence for hibbingite–kempite solid solution

1998 ◽  
Vol 62 (2) ◽  
pp. 251-255 ◽  
Author(s):  
Bernhardt Saini-Eidukat ◽  
Nikolai S. Rudashevsky ◽  
Alexander G. Polozov
Keyword(s):  
Solid Solution ◽  
Siberian Platform ◽  
Lower Paleozoic ◽  
Fine Grained ◽  
Platinum Group Minerals ◽  
Mineral Assemblages ◽  
Native Silver ◽  
Chalcopyrite Ore ◽  
Silver Grains ◽  
New Occurrences

AbstractNew occurrences of hibbingite, γ-Fe2(OH)3Cl, have been found associated with platinum-group minerals in the Noril'sk Complex, and with the Korshunovskoye iron ores of the southern Siberian platform. The Norils'k grains, which are up to 0. 6 mm in diameter, are associated with the platinumgroup minerals froodite, cabriite, urvantsevite and with native silver in massive pentlandite–cubanite– chalcopyrite ore. The Korshunovskoye iron ore sample in which hibbingite was found is composed of fine-grained magnetite ore associated with halite. Hibbingite, hematite and silver grains are found in cavities in halite; the reddish-brown hibbingite grains usually occur as encrustations in the cavities. The size of hibbingite and hematite grains is up to 100 µm.Hibbingite from the Noril'sk Complex contains a significant kempite (Mn2(OH)3Cl) component; in some cases it contains over 50 mol. % Mn. These data suggest that at least a partial solid solution series exists between hibbingite and kempite. All known occurrences of hibbingite represent paragenetically late mineral assemblages. In the case of the Korshunovskoye deposits, the occurrences are associated with highly concentrated hydrothermal brines derived from the Lower Paleozoic saline sediments of the Siberian Platform cover.

scholarly journals Superplasticity and Newtonian-viscous flow in fine-grained class I solid solution alloys.

1991 ◽  
Vol 31 (1) ◽  
pp. 76-85 ◽  
Author(s):  
H. Fukuyo ◽  
H. C. Tsai ◽  
T. Oyama ◽  
O. D. Sherby
Keyword(s):  
Solid Solution ◽  
Viscous Flow ◽  
Class I ◽  
Fine Grained
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