Ti-Cu Intermetallic Compounds Research Articles

Optimization of the active element and reinforcement proportion for improving joint strength of brazed Si3N4/42CrMo

Micron-TiN particles and Ti powder were introduced into the AgCu powder filler to design a particle-reinforced composite filler. This TiN particle (TiNp) modified brazing material was adopted to reliably braze Si3N4 ceramics onto 42CrMo steel, and the ratio of active element Ti to TiNp reinforcement was optimized for joint strength improvement. The reaction layer’s thickness (TiN+Ti5Si3) adjacent to the ceramic decreased by introducing TiNp. Nevertheless, the reaction layer’s thickness (TiC) at the 42CrMo side did not vary too much. TiNp showed excellent wettability with Ag-Cu-Ti braze, and there was no obvious reaction at the interface. Cu-Ti intermetallic compounds were formed and randomly distributed in the brazing seam. When the TiNp content did not exceed 8 vol.%, the joints’ mechanical properties first sharply decreased and then remained basically unchanged when Ti increased. Raising the TiNp content to 10 vol.%, the joint strength showed the changing trends of first increasing and then dropping by increasing Ti content. The bending strength reached the maximum value of 396 MPa when 8 vol.% TiNp and 4 wt.% Ti were adopted.

Improving bonding strength and reliability of brazed titanium/copper dissimilar joint using vanadium interlayer

Conventional practice of brazing titanium (Ti) to copper (Cu) using Ag-28Cu eutectic filler alloy is of limited success because of the generation of brittle Ti-Cu intermetallic compounds (IMCs). The bonding strength is unsatisfactory owing to embrittlement of IMCs, and it is difficult to reproduce the bonding strength as the joint microstructure is highly sensitive to brazing parameters. In the current study, it was demonstrated that the formation of such undesirable IMCs can be suppressed and strong Ti/Cu joint can be obtained by brazing at 850 °C using a refractory vanadium (V) interlayer 15 μm in thickness deposited on Ti substrate, in combination with an Ag-Cu-Ti active filler alloy. The V interlayer successfully blocked the interaction between Ti and filler alloy. Bonding mechanisms of the resultant joint can be deduced to be a synergy of active brazing in the V/Ag-Cu-Ti/Cu half and solid-state diffusion bonding at the Ti/V interface. The thus developed joint was comprised of continuous Ti-V solid solution, unconsumed V interlayer and remaining filler alloy. Attributed to elimination of brittle IMCs at joint interface, excellent bonding strength of ∼220 MPa which is comparable with strength of Cu base metal was achieved. Moreover, since the joint evolution was dominated by sluggish solid-state diffusion at the Ti/V interface and very limited erosion of V interlayer by the Ag-Cu-Ti filler, desirable IMC free joint can be obtained over a wide range of brazing time (2 ∼ 5 min), enabling outstanding reliability of the high bonding strength.

Electromigration-enhanced Kirkendall effect of Cu/Ti direct diffusion welding by sparking plasma sintering

Electromigration-enhanced Kirkendall effect is firstly observed in Cu/Ti diffusion welding by sparking plasma sintering. Microstructural evolution and mechanical properties of Cu/Ti joints were systematically investigated to clarify the electromigration-enhanced Kirkendall effect on the mechanism of diffusion joining. Four types of Cu-Ti intermetallic compounds were formed at the interface of bonded joint: CuTi2, CuTi, Cu3Ti2, and β-Cu4Ti. At welding temperature less than 833 K, Cu atomic diffusion was enhanced by current, leading to large Kirkendall Voids along the Cu matrix near intermetallic, resulting in low joint strength. However, as the welding temperature increased to 833 K, a continuous CuTi2 Kirkendall plane was formed in the β-Cu4Ti compound layer, and the growth of the brittle CuTi phase was impeded. A notable observation of this study is that the temperature range for manufacturing high-strength Cu/Ti joints diffusion welding by SPS was determined to be 813–863 K, which is much wider than that reported in the literature. The maximum average shear strength of the joints welded at 833 K was 103.1 MPa, which is twice as large as the value commonly reported. This difference is attributed to the suppression of the brittle CuTi phase by the electromigration-enhanced Kirkendall effect.

Interfacial evolution behavior and mechanical properties of Ti/steel joint via ultrasonic seam assisted resistance spot welding with Cu interlayer

Ultrasonic seam assisted resistance spot welding, as a new joining technology, was proposed for welding TC4 titanium alloy and Q235 mild steel with Cu interlayer (abbreviated as US-RSW-Cu), in which, the Cu interlayer was consolidated on the Q235 mild steel by ultrasonic seam welding (USW) in advance, which was subsequently connected with TC4 by the traditional standard resistance spot welding (RSW) in the following experiments. To investigate the effect of pre-USW on the interface microstructure and mechanical properties, the final joints were compared with the other joints by the traditional RSW without interlayer directly (abbreviated as RSW-D), and with a single Cu interlayer (abbreviated as RSW-Cu). The results depicted that the welding nugget in RSW-D and the flat interfacial structure in RSW-Cu were replaced by the inhomogenous interfacial structure in US-RSW-Cu due to the pre-metallurgical bonding between Cu interlayer and steel by USW, which also effectively decreased the welding defects. The Ti-Cu intermetallic compounds (IMCs) were generated at the final joints via US-RSW-Cu instead of most Ti-Fe IMCs, which improved significantly the joint properties and reduced the nanoindentation hardness at the joint interface. The final shearing force of welding joints by this method was the highest and reached 12,380 N, which was 2.68 times with original joint strength via a single RSW-D. The reaction layer near the Ti side via US-RSW-Cu contained abundant Fe atoms, forming Ti-Cu and TiFe2 IMCs at this position. The final welded specimen fractured at the interfacial reaction layer near the Ti side due to the generation of TiFe2 IMC. The XRD results also proved the generation of the abovementioned Ti-Cu and Ti-Fe IMCs.

Microstructure and Mechanical Properties of GH4169 Superalloy and Si3N4 Ceramic Joints Brazed with AgCuTi/Cu foam/AgCuTi Composited Filler

GH4169 superalloy and Si3N4 ceramics were vacuum-brazed with AgCuTi+Cu foam composite filler. The effect of brazing temperature on the microstructure and mechanical properties of the GH4169/Si3N4 joint was studied. The results show that the interface microstructure of the GH4169/Si3N4 joint is the GH4169 superalloy/TiCu+Ti2Ni+TiCu2+Ag(s, s)+TiCu4+Cu(s, s)+TiN+Ti5Si3/Si3N4 ceramics. With the increase in brazing temperature, the element diffusion between the base metal and the brazing filler intensifies, and the interfacial reaction layer thickens, which is conducive to the improvement of shear strength. At 850 °C, the maximum shear strength of the joint is 196.85 MPa. After further increases in the brazing temperature, Cu foam dissolves completely, and the Ti-Cu intermetallic compounds increase, which is harmful to the shear strength due to the increases in the brittle phase. However, when the brazing temperature reaches 910 °C, the shear strength of the brazing joint slightly increases under the combined effect of the Ti-Cu intermetallic compounds and the thickness of the reaction layer.

Strength optimization of two-step-bonded Ti-6Al-4V/Si3N4 joint with Nb interlayer via transient-liquid-phase bonding and active-metal brazing

A novel two-step bonding of Ti-6Al-4V/Si3N4 joint was developed with Nb interlayer as residual-stress reliever via low-pressure transient-liquid-phase bonding (TLPB) of Ti-6Al-4V/Nb side prior to active-metal brazing of Nb/Si3N4 side. While 1.75 mass% of Ti in a 50-µm-thick CUSIL-ABA® filler was sufficient for sound bonding at Nb/Si3N4 side when brazed at 1103 K for 10 min, one-step-brazed joints with bonding area of 10 × 10 mm2 were prone to failure at the Ti-6Al-4V/Nb side due to brittle Cu-Ti intermetallic compounds (IMCs). Replacing brazing of Ti-6Al-4V/Nb side with TLPB using pure Cu and Ni foils as filler at 1213 K for 180 min eliminated the formation of brittle IMCs via homogenization of (α + β)-Ti; bending strength increased to 193 MPa with residual-stress-induced failure from Si3N4 ceramics. Finally, effectiveness of stress-accommodation via Nb interlayer and filler’s plastic flow was quantitatively verified with reasonable fidelity by finite-element analysis incorporating temperature-dependent elasto-plastic properties.

Strong Mo/Cu interfacial bonding facilitated by consumable Ti interlayer

It is challenging to construct interfacial metallurgical bonding in Mo/Cu immiscible system because of the lack of mutual solubility. Here it was demonstrated that such problem can be effectively circumvented and robust Mo/Cu interfacial bonding can be achieved by diffusion bonding at 800 °C using a thin Ti interlayer. At the initial stage, bonding was made by forming MoTi solid solution (s.s) and TiCu intermetallic compounds (IMCs). The presence of IMCs was detrimental to joint integrity, leading to poor bonding strength. Prolonged bonding duration resulted in dilution of Ti and progressive elimination of TiCu IMCs. Ultimately, IMCs free joint exhibiting excellent interfacial bonding strength comparable with Cu base metal properties was obtained at bonding duration of 60 min.

Residual stress induced failure of Ti-6Al-4V/Si3N4 joints brazed with Ag-Cu-Ti filler: The effects of brazing zone’s elasto-plasticity and ceramics' intrinsic properties

The residual-stress induced failure of Ti-6Al-4V/Si3N4 joints brazed with two different Si3N4 ceramics possessing different intrinsic properties was elucidated through experimental and finite-element (FE) thermo-mechanical simulations incorporating the local elasto-plastic properties of the as-received Ag-Cu-Ti filler and the brazing zone characterized by nano-indentation. All tested joints fractured mainly from the ceramics due to residual stress, and their bending strengths increased when using Si3N4 ceramics of higher intrinsic strength. FE-analysis based on the as-received filler’s properties overestimated the nominal bending strengths by approximately 100 MPa in both joints; nano-indentation revealed that the depletion of ductile Ag-Cu phase and growth of hard Cu-Ti intermetallic compounds reduced the plastically deformable thickness after being brazed, whereby they resulted in higher residual stress in the ceramics. Finally, the validity of FE-estimated bending strengths was enhanced when considering the effective plastically deformable thickness of filler (30 μm) instead of the as-received state (50 μm).

Study on weld formation and segregation mechanism for dissimilar pulse laser welding of NiTi and Cu wires

In this study, laser microwelding was adopted to join NiTi and Cu wires using different laser pulse duration. The cross section of welded samples showed no visible defect, but some intermetallic compounds were formed inside the fusion zone. An excellent metallurgic bonding was achieved during laser welding for NiTi and Cu wires with increasing pulse duration. Local element segregation like peninsulas and beaches was observed in the fusion zone for the pulse duration of 5 and 8 ms, but the segregation was absent with the pulse duration increased to 15 ms. The liquidus temperatures of weld metals in molten pool had a significant effect on the segregation formation. If TLW < TLNiTi/TLCu, a NiTi/Cu peninsula can form near the fusion boundary of NiTi/Cu side, while a NiTi/Cu beach can form if TLW > TLNiTi/TLCu. With increasing pulse duration, the fraction of Ni-Ti brittle intermetallic compounds in the fusion zone decreased, but Cu-Ti intermetallic compounds with lower hardness increased. Little hardness variation was achieved and peak hardness values decreased (~630 → ~560 → ~490 HV). The joint with the pulse duration of 5 ms displayed poor mechanical properties due to uncompleted penetration. Fracture occurred in Cu base metal for the pulse duration of 8 ms and 15 ms. This study showed that it was potential to diminish the brittle intermetallic compounds and improve the mechanical properties of fusion zone by adjusting the laser pulse duration for the dissimilar laser welding of NiTi and Cu wires.

Determining the mechanisms of dissolution and isothermal solidification kinetics during transient liquid phase bonding of commercially pure titanium using a pure copper interlayer

Brazing of Ti with pure Cu interlayers has become increasingly important in efforts to reduce the cost of manufacturing in the aerospace industry. A detailed understanding of the dissolution behaviour and kinetics of isothermal solidification in Ti/Cu joints was determined to promote the further development of this brazing technology. During heating Ti-Cu intermetallic compounds form at the solid/liquid interface which impede diffusion of copper into the base metal but quickly consume to pure Cu foil. Temperatures above the melting point of the Ti2Cu-TiCu eutectic (960 °C) are needed before significant liquid phase forms and dissolution of the base metal accelerates once heating above the Ti rich peritectic of 1005 °C occurs. Maximum dissolution and gap widening occurs just as the braze temperature of 1050 °C is reached, followed by a rapid isothermal solidification (IS) rate in the first five minutes of the isothermal hold. Following this rapid IS stage, the rate becomes constant with the square root of braze time. The experimental results and predictions from this work indicate that decreasing the Cu interlayer thickness from 100 to 25 μm reduces the isothermal solidification time from 226 to 7.56 min respectively. Brazing with a 50 μm gap for 75 min created a dense homogenized joint with a centerline concentration of 3 wt% Cu.

Brazeability, Microstructure, and Joint Characteristics of ZrO2/Ti-6Al-4V Brazed by Ag-Cu-Ti Filler Reinforced with Cerium Oxide Nanoparticles

In this work, we have attempted to develop the Ag-Cu-Ti filler for bonding ZrO2 to Ti-6Al-4V. The CeO2 nanoparticles were reinforced in the eutectic Ag-Cu-Ti filler via mechanical mixing and melting route. Furthermore, the brazeability, microstructure, and mechanical behavior, as well as brazing performance of the ZrO2/Ti-6Al-4V joints, were assessed. The wettability of the Ag-Cu-Ti matrix was increased from 89 to 98% on Ti-6Al-4V and from 83 to 89% on the ZrO2 substrate after the addition of 0.05% CeO2. Also, there was a depression in the melting point of the composite fillers up to 3°C. The microstructure consists of Cu- and Ag-rich phases and Cu-Ti intermetallic compounds (IMCs). The joint shear strength was improved with the addition of CeO2 up to 0.05 wt.% in the matrix. It was inferred that, for an excellent brazing performance of the ZrO2/Ti-6Al-4V joint, the optimum amount of CeO2 should be 0.05 wt.% in the Ag-Cu-Ti matrix.

Effect of heat input on microstructure and mechanical properties of Ti/Cu66V34/Cu joints by electron beam welding

The variations of microstructure and mechanical properties of the joints with different welding heat input were investigated. As the heat input increased, excessive melting of TA15 alloy facilitated the formation of Ti-Cu compounds at the TA15 interface, increasing the brittleness of the TA15 interface. Moreover, high heat input also caused the HAZ softening by grain coarsening and deteriorated the performance of the joint. However, low heat input was adverse to the complete melting of Cu66V34 alloy and induced the formation of welding pores. It also weakened the strength of the joint. Under optimum welding parameters, (Ti,V) solid solution formed at the titanium interface, replacing Ti-Cu intermetallic compounds (IMCs). Therefore, the joint of sample 2 presented the highest strength (378MPa) and fractured along the HAZ of QCr0.8 alloy due to the HAZ softening resulting from grain coarsening.

Forming and tensile fracture characteristics of Ti-6Al-4V and T2 Cu vacuum electron beam welded joints

Dissimilar metals of Ti-6Al-4V and T2 Cu were successfully welded by vacuum electron beam. Forming and tensile fracture characteristics of the joints were studied in the paper. Wettability and tensile tests were introduced to reveal the weldability of Ti-Cu joints, meanwhile, OM, SEM, EDS, XRD and TEM were applied to assess the microstructure and fracture mechanism. The results shows that Cu can wet the surface of Ti alloy well, but not the opposite. Thus, shifting the electron beam on Cu sheet is helpful to improve appearance quality and bonding strength. Average tensile strength of Ti-Cu joints could reach 147 MPa, i.e. 63% of that of T2 Cu substrate when the electron beam was shifted to the copper side with an offset of 1.4 mm. The micro analysis demonstrate that there is a thin IMCs layer at the fusion zone. Which consists of a variety of Ti-Cu intermetallic compounds, e.g., Ti2Cu, TiCu, Ti3Cu4, βTiCu4, etc. Fracture morphologies indicate that it belongs to quasi-cleavage fracture and fracture occurred at the IMCs layer.

Investigation on viscosity, surface tension and non-reactive wettability of melting Ag-Cu-Xwt%Ti active filler metals

The microstructure, viscosity and surface tension of melting Ag-Cu-Xwt%Ti active filler metals were researched, the influence mechanism of microstructure on the viscosity and surface tension was discussed, the non-reactive wetting behavior of melting Ag-Cu-Xwt%Ti filler metals on W substrate was investigated. The research results indicate that, the microstructure of Ag-Cu filler metal is composed by Ag86Cu14 phase and Ag56Cu44 phase, while after Ti element be added in the Ag-Cu-Xwt%Ti filler metal, Cu-Ti intermetallic compounds will be formed. The different microstructures of the Ag-Cu-Xwt%Ti filler metals, especially the difference between the amounts and kinds of the intermetallic compounds, lead to the various viscosity and surface tension. Viscosity of the Ag-Cu-Xwt%Ti filler metal can be divided into low temperature zone and high temperature zone. At the low temperature zone, the viscosity increases obviously with the increasing Ti content, while at the high temperature zone, the viscosity for the four melting Ag-Cu-Xwt%Ti filler metals show little difference. With increase of the temperature, surface tension for the four melting Ag-Cu-Xwt%Ti filler metals all decrease firstly and then increase, and the temperature for the lowest surface tension is 975 °C. Moreover, with increase of the Ti content, surface tension of the melting Ag-Cu-Xwt%Ti filler metal increases gradually at both low temperature zone and high temperature zone, but the difference among them at low temperature zone is larger than that at high temperature zone. The non-reactive wetting experimental result confirms this conclusion very well.

Microstructure evolution and mechanical properties of titanium matrix composites and Ni-based superalloy joints with Cu interlayer

This study investigated the joining of TiBw/Ti6Al4V composites and Inconel 718 alloy with Cu interlayer using gas tungsten arc welding (GTAW) equipment in order to modify the joints strength. Microstructure analysis indicated that Ti-Cu intermetallic compounds (IMCs) and a small number of Ti-Ni-Cu compounds were generated in the reaction layer with low heat input. While the main products changed into Ti-Ni-Cu compounds, also combined with Ti-Ni compounds and a few ternary compounds with the increase of heat input. Accordingly, the shear strength of dissimilar joints firstly increased and then decreased with the increase of welding current or the decrease of welding speed. The maximum shear strength (370 MPa) was obtained with the current of 100 A and the speed of 110 mm min−1. Moreover, the hardness of reaction layer was much higher than that of parent materials due to the formation of IMCs, and medium heat input can reduce the hardness mismatch in joints.

Wetting behavior of graphite and CFC composites by Cu-Ti compacts

The wetting behavior of Cu-Ti powder compacts with 22 wt % Ti and 50 wt % Ti on carbon materials, including graphite and carbon fiber reinforced carbon composites (CFC), has been investigated in a vacuum using the sessile drop method. The equilibrium contact angles of Cu-22Ti (containing 22 wt% Ti) on the graphite and the CFC substrates at 1 253 K are 32° and 26°, respectively, whereas the equilibrium contact angle of 9° is obtained for Cu-50Ti (containing 50 wt% Ti) on both the graphite and the CFC substrates at 1 303 K. Microstructural analysis of the wetting samples shows that a thin TiC reaction layer is developed at the interfacial area and Ti-Cu intermetallic compounds are formed over the reaction layer. The investigation on the spreading kinetics of Cu-Ti compacts on carbon materials substrates at fixed temperatures reveals that the spreading is controlled by the interfacial reactions in the first stage and then by the diffusion of the active Ti from the drop bulk to the triple line in the later stage. The spreading is promoted by the intense reaction at higher Ti concentrations.

First-principles calculations on structural energetics of Cu-Ti binary system intermetallic compounds in Ag-Cu-Ti and Cu-Ni-Ti active filler metals

Structural, mechanical and thermodynamic properties, as well as the electronic structures of Cu-Ti binary system intermetallic compounds in Ag-Cu-Ti and Cu-Ni-Ti active filler metals were calculated systematically using a first-principles density functional theory (DFT). The calculated formation enthalpy index that all the Cu-Ti intermetallic compounds are thermodynamic stable from degradation to pure metals and the relationship between Cu content (x) and formation enthalpy (y) for tetragonal structure meets the function y=0.572+(−1.005/(0.048*sqrt(3.142/2)))*exp(−0.5*((x−47.167)/13.533)^2). The mechanical properties, including bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio v, and elastic anisotropy were derived from the elastic data Cij. For the tetragonal Cu-Ti intermetallic compounds, the shear modulus G and Young's modulus E are negatively related to the formation enthalpy, while for the orthorhombic Cu-Ti intermetallic compounds, G and E are positively related to the formation enthalpy. Moreover, the elastic anisotropy increases in the following order: Cu4Ti<CuTi3<Cu4Ti3<Cu2Ti<CuTi<CuTi2<Cu3Ti2. The thermodynamic properties were estimated from the electronic structures and elastic constants simultaneously, and the results found that Cu4Ti possess the best thermal conductivity and heat capacity among all the Cu-Ti intermetallic compounds, while CuTi3 shows the worst ones. Finally, the relationship between electronic structures and physical properties was discussed, and get the inference that for the Cu-Ti intermetallic compounds, the mechanical properties are positively related to the strength of the covalent bond, while the thermophysical properties are influenced by the ionic character and covalent character simultaneously and the ionic character shows the dominant role, therefore, CuTi and Cu4Ti3 show the strongest mechanical properties due to the strongest covalent character, while Cu4Ti shows the strongest thermal conductivity and heat capacity due to the strongest ionic character.

Compressive Strength Evaluation in Brazed ZrO2/Ti6Al4V Joints Using Finite Element Analysis

This study aims to synthesize and evaluate the compressive strength of the ZrO2/Ti-6Al-4V joint brazed using an active metal filler Ag-Cu-Sn-Ti, and its application to dental implants assuring its reliability to resist the compressive failure in the actual oral environment. The brazing was performed at a temperature of 750 °C for 30 min in a vacuum furnace under 5 × 10−6 Torr atmosphere. The microstructure of the brazed joint showed the presence of an Ag-rich matrix and a Cu-rich phase, and Cu-Ti intermetallic compounds were observed along the Ti-6Al-4V bonded interface. The compressive strength of the brazed ZrO2/Ti-6Al-4V joint was measured by EN ISO 14801 standard test method. The measured compressive strength of the joint was ~1477 MPa—a value almost five times that of existing dental cements. Finite element analysis also confirmed the high von Mises stress values. The compressive strains in the samples were found concentrated near the Ti-6Al-4V position, matching with the position of the real fractured sample. These results suggest extremely significant compressive strength in ZrO2/Ti-6Al-4V joints using the Ag-Cu-Sn-Ti filler. It is believed that a highly reliable dental implant can be processed and designed using the results of this study.

Microstructure analysis of graphite/Cu joints brazed with (Cu-50TiH2) + B composite filler

Joining of carbon materials to copper will benefit the fabrication of plasma facing components for fusion applications. Graphite/Cu joints have been prepared by brazing with (Cu-50TiH2)+B composite filler in a vacuum. The effect of boron content in the composite filler on the mechanical property and microstructure of brazed graphite/Cu joints has been investigated. The average shear strength of joints increases with boron content raising from 0 to 15vol%. The maximum average shear strength of 19.8MPa was obtained with boron content of 15vol%. Then, the strength of joints decreases with boron content higher than 15vol%. The microstructure analysis of joints brazed with (Cu-50TiH2)+15vol% B filler indicates that TiB whiskers have been in situ synthesized in the filler layer. The filler layer is mainly composed of Cu based solid solution and Ti-Cu intermetallic compounds with TiB whiskers distributed inside. The distribution of TiB whiskers in the filler layer could serve as reinforcements, contributing to the improvement of graphite/Cu joints.

Impulse Pressuring Diffusion Bonding of Titanium to Stainless Steel Using a Copper Interlayer

Impulse pressuring diffusion bonding of commercially pure titanium to 1Cr18Ni9 stainless steel was carried out using a copper interlayer in an attempt to reduce the bonding time and alleviate the detrimental effect of interfacial reaction products on bonding strength. Successful bonding has been achieved at 850 °C under a pulsed pressure of 8∼20 MPa within a duration of only 120∼180 s, which is notably shortened in comparison with conventional diffusion bonding. Microstructure characterization revealed that a sequence of Ti-Cu intermetallic compounds were formed at the Ti/Cu interface and the Cu/stainless steel interface was characterized by the presence of solid solution of Cu in γ Fe without any interfacial reaction products. Maximum bonding strength of 346 MPa was obtained when the joint was bonded for 120 s. Upon tensile loading, the joints fractured along the Ti/Cu interfacial reaction layer in a brittle cleavage manner, indicating that the impulse pressuring diffusion bonding can alleviate the harmful influence of interfacial intermetallic compounds on joint performances to a certain extent, but it is infeasible in completely eliminating the negative effect of the brittle intermetallic compounds.