Formation of Primary Intermetallic Compounds in Sn-Ag-Cu Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 1397-1399 ◽  
Author(s):  
Yoshiko Takamatsu ◽  
Hisao Esaka ◽  
Kei Shinozuka
Keyword(s):  
Liquid Phase ◽  
Intermetallic Compounds ◽  
Ternary Eutectic ◽  
Equilibrium Phase ◽  
Solidification Process ◽  
Equilibrium Phase Diagram ◽  
Primary Phase ◽  
Cu Alloys ◽  
Binary Eutectic ◽  
Free Solder

Sn-Ag-Cu alloys are considered one of the most favorable lead-free solder systems. In slowly-cooled eutectic Sn-Ag-Cu alloys, sometimes large primary Ag3Sn or Cu6Sn5 intermetallic compounds (IMCs) form. These IMCs may affect the mechanical properties of solders. However, explanations for the formation of these IMCs are still not clear. This study deals with interrupted tests in order to clarify the nucleation of IMCs in the liquid phase. In this study, Sn-4.41Ag-0.63Cu and Sn-3.30Ag-1.47Cu alloys were prepared. According to the thermodynamic calculation, Pandat, the equilibrium solidification paths are described as follows: Sn-4.41Ag-0.63Cu :L → primary Ag3Sn → binary eutectic (Ag3Sn +Sn) → ternary eutectic; Sn-3.30Ag-1.47Cu :L → primary Cu6Sn5 → binary eutectic (Cu6Sn5 + Sn)→ ternary eutectic. The actual solidification process was different from the estimation from the equilibrium phase diagram. In the case of Sn-4.41Ag-0.63Cu, only Ag3Sn grew as a primary phase in the liquid, while in the case of Sn-3.30Ag-1.47Cu, not only primary Cu6Sn5 but also pseudo-primary Ag3Sn grew in the liquid. Ag3Sn may nucleate easily in the liquid phase, but Cu6Sn5 would not nucleate in the liquid.

Microstructure and Mechanical Properties of Sintered Ti-Cu Alloys

2010 ◽  
Vol 93-94 ◽  
pp. 99-104 ◽  
Author(s):  
P. Pripanapong ◽  
Luangvaranunt Tachai
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Exothermic Reaction ◽  
Equilibrium Phase ◽  
Pure Titanium ◽  
Equilibrium Phase Diagram ◽  
Cu Alloys ◽  
Effect Of Copper ◽  
Sintered Alloys ◽  
Dental Applications

The use of titanium for medical and dental applications is on the rise because of their excellent biocompatibility. However, some properties of pure titanium are not sufficient. Alloying with copper can improve mechanical properties needed for dental use. A recent research on Ti-Cu cast alloy indicated that ductility decreased with increasing copper concentration, but addition of copper improved grindability and wear resistance, with lower corrosion resistance. The objective of this research is to study sintering of Ti-Cu alloys; their microstructure and hardness, and the effect of copper content to their sintered density. Ti-Cu alloys were produced via powder metallurgy. Titanium powder was mixed with copper powder with chemical composition of 2, 4, 7 and 10 wt%. Lubricant was added in alloy powder with 0.5% of total weight, followed by cold compaction under 254 MPa pressure. Debinding and sintering was carried out at 400oC for 0.5 hr and 1000oC for 1 hr respectively in argon atmosphere. Condition with highest density was found in 10wt%Cu composition; having highest hardness of 317 Hv. Differential thermal analysis of Ti-15Cu under N2 atmosphere showed exothermic reaction at 1078oC. Phase formation of the sintered alloys followed the Ti-Cu equilibrium phase diagram.

Effect of Al-5Ti-1B Grain Refiner Addition on the Formation of Intermetallic Compounds in Al-Mg-Si-Mn-Fe Alloys

2015 ◽  
Vol 828-829 ◽  
pp. 53-57 ◽  
Author(s):  
Zhong Ping Que ◽  
Yun Wang ◽  
Y.P. Zhou ◽  
L. Liu ◽  
Z. Fan
Keyword(s):  
Intermetallic Compounds ◽  
Heterogeneous Nucleation ◽  
Ternary Eutectic ◽  
Experimental Results ◽  
Solidification Microstructure ◽  
Chinese Script ◽  
Secondary Branch ◽  
Grain Refiner ◽  
Binary Eutectic ◽  
Fe Alloys

The effect of Al-5Ti-1B grain refiner addition on solidification microstructure, especially the formation of the binary eutectic (Al)+Al15(Fe,Mn)3Si2was investigated in Al-5Mg-2Si-0.7Mn-1.1Fe (wt.%) alloy. The experimental results showed that the solidification microstructure were consisted of primary α-Al phase, inter dendritic binary eutectic (Al)+Al15(Fe,Mn)3Si2, and ternary eutectic (Al+Mg2Si+Al15(Fe,Mn)3Si2). The heterogeneous nucleation of the primary (Al) phase in the alloys was greatly enhanced by the Al-5Ti-1B grain refiner, refining the (Al) grains significantly. The subsequent binary eutectic was nucleated on these refined (Al) phase. Consequently, the size of Al15(Fe,Mn)3Si2phase with a Chinese script morphology in the binary eutectic was greatly refined, without much change in the secondary branch spacing.

scholarly journals Selection of Dedicated As-Cast Microstructures in Zn-Al-Cu Alloys for Bearing Applications Supported by Phase-Field Simulations

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1659
Author(s):  
Steffen Gimmler ◽  
Markus Apel ◽  
Andreas Bührig-Polaczek
Keyword(s):  
Phase Field ◽  
Ternary Eutectic ◽  
Phase Field Model ◽  
Eutectic Point ◽  
Casting Process ◽  
Primary Phase ◽  
Spatially Resolved ◽  
Cu Alloys ◽  
Mold Casting ◽  
Ε Phase

Solidification and phase formation of Zn-rich Zn-Al-Cu alloys with different Al and Cu contents were investigated. The investigations comprise alloy compositions with either hcp η, fcc α or hcp ε as the primary phase, as well as a composition close to the ternary eutectic point. Test samples were produced in a mold casting process and their microstructures were investigated by scanning electron microscopy. Experimental microstructures are compared with the results from spatially resolved microstructure simulations using a phase-field model. In particular, the dependency between the aluminum and copper contents and the phase fractions of the η, α and ε phases were analyzed. In addition, hardness tests for the samples prove a direct correlation between the α- and ε-phase fractions with the macroscopic hardness of the alloys. A simple model, based on the phase fractions and the properties of the single phases, is suggested for the computation of hardness from the simulation results in order to select appropriate alloy compositions for bearing applications.

Chemical analysis in YBa2Cu3O7−x melt-textured samples

1997 ◽  
Vol 12 (2) ◽  
pp. 338-346 ◽  
Author(s):  
F. J. Gotor ◽  
J. Ayache ◽  
N. Pellerin ◽  
P. Odier
Keyword(s):  
Liquid Phase ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Exact Nature ◽  
Chemical Homogeneity ◽  
X Ray ◽  
Accurate Knowledge ◽  
Sample Composition ◽  
Control Chemical ◽  
Rich Liquid

A melt-textured process that involves the peritectic reaction Y2BaCuO5 + liquid → YBa2Cu3O7−x is the best method to develop bulk YBa2Cu3O7−x superconductors with improved transport and magnetic properties. Up to this point, information regarding cationic stoichiometry in textured samples is rather lacking in the literature. In this work, wavelength dispersive analysis (WDS) at a microscopic level and energy dispersive x-ray analysis (EDX) at a nanoscopic level were used to characterize the chemical composition of YBa2Cu3O7−x textured samples. The melt-textured process generally modifies the sample stoichiometry. Thus, a textured sample composition cannot be directly obtained even from an accurate knowledge of the starting composition. We have shown that WDS can be used to determine the overall composition and therefore the Y2BaCuO5 content in these samples. It is also a powerful method to control chemical homogeneity and to investigate chemical modifications occurring during processing, especially those resulting from interaction between melt and substrate. The exact nature of YBa2Cu3O7−x nucleation and crystallization still presents many unsolved questions. Nanoanalysis allowed us to study Y2BaCuO5 dissolution in the peritectic liquid, and we have confirmed that it takes place exclusively by removing yttrium from Y2BaCuO5 particles. We have also shown the existence of an yttrium-rich liquid phase, i.e., with a higher yttrium concentration that can be deduced from the equilibrium phase diagram. A liquid phase having a composition close to that of YBa2Cu3O7−x can be inferred from this work. This suggests that YBa2Cu3O7−x nucleation and crystallization take place homogeneously from this liquid.

Laser Cladding of an In Situ Synthesized TiB and TiC Reinforced Titanium Matrix Composite Coating on Ti6Al4V

2010 ◽  
Vol 97-101 ◽  
pp. 3861-3865
Author(s):  
Jun Li ◽  
Zhi Shui Yu ◽  
Hui Ping Wang
Keyword(s):  
Composite Coating ◽  
Matrix Composite ◽  
Laser Cladding ◽  
Ternary Eutectic ◽  
Solidification Process ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Martensitic Microstructure ◽  
Binary Eutectic

A titanium matrix composite coating reinforced by in situ synthesized TiB and TiC was deposited on Ti6Al4V by laser cladding. Microstructural analyses were made by means of X-ray Diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Electron Probe Micro-Analysis (EPMA). The solidification process was also discussed in detail. The results show that the coating is composed of -Ti cellular dendrites and a eutectic in which a large number of needle-shaped TiB whiskers and a few equiaxial TiC particles are embedded. A thin dilution zone with a thickness of 50 m is observed at the interface, and consists of a few TiB and TiC and a large number of lamella grains in which a thin needle-shaped martensitic microstructure is exist. The solidification process could be divided into four stages: nucleation and growth of primary -Ti phase, precipitation of a binary eutectic -Ti+TiB, precipitation of a ternary eutectic -Ti+TiB+TiC and solid transformation from -Ti to -Ti.

Modeling of the Divorced Eutectic Solidification of Spheroidal Graphite Cast Iron

2010 ◽  
Vol 457 ◽  
pp. 324-329 ◽  
Author(s):  
Hong Lee Zhao ◽  
Ming Fang Zhu ◽  
Doru Michael Ştefănescu
Keyword(s):  
Cast Iron ◽  
Microstructure Evolution ◽  
Equilibrium Phase ◽  
Carbon Diffusion ◽  
Equilibrium Phase Diagram ◽  
Primary Phase ◽  
Eutectic Solidification ◽  
Spheroidal Graphite ◽  
Primary Austenite ◽  
Sg Iron

The solidification of the austenite-spheroidal graphite (SG) eutectic is one of the most complex and therefore most difficult liquid-to-solid transformations to describe through computational modeling. This is because the iron-carbon equilibrium phase diagram is an asymmetric diagram that predicts that at relatively low solidification velocities it is possible to produce primary austenite in a casting of eutectic composition. In addition, the two phases of the eutectic solidify as a divorced eutectic, with only the austenite being in contact with the eutectic liquid. The paper proposes a computational model for the eutectic solidification of SG iron with visualization of the microstructure evolution using a cellular automaton technique. The model is an extension of the earlier Zhu-Stefanescu model for primary phase solidification and includes the growth of primary SG in the liquid, of primary austenite and of the austenite-graphite eutectic controlled by carbon diffusion through the solid austenite shell. The model outputs realistic images of the microstructure evolution from the beginning to the end of eutectic solidification of SG cast iron.

Magnetic Percolation in New Crystalline FCC Fe-Cu Alloys

1986 ◽  
Vol 80 ◽  
Author(s):  
C. L. Chien ◽  
S. H. Liou ◽  
Gang Xiao ◽  
M. A. Gatzke
Keyword(s):  
Equilibrium Phase ◽  
Magnetic Ordering ◽  
Equilibrium Phase Diagram ◽  
Squid Magnetometry ◽  
Cu Alloys ◽  
Fcc Lattice ◽  
Percolation Phenomena ◽  
Quenching Method ◽  
Vapor Quenching ◽  
Dilute Limit

AbstractMagnetic percolation has rarely been realized in Fe-based binary alloys either because Fe does not retain its moment in the dilute limit or because the solubility is too low. By using a vapor quenching method, which in our case is highrate sputtering, we have succeeded in making new metastable crystalline alloys of fcc FexCu1−x which do not appear in the equilibrium phase diagram. These alloys spanning the percolation threshold allow magnetic percolation phenomena on an fcc lattice to be observed by SQUID magnetometry and Mössbauer spectroscopy. Above xc, the magnetic ordering temperature varies as (x−xc)γ with xc = 0.185 and γ = 0.63. Below xc, spin glass ordering has been observed.

scholarly journals Influence of copper content on microstructure development of AlSi9Cu3 alloy

2014 ◽  
Vol 50 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Zovko Brodarac ◽  
N. Dolic ◽  
F. Unkic
Keyword(s):  
Copper Content ◽  
Ternary Eutectic ◽  
Equilibrium Phase ◽  
Intermetallic Phase ◽  
Equilibrium Phase Diagram ◽  
Metallographic Analysis ◽  
Microstructure Development ◽  
Microstructural Investigation ◽  
Solidification Sequence

Microstructure development and possible interaction of present elements have been determined in charge material of EN AlSi9Cu3 quality. Literature review enables prediction of solidification sequence. Modelling of equilibrium phase diagram for examined chemical composition has been performed, which enables determination of equilibrium solidification sequence. Microstructural investigation indicated distribution and morphology of particular phase. Metallographic analysis tools enable exact determination of microstructural constituents: matrix ?Al, eutectic ?Al+?Si, iron base intermetallic phase - Al5FeSi, Alx(Fe,Mn)yCuuSiw and/or Alx(Fe,Mn)yMgzCuuSiw and copper base phases in ternary eutectic morphology Al-Al2Cu-Si and in complex intermetallic ramified morphology Alx(Fe,Mn)yMgzSiuCuw. Microstructure development examination reveals potential differences due to copper content which is prerequisite for high values of final mechanical, physical and technological properties of cast products.

Effects of Microstructure on Material Behaviors of Solder Alloys

2005 ◽  
Vol 297-300 ◽  
pp. 825-830 ◽  
Author(s):  
Tae Kyung Hwang ◽  
Soon Bok Lee
Keyword(s):  
Electronic Devices ◽  
Ternary Eutectic ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Cu Alloys ◽  
Material Behaviors ◽  
Elongation To Failure ◽  
Process Behavior ◽  
Free Solder

The leading candidates for replacing lead-contained solders are near ternary eutectic Sn/Ag/Cu alloys. The electronic industry has begun to study both the process behavior and the reliability assessment of these alloys in detail to figure out their applicability to electronic devices and products. In recent publications, the solidification behavior and the fatigue life of the accelerated thermal cycle test have been reported in terms of microstructure variations such as the formation of large Ag3Sn plates and their effects. In this study, coupon type bulk specimens have been made for uniaxial tensile test by casting. To consider the effects of microstructure, casting cooling rates were controlled to 0.02-2.0 oC/sec. Eutectic Sn/Pb and near eutectic lead-free solder materials – Sn/Ag/Cu and Sn/Cu alloys – were used in mechanical testing. Also, nanoindentation tests were performed to measure Young’s modulus of materials having different microstructures. Tensile tests were performed at 3 different strain rates and then acquired 0.2% offset proof stress, ultimate tensile strength and elongation to failure.

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