Interfacial Reaction Behavior Research Articles

Effect of Si element on the interfacial reaction of Ti3SiC2 reinforced Al matrix aomposites

The interfacial reaction behavior of Ti3SiC2/Al andTi3SiC2/Al-10si matrix composites at high temperature was studied by XRD and SEM. The results showed that the reaction between Ti3SiC2 and Al matrix is Ti3SiC2 particles in the Ti3SiC2/Al composite were almost completely reacted after 700 °C/1 h treatment, whilea large amount of Ti3SiC2 particles still existed in the Ti3SiC2/Al-10Si composite under the same treatment condition. In addition, the friction coefficient and wear amount of Ti3SiC2/Al composite were 0.54 and 0.167 g, respectively, and that in Ti3SiC2/Al-10Simatrix composites were 0.29 and 0.019 g. According to the critical condition of ΔG = 0, it is calculated that when the activity of Si is greater than 0.57, the interfacial reaction between Ti3SiC2 and Al matrix is inhibited.

Liquid-State Interfacial Reactions of Sn and Sn-Ag-Cu Solders with p-Type (Bi,Sb)2Te3 Thermoelectric Material

Liquid-state interfacial reactions of p-type (Bi,Sb)2Te3 thermoelectric (TE) material with Sn and Sn-3.0 wt.%Ag-0.5 wt.%Cu (SAC305) solders, respectively, were examined at 250°C on a commercial highly orientated (Bi,Sb)2Te3 substrate with a (110) soldering plane. For the reactions with Sn, the initial reaction phase was the porous SnTe intermetallic compound (IMC). Then, a dense SnTe layer with many tiny cracks formed between the porous phase and TE substrate. With longer aging time, the dense SnTe gradually changed to the porous phase due to Sb dissolution. In the subsequent stage, the reaction phase zone included porous SnTe, an alternating layer microstructure of SnTe and liquid solder, and SnTe/Sn3Sb2 alternating layers from the solder to TE. The IMC growth was extremely fast, being approximately 15 μm/min, and nearly linear with aging time, suggesting reaction control. For the reactions with SAC305, a similar microstructure of porous SnTe and the dense layer was observed. Compared with the reactions with Sn, however, the IMC growth rate was greatly suppressed by ~ 80%. This can be attributed to the Ag-rich phase layer between the dense SnTe and (Bi,Sb)2Te3. Ag was verified to be the key element for dramatically changing the interfacial reaction behavior.

Joint properties enhancement for PbTe thermoelectric materials by addition of diffusion barrier

PbTe-based alloys are potential mid-temperature thermoelectric materials due to their excellent thermoelectric properties. Formation of intermetallic deteriorates mechanical joint strength and thermoelectric performance as well. In the present work, interfacial reaction, electrical and mechanical behaviors for both p- and n-PbTe joints with an addition of diffusion barrier layer are investigated. The results show that Co–P is a suitable barrier layer for PbTe-based thermoelectric devices with Cu or Ni electrode to inhibit the growth of massive intermetallic compound formation caused by fast interdiffusion in Cu/p-PbTe joints and melting of the joints in Cu/n-PbTe joints. Directly bonded Ni electrode induced formation of needle-like IMCs and disintegration of the electrodes in p- and n-PbTe modules respectively. Severe interfacial problems were overcome by adding a Co–P diffusion barrier, mechanical strength was improved. In addition, the Co–P layers enhanced the thermoelectric properties of the joints. The addition of the barrier layer increased 27% and 109% of the zT for p- and n-type joints, respectively.

Interfacial reaction behavior and mechanical properties of pure aluminum and magnesium alloy dissimilar materials fabricated by hot press and heat treatment

Interfacial reaction behavior and mechanical properties of pure aluminum and magnesium alloy dissimilar materials fabricated by hot press and heat treatment

Effect of interfacial reaction behavior on the submerged entry nozzle by the electric current pulse

To clarify the clogging and erosion process of the submerged entry nozzle under an electric field, a clearer and more intuitive understanding of the formation process of clogging and the erosion mode of the submerged entry nozzle were studied in this paper. The results showed that the electric current pulse applied on the submerged entry nozzle can effectively restrain erosion and maintain the integrity of the submerged entry nozzle. After electric current pulse treatment, the density of clogging is increased, and the boundary layer of clogging at different stages is clear. The clogging of the newly formed layer is more stable and can effectively resist erosion-flushing of molten steel. Meanwhile, the inclusion size in steel is refined, which is helpful for improving the quality of steel. Unfortunately, the inhibiting effect will also gradually weaken with increased thickness of the clogging during the electric current pulse treatment.

Influence of Bi Addition on Pure Sn Solder Joints: Interfacial Reaction, Growth Behavior and Thermal Behavior

The effects of different Bi contents on the properties of Sn solders were studied. The interfacial reaction and growth behavior of intermetallic compounds (IMCs) layer (η-Cu6Sn5 + e-Cu3Sn) for various soldering time and the influence of Bi addition on the thermal behavior of Sn-xBi solder alloys were investigated. The Cu6Sn5 IMC could be observed as long as the molten solder contacted with the Cu substrate. However, with the longer welding time such as 60 and 300 s, the Cu3Sn IMC was formed at the interface between Cu6Sn5 and Cu substrate. With the increase of soldering time, the thickness of total IMCs increased, meanwhile, the grain size of Cu6Sn5 also increased. An appropriate amount of Bi element was beneficial for the growth of total IMCs, but excessive Bi (⩾ 5 wt%) inhibited the growth of Cu6Sn5 and Cu3Sn IMC in Sn-xBi/Cu microelectronic interconnects. Furthermore, with the Bi contents increasing (Sn-10Bi solder in this present investigation), some Bi particles accumulated at the interface between Cu6Sn5 layer and the solder.

Mechanical properties and microstructure evolution of dissimilar Mg and Al alloys welded using ultrasonic spot welding

Magnesium and aluminum alloys are used in the development of lightweight materials for the automobile industry. Ultrasonic metal welding is a solid-state bonding technology widely used in lightweight metal welding that has unique advantages for welding dissimilar Mg-Al alloys. In this work, the mechanical properties and interfacial reaction behavior of ultrasonically spot-welded joints of dissimilar Mg-Al alloys were studied using a universal tensile testing machine, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The results showed that the joint strength first increased and then decreased as the welding energy increased. At a welding energy of 980 J, the maximum peeling force of the joint was 0.107 kN, and the failure mode of the weld occurred via a ‘local Al alloy nugget pull-out’. At a welding energy of 1540 J, a continuous ∼20 μm thick intermetallic compound (IMC) layer composed of Al12Mg17 and Al3Mg2 phases formed at the welding interface, which deteriorated the mechanical properties of the joint. As the interfacial temperature increased along with the welding energy, mixed particles formed, and element diffusion accelerated at the interface, which promoted growth of the IMC layer. Dynamic recrystallization occurred near the weld interface under shear deformation as well as deformation heating, which refined the grain size and changed the texture.

Interfacial reaction between YSZ electrolyte and La0.7Sr0.3VO3 perovskite anode for application

The synthesis and performance of La0.7Sr0.3VO3/YSZ composites are investigated as alternative anodes for the direct utilization of methane (i.e., biogas) in solid oxide fuel cells. In this study, the structural stability between Sr-doped lanthanum vanadate and yttria-stabilized zirconia was investigated by using the powder mixture annealed at various periods of time and temperatures. The chemical reaction between these two materials in the temperature ranging from 1100 to 1400 °C was examined by X-ray diffraction (XRD) and electron probe microanalysis (EPMA) analyses. According to the examination of La0.7Sr0.3VO3/YSZ powder mixture after heat treatment at 1100–1400 °C, no second phase was detected when the La0.7Sr0.3VO3/YSZ powder mixture was heated at 1100 °C. The reaction products of perovskite SrZrO3 were formed when the specimens were heated treatment at over 1200 °C. Owing to the further diffusion of Sr cations from La0.7Sr0.3VO3 toward the reaction layer/YSZ interface via the reaction layer, the reaction layer was extended into the YSZ. The interfacial reaction behavior between electrode and electrolyte pellets of the reaction couple was examined by EPMA. No reaction products were observed as La0.7Sr0.3VO3/YSZ composite co-fired at 1100 °C. The reaction products of perovskite SrZrO3 were formed when the specimens were heat treated at over 1200 °C. The bonding energy between La-O (188 kcal/mol) is stronger than Sr-O (83.6 kcal/mol). Thus, Sr ions tend to migrate and react with YSZ much faster than La ions. Furthermore, when the Sr concentration increases to 70%, excess of SrZrO3 formation leads to the phase decomposition of perovskite La0.3Sr0.7VO3.

Ab initio molecular dynamics simulation on interfacial reaction behavior of Fe-Cr-Ni stainless steel in high temperature water

The interfacial reaction behavior of Fe-Cr-Ni stainless steel in 320 °C high temperature water is investigated using an ab initio Born-Oppenheimer molecular dynamics simulation. After the Fe-Cr-Ni stainless steel is immersed in water, the water molecule is dissociated into OH and H ions. The dissociated OH makes bond with the Cr and Fe atoms to form (Cr,Fe)-OH hydroxide, and the dissociated H adsorbs on the Fe atoms with a certain negative charge. The surface layers of Fe-Cr-Ni stainless steel are negatively charged before immersion, whereas after immersion there is a net positive charge in the surface layers. Most of the valence electrons lost from the surface layers transfer to the water solution through the interface, only a small amount of electrons comes into the inner layer atoms of Fe-Cr-Ni stainless steel. The dissociation characteristics of dissolved oxygen molecule and dissolved hydrogen molecule in high temperature water are also analyzed, and both of them can enhance the interfacial charge transfer.

Influences of Ag addition to Sn-58Bi solder on SnBi/Cu interfacial reaction

In this study, the influences of Ag addition to Sn-58Bi solder on SnBi/Cu interfacial reaction and fracture behavior of the aged SnBiAg/Cu solder joints were investigated. The results reveal that the Ag element in the solder can diffuse into the Cu substrate during the soldering and aging process, forming a Cu-Ag alloy layer around the joint interface. The Bi segregation was not observed at the aged SnBiAg/Cu interface, and the embrittlement will not occur at the aged SnBiAg/Cu solder joints once the Bi segregation was restrained.

Interfacial reaction and microstructure study of DSS/Cu/Ti64 diffusion-welded couple

In the present study, the interfacial reaction and microstructure behavior of diffusion-welded joints (DWJs) between duplex stainless steel (DSS) and Ti–6Al–4V alloy (Ti64) with copper interlayer were investigated. The joints were carried out at 825, 850, 875 and 900 °C temperature for 60 min under 4 MPa uniaxial pressure in vacuum. Welded joint was characterized by light microscopy and scanning electron microscopy using backscattered electron mode. Layer-wise Cu4Ti, Cu2Ti, Cu4Ti3, CuTi and CuTi2 intermetallic phases were formed at the Cu–Ti64 interface and the width of the intermetallic layers increases with increase in welding temperature. However, the DSS–Cu interface was completely free from intermetallics. The activation energy and interfacial energy of reaction phases was calculated at the interface. The activation energy values showed that the CuTi intermetallic grew faster than the other phases of the Cu–Ti-based reaction. However, CuTi2 phase first nucleates than the other Cu–Ti-based intermetallics due to its lowest interfacial energy. The highest joint tensile strength of ~ 516 MPa (~ 79% of DSS) along with ~ 6.6% ductility was achieved at 875 °C processing temperature.

Cu-Sn Intermetallic Compound Joints for High-Temperature Power Electronics Applications

Cu-Sn solid–liquid interdiffusion (SLID) bonded joints were fabricated using a Sn-Cu solder paste and Cu for high-temperature power electronics applications. The interfacial reaction behaviors and the mechanical properties of Cu6Sn5 and Cu3Sn SLID-bonded joints were compared. The intermetallic compounds formed at the interfaces in the Cu-Sn SLID-bonded joints significantly affected the die shear strength of the joint. In terms of thermal and mechanical properties, the Cu3Sn SLID-bonded joint was superior to the conventional solder and the Cu6Sn5 SLID-bonded joints.

The growth behavior of interfacial intermetallic compound between Sn–3.5Ag–0.5Cu solder and Cu substrate under different thermal-aged conditions

The interfacial reaction, morphology, activation energies and growth behavior of interfacial intermetallic compounds (IMCs) between the Sn–3Ag–0.5Cu (in wt%) solder and Cu substrate during reflow at 280 °C for 10 min and aging at different temperatures for up to 360 h were investigated, and the growth kinetics of the interfacial Cu–Sn binary IMC layers were monitored during the isothermal aging. The results showed that the thickness of IMCs increased linearly with square root of aging time, and the diffusion coefficient related to the Cu–Sn IMC layer increased with increasing aging temperature. During aging at medium temperature (180 °C), the scallop-like Cu6Sn5 IMC layer at the SAC305/Cu interface gradually transformed into planar type with prolonged aging time. Nevertheless, in the case of high temperature (200 °C) aging, the solder/Cu6Sn5 interface became uneven because the Cu atoms came from the bulk solder would accumulate on the Cu6Sn5 IMC surface to directly thicken the existed IMC layer. Beside, the Kirkendall voids within Cu3Sn layer and the neighborhood of the Cu3Sn/Cu interface almost aggregated into continuous regions to formed micro-voids. The activation energies of the total Cu–Sn, Cu6Sn5 and Cu3Sn IMCs were obtained by plotting the diffusion constants (D) as a function of the aging temperature (1/T), and were 115.2, 122 and 98 kJ/mol, respectively.

Interfacial reaction behavior and bonding mechanism between liquid Sn and ZrO2 ceramic exposed in ultrasonic waves

Ultrasound-assisted dipping of ZrO2 ceramics into molten Sn solder was performed to realize the low-temperature joining of ZrO2 ceramics in this study. Scanning electron microscopy with energy dispersive spectrometer, X-ray diffraction and X-ray photoelectron spectroscopy were employed to study the effects of ultrasonic vibration on the microstructure of Sn/ZrO2 interface, and to elucidate the joining mechanism between Sn coating layer and ZrO2 ceramic. Results showed that, after ultrasonically dipping in molten Sn for 1200s, a pure Sn solder layer with a thickness of approximately 8–9µm was coated on the ZrO2 surface. The Sn coating layer exhibited excellent metallurgic bonding with ZrO2 ceramic. A nano-sized ZrSnO4 ternary phase, which was beneficial to the smooth transition of the lattice from Sn solder to ZrO2 ceramic, was formed at the Sn/ZrO2 interface. The formation of ZrSnO4 interlayer was ascribed to the acoustic cavitation induced high-temperature reaction of Sn, O and ZrO2 at the molten Sn/ZrO2 ceramic interface. The tested average shear strength of ZrO2/Sn/ZrO2 joints was approximately 32MPa, and the shearing failure mainly took place within the Sn solder layer.

Microstructure evolution and shear behavior of Au–Sn/Ni–xCo (x = 20, 40, 60, and 80 at.%) joints soldered at 350 °C

Interfacial reaction and shear behavior of the joints between the Au–29Sn (at.%) solder and the Ni–xCo (x = 20, 40, 60, and 80 at%) alloys soldered at 350 °C for various durations were investigated in this study. The results show that Ni3Sn2 is the common reaction product at the solder/substrate interfaces after soldering regardless of the Co content, but the morphology and growth kinetics of Ni3Sn2 are closely related to the Co content of Ni–Co substrates. With increasing of Co content in Ni–Co substrates, the growth rate of Ni3Sn2 decreases, and the needle-like shaped Ni3Sn2 grain changes to lath-shaped type. In addition, the thickness of the Ni3Sn2 layer maintains at about 7 μm even after long duration due to depletion of Sn in the solder matrix. The shear strength of Au–Sn/Ni–xCo joints is sensitive to the thickness of Ni3Sn2 layer. It can achieve about 45 MPa and maintain above 40 MPa if adequate thickness of Ni3Sn2 layer, typically 2–5 μm, is obtained at the interface.

Interfacial Microstructure Evolution and Shear Behavior of Au-Sn/Ni-xCu Joints at 350°C

Interfacial reaction and shear behavior of the joints between Au-29Sn (at.%) solder and Ni-xCu (x = 20 at.%, 40 at.%, 60 at.%, and 80 at.%) substrate alloys soldered at 350°C for various durations were investigated in this study. The results show that α(Au) is the common reaction product at the solder/substrate interfaces after a short-time reaction regardless of Cu content. As soldering goes on, another new Ni3Sn2 layer forms at the interface company with ordering of the α(Au) phase, AuCu I/Ni3Sn2 bi-layers formed at the Au-Sn/Ni-20Cu interface, or with AuCu III/Ni3Sn2 bi-layers at the Au-Sn/Ni-40Cu interface. If the content of Cu in the substrate is higher than 40 at.%, periodic layered structure and discontinuous Ni3Sn2 layers appear. In the couple of Au-Sn/Ni-60Cu, AuCu I + AuCu III/Ni3Sn2/α(Au) can be observed while AuCu3/Ni3Sn2/α(Au) forms in the couple of Au-Sn/Ni-80Cu. Shear fracture always occurs in the region near the Ni-20Cu substrate in Au-Sn/Ni-20Cu joints, whereas it appears in the reaction layer for the joint of higher Cu content. The shear strength of Au-Sn/Ni-60Cu and Au-Sn/Ni-80Cu joints achieves about 55 MPa as α(Au) phase forms but decreases remarkably due to pore formation after soldering for a long duration. Whereas, the shear strength of Au-Sn/Ni-40Cu joints can reach 62 MPa as the α(Au) phase forms at an early stage, and maintains above 52 MPa even soldered for a long duration because of the adequate thick α(Au) and AuCu III layer adjacent to substrate provides good bonding. The reason why the soldering joint of Au-Sn/Ni-40Cu possesses higher strength and a better stability exists is that high Ni concentration in α(Au) and the continuous Ni3Sn2 layer inhibit formation of Kirkendall pores.

Effect of in Addition to Zn-5Al Solder on Microstructure and Properties of Solder Joints

The effect of In addition to Zn-5Al on the interfacial reaction behaviors and mechanical properties of solder joints were investigated. It was found that addition of In decreasing the melting point of Zn-5Al solder. The segregation of In on grain boundary was observed. CuZn5 and Cu5Zn8 intermetallic phases were observed at joint interface. Segregation of In on grain boundary caused a significant decrease of strength of the Zn-5Al-In solder compared to Zn-5Al. Addition of 1% In to Zn-5Al solder resulted in a reduction of shear strength of 14 MPa. The interfacial microstructure, shear strength and fracture surfaces of Zn-5Al/Cu and Zn-5Al-1In/Cu solder joints were studied.

Effects of Heat Treatment on Microstructure and Corrosion Behavior of SiC p /Al-6wt%Mg Composites

The present work investigated the influence of heat treatment (T1, T4, T6 and annealing) on the microstructure related to the interfacial reaction and corrosion behavior of SiC p /Al-6wt%Mg composites prepared by a pressureless infiltration technique. The results show the occurrence of the precipitates of Si, MgA1 2 O 4 and Mg 2 Si as a result of the interfacial reaction between the SiC particle and the matrix of the composites during heat treatment. The precipitates contents ( f ) of the composites correlate with T1, T4, T6 and annealing heat treatment, following the order of f T1 < f T4 < f T6 < f annealing . The precipitates near SiC particles are responsible to pitting corrosion as a degradation mechanism of the composites. The heat treatments carried out on the composites present a significant influence on the corrosion rate ( j corr ). The correlation between j corr and heat treatment shows the characteristic of j corr-ann > j corr-T6 > j corr-T4 > j corr-T1 , which may be attributed to the interfacial reaction precipitates of the composites during heat treatment.

Magnesium Storage Performance and Surface Film Formation Behavior of Tin Anode Material

AbstractElectrochemical cycling performance of microsize bulk and thin film Sn electrodes up to 50 cycles in Mg half‐cell configuration, as well as Mg diffusivity and interfacial reaction behavior in a phenylmagnesium chloride (PhMgCl)/THF electrolyte are studied. The bulk Sn electrode delivers capacities of 321–289 mAh g−1 with capacity retention of 90 % and coulombic efficiencies higher than 99 % over 30 cycles, and thus demonstrates the potential of Sn anodes. The Sn film electrode shows good cycling ability. Surface analysis by XPS reveals that the surface of cycled electrodes is composed of a mixture of various inorganic salts of Sn and Mg formed by interfacial reactions between Sn and PhMgCl, and organic functionality produced by decomposition of THF, indicating surface film formation. The Mg2+ diffusivity of Sn is on the order of 10−11 cm2 s−1, which is four orders of magnitude lower than the Li+ diffusivity of Sn in Li‐ion batteries. Advanced material design for enhanced electronic conductivity and control of the interfacial chemistry for formation of a surface protective film are believed to be the keys to overcome such sluggish kinetics, increase the capacity, and improve the cycling performance.

Cycling Performance and Interfacial Phenomena of High-Energy Li-Ion Battery with Sulfur-Based Cathode and Silicon-Based Anode

Li-ion battery market is currently expanding from small, portable batteries to electric vehicles and energy storage systems. To meet the demands, more than doubled energy density than that of currently used batteries is required. The energy density of current batteries, which consist of lithium metal oxide cathode and graphite anode materials, is however limited. A general approach to increase the energy density of a battery is the replacement of current cathode and anode active materials to higher capacity materials, and electrolyte that is interfacially compatible to them. Recently, sulfur-based cathode and silicon-based anode materials are considered as one of the most promising active materials for high-energy batteries. Earlier reports on sulfur-based cathode and silicon composite anode in half-cells showed a good cycling performance.1,2 However, there are just a few reports on the full-cell with those materials.3,4 To date, the best performance of full-cell was obtained when being assembled with carbon composite of elemental sulfur cathode, lithiated nanosphere Si/SiOx anode and a polysulfide-containing electrolyte, showing the capacity of 750 mAhg-1 and capacity retention of 85 % at the 500th cycle.3 However, the combination of sulfur-based cathode and silicon-based composite anode in a full-cell face several common issues such as the lack of Li+ source of sulfur cathode, solvent intercalation into graphite anode, and possible interfacial reaction between anode and soluble polysulfide formed during cycling. To overcome those issues, researchers have used Li2S instead of sulfur, fabricated anode with functional binder to prevent solvent intercalation, and modified electrolyte with polysulfide additive.3-5 However, interfacial reaction behavior in full-cells is unknown. In this study, we demonstrate good cycling performance of a full-cell composed of a new micron-sized sulfur-based cathode material and submicron-sized lithiated silicon-based anode material. Correlation between the cycling performance and interfacial phenomena would be discussed in the meeting. Acknowledgements This work was supported under the framework of international cooperation program managed by National Research Foundation of Korea (2015K2A5A3000068) and German Academic Exchange Service (57141898), and by the Ministry of Trade, Industry & Energy (10049609) of Korea, and Nano-Material Technology Development Program by the Ministry of Science, ICT and Future Planning (2009-0082580) of Korea.