The influence of Mo and ZrO_(2)nanoparticles addition on the interfacial properties and shear strength of Sn58Bi solder joint was investigated.The interfacial microstructures of Sn58Bi/Cu,Sn58Bi+Mo/Cu and Sn58Bi+ZrO_(...The influence of Mo and ZrO_(2)nanoparticles addition on the interfacial properties and shear strength of Sn58Bi solder joint was investigated.The interfacial microstructures of Sn58Bi/Cu,Sn58Bi+Mo/Cu and Sn58Bi+ZrO_(2)/Cu solder joints were analysed using a scanning electron microscope(SEM)coupled with energy dispersive X-ray(EDX)and the X-ray diffraction(XRD).Intermetallic compounds(IMCs)of MoSn_(2)are detected in the Sn58Bi+Mo/Cu solder joint,while SnZr,Zr_(5)Sn_(3),ZrCu and ZrSn_(2)are detected in Sn58Bi+ZrO_(2)/Cu solder joint.IMC layers for both composite solders comprise of Cu_(6)Sn_(5) and Cu_(3)Sn.The SEM images of these layers were used to measure the IMC layer’s thickness.The average IMC layer’s thickness is 1.4431μm for Sn58Bi+Mo/Cu and 0.9112μm for Sn58Bi+ZrO_(2)/Cu solder joints.Shear strength of the solder joints was investigated via the single shear lap test method.The average maximum load and shear stress of the Sn58Bi+Mo/Cu and Sn58Bi+ZrO_(2)/Cu solder joints are increased by 33%and 69%,respectively,as compared to those of the Sn58Bi/Cu solder joint.By comparing both composite solder joints,the latter prevails better as adding smaller sized ZrO_(2)nanoparticles improves the interfacial properties granting a stronger solder joint.展开更多
Al-Ti diffusion couples were made by embedded technology and treated at the temperature between the melting points of Al and Ti. The microstructure evolution and growth mechanism of the Al-Ti DRZ were investigated. Th...Al-Ti diffusion couples were made by embedded technology and treated at the temperature between the melting points of Al and Ti. The microstructure evolution and growth mechanism of the Al-Ti DRZ were investigated. The result shows that the DRZ, the mixture of TiAl3 and Al, grows layer by layer along their chemical equilibrium zone. In the course, the growth interface moves toward the aluminum side. TiAl3 is the only new phase which forms earliest in the course of heat-treatment. The growth mechanism of the DRZ changes after the phase transition of titanium. Before the phase transition of titanium, the growth of the DRZ is controlled by the dissolution speed of the titanium to the molten aluminum, while after the phase transition of titanium, the growth is controlled by the chemical reaction speed of Al and Ti atoms, and consequently, its growth rate is greatly increased.展开更多
The formation of periodic layered structure in Ni3Si/Zn diffusion couples with Zn in vapor or liquid state was investigated by SEM-EDS, FESEM and XRD. The results show that the diffusion path in solid-liquid reaction ...The formation of periodic layered structure in Ni3Si/Zn diffusion couples with Zn in vapor or liquid state was investigated by SEM-EDS, FESEM and XRD. The results show that the diffusion path in solid-liquid reaction is Ni3Si/(T+γ)/γ/…T/γ/Ni4Zn12Si3/γ/…Ni4Zn12Si3/γ/Ni4Zn12Si3/δ…/Ni4Zn12Si3/δ/liquid-Zn, and the diffusion path in solid-vapor reaction is Ni3Si/θ/(T+γ)/γ/…/T/γ/…T/γ/vapor-Zn. With increasing Zn diffusion flux, the diffusion reaction path moves toward the Zn-rich direction, and the distance from the Ni3Si substrate to the periodic layer pair nearest to the interface decreases. In the initial stage of both reactions,γphase nucleates and grows within T matrix phase at first, and then conjuncts together to form a band to reduce the surface energy. Based on the experimental results and diffusion kinetics analysis, the microstructure differences were compared and the formation mechanism of the periodic layered structure in Ni3Si/Zn system was discussed.展开更多
Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investig...Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investigated in detail. The results show that cladding billets with different clad-ratios were fabricated successfully. Si and Mn elements diffused across the bonding interface and formed diffusion layer. With the increase of clad-layer thickness, the interfacial region transforms from semisolid-solid state to liquid-solid state and the diffusion layer increased from 10 to 25 μm. The hardness at interface is higher than that of AA3003 side but lower than that of the other side. The bonding strength increased with the clad-layer thickness, attributing to solution strengthening due to elements diffusion. The cladding billets were extruded into clad pipe by indirect extrusion process after homogenization. The clad pipe remained the interfacial characteristics of as-cast cladding billet and the heredity of clad-ratio during deformation was testified.展开更多
In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface betwee...In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.展开更多
Based on the diffusion channel,the influence of Si content on the microstructure evolution of iron-based hot-dip Al-χSi coating was analyzed(χ=0,1.5 wt%,3.0 wt% and 7.0 wt%).The results show that the introduction of...Based on the diffusion channel,the influence of Si content on the microstructure evolution of iron-based hot-dip Al-χSi coating was analyzed(χ=0,1.5 wt%,3.0 wt% and 7.0 wt%).The results show that the introduction of Si makes the reaction interface change from the lingual-tooth interface of hot-dip Al to the flat interface of hot-dip Al-Si.It also reduces the thickness of the alloy layer in the coating,especially the Fe_(2)Al_(5) layer.When the Si content is 1.5 wt%or 3.0 wt%,the diffusion channel crosses the conjugate line of the two-phase region(FeAl_(3)+liquid phase)into the FeAl_(3) single-phase region,and then moves to the region with higher Si content.Next,the diffusion channel cuts off the conjugate line of FeAl_(3)phase,τ_(1)/τ_(9) phase,and Fe_(2)Al_(5)phase,which promotes the form ofτ_(1)/τ_(9) phase.The formedτ_(1)/τ_(9) phase inhibits the diffusion between Fe and Al atoms.When the Si content is 7.0 wt%,the diffusion channel passes through the two-phase region(liquid phase+τ_(5))and enters theτ_(5) single-phase region.The form ofτ_(5) single-phase region has a strong inhibitory effect on the interatomic diffusion of Fe and Al,thereby reducing the thickness of the coating,especially the Fe_(2)Al_(5)layer.展开更多
文摘The influence of Mo and ZrO_(2)nanoparticles addition on the interfacial properties and shear strength of Sn58Bi solder joint was investigated.The interfacial microstructures of Sn58Bi/Cu,Sn58Bi+Mo/Cu and Sn58Bi+ZrO_(2)/Cu solder joints were analysed using a scanning electron microscope(SEM)coupled with energy dispersive X-ray(EDX)and the X-ray diffraction(XRD).Intermetallic compounds(IMCs)of MoSn_(2)are detected in the Sn58Bi+Mo/Cu solder joint,while SnZr,Zr_(5)Sn_(3),ZrCu and ZrSn_(2)are detected in Sn58Bi+ZrO_(2)/Cu solder joint.IMC layers for both composite solders comprise of Cu_(6)Sn_(5) and Cu_(3)Sn.The SEM images of these layers were used to measure the IMC layer’s thickness.The average IMC layer’s thickness is 1.4431μm for Sn58Bi+Mo/Cu and 0.9112μm for Sn58Bi+ZrO_(2)/Cu solder joints.Shear strength of the solder joints was investigated via the single shear lap test method.The average maximum load and shear stress of the Sn58Bi+Mo/Cu and Sn58Bi+ZrO_(2)/Cu solder joints are increased by 33%and 69%,respectively,as compared to those of the Sn58Bi/Cu solder joint.By comparing both composite solder joints,the latter prevails better as adding smaller sized ZrO_(2)nanoparticles improves the interfacial properties granting a stronger solder joint.
基金Project (ZR2011EL023) supported by the Natural Science Foundation of Shandong Province,ChinaProject (12CX04057A) supported by the Fundamental Research Funds for the Central Universities,China
文摘Al-Ti diffusion couples were made by embedded technology and treated at the temperature between the melting points of Al and Ti. The microstructure evolution and growth mechanism of the Al-Ti DRZ were investigated. The result shows that the DRZ, the mixture of TiAl3 and Al, grows layer by layer along their chemical equilibrium zone. In the course, the growth interface moves toward the aluminum side. TiAl3 is the only new phase which forms earliest in the course of heat-treatment. The growth mechanism of the DRZ changes after the phase transition of titanium. Before the phase transition of titanium, the growth of the DRZ is controlled by the dissolution speed of the titanium to the molten aluminum, while after the phase transition of titanium, the growth is controlled by the chemical reaction speed of Al and Ti atoms, and consequently, its growth rate is greatly increased.
基金Projects(51271040,51171031)supported by the National Natural Science Foundation of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The formation of periodic layered structure in Ni3Si/Zn diffusion couples with Zn in vapor or liquid state was investigated by SEM-EDS, FESEM and XRD. The results show that the diffusion path in solid-liquid reaction is Ni3Si/(T+γ)/γ/…T/γ/Ni4Zn12Si3/γ/…Ni4Zn12Si3/γ/Ni4Zn12Si3/δ…/Ni4Zn12Si3/δ/liquid-Zn, and the diffusion path in solid-vapor reaction is Ni3Si/θ/(T+γ)/γ/…/T/γ/…T/γ/vapor-Zn. With increasing Zn diffusion flux, the diffusion reaction path moves toward the Zn-rich direction, and the distance from the Ni3Si substrate to the periodic layer pair nearest to the interface decreases. In the initial stage of both reactions,γphase nucleates and grows within T matrix phase at first, and then conjuncts together to form a band to reduce the surface energy. Based on the experimental results and diffusion kinetics analysis, the microstructure differences were compared and the formation mechanism of the periodic layered structure in Ni3Si/Zn system was discussed.
基金Project(2015B090926013)supported by the Science and Technology Program of Guangdong Province,ChinaProject(20170540307)supported by the Natural Science Foundation of Liaoning Province,China
文摘Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investigated in detail. The results show that cladding billets with different clad-ratios were fabricated successfully. Si and Mn elements diffused across the bonding interface and formed diffusion layer. With the increase of clad-layer thickness, the interfacial region transforms from semisolid-solid state to liquid-solid state and the diffusion layer increased from 10 to 25 μm. The hardness at interface is higher than that of AA3003 side but lower than that of the other side. The bonding strength increased with the clad-layer thickness, attributing to solution strengthening due to elements diffusion. The cladding billets were extruded into clad pipe by indirect extrusion process after homogenization. The clad pipe remained the interfacial characteristics of as-cast cladding billet and the heredity of clad-ratio during deformation was testified.
基金Project supported by the New Staff Research Start-up Fund and the Innovation Fund(School of Materials Science and Engineering) of Southwest Petroleum University,China
文摘In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.
基金Projects(51971039,51671037)supported by the National Natural Science Foundation of ChinaProject(19KJA530001)supported by the Natural Science Research Project of Higher Education of Jiangsu,ChinaProject(KYCX21_2868)supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China。
文摘Based on the diffusion channel,the influence of Si content on the microstructure evolution of iron-based hot-dip Al-χSi coating was analyzed(χ=0,1.5 wt%,3.0 wt% and 7.0 wt%).The results show that the introduction of Si makes the reaction interface change from the lingual-tooth interface of hot-dip Al to the flat interface of hot-dip Al-Si.It also reduces the thickness of the alloy layer in the coating,especially the Fe_(2)Al_(5) layer.When the Si content is 1.5 wt%or 3.0 wt%,the diffusion channel crosses the conjugate line of the two-phase region(FeAl_(3)+liquid phase)into the FeAl_(3) single-phase region,and then moves to the region with higher Si content.Next,the diffusion channel cuts off the conjugate line of FeAl_(3)phase,τ_(1)/τ_(9) phase,and Fe_(2)Al_(5)phase,which promotes the form ofτ_(1)/τ_(9) phase.The formedτ_(1)/τ_(9) phase inhibits the diffusion between Fe and Al atoms.When the Si content is 7.0 wt%,the diffusion channel passes through the two-phase region(liquid phase+τ_(5))and enters theτ_(5) single-phase region.The form ofτ_(5) single-phase region has a strong inhibitory effect on the interatomic diffusion of Fe and Al,thereby reducing the thickness of the coating,especially the Fe_(2)Al_(5)layer.