Archive

  • 2010 Volume 0 Issue 10
    Published: 20 October 2010
      

  • Select all
    |
  • XU Zhiwu, YAN Jiuchun, ZHONG Li, YANG Shiqin
    2010, 0(10): 1-4,8.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    XU Zhiwu, YAN Jiuchun, ZHONG Li, YANG Shiqin. Filling and Wetting Behaviors of Liquid Filler Metal in the Process of Ultrasonic Soldering of Aluminum Alloy[J]. Journal of Materials Engineering, 2010, 0(10): 1-4,8.

    Filling of liquid filler metal into the joint clearance of 6061Al and 2024Al alloys under the action of ultrasonic vibration was investigated.The effects of heating temperature and joint clearance value on the filling process were concerned with.The results show that the filling of liquid filler metal under the action of ultrasonic vibration is quite different from that induced by the traditional capillary effect.The non-wetting liquid filler fills rapidly into the joint clearance once the ultrasonic vibration is applied and the morphology of the liquid-gas interface appears convex at the initiate stage.With the development of the filling process,the filling velocity decreases and the wetting between the liquid filler and the base metal at the filling front is improved,giving rise of the transition of the morphology of the liquid-gas interface from convex to concave.Heating temperature shows no obvious influence on the filling process.The filling length decreases and the morphology of liquid-gas interface tend to change with the joint clearance increase.
  • YAN Jianfeng, ZOU Guisheng, LI Jian, WU Aiping
    2010, 0(10): 5-8.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    YAN Jianfeng, ZOU Guisheng, LI Jian, WU Aiping. Study on the Sintering Characteristics and Application in Cu Bulk Bonding of Ag-nanoparticle Paste[J]. Journal of Materials Engineering, 2010, 0(10): 5-8.

    Ag nanoparticle paste with size distribution of 20-80nm was prepared by chemical reduction reaction.Each nanoparticle was covered with a thin organic shell which can prevent its aggregation.Micro-structural evolution was observed using scanning electron microscope(SEM).The results suggested that the sintered Ag layer was a connected porous-structure after sintered for 30min at 200℃.At sintering temperature above 250℃,some Ag grains grew up obviously.The sintering-bonding with Ag nanoparticle paste of silver plated pure coppers was performed at 250℃ under 10MPa.The joint had a shear strength of 39MPa.The microscopic analysis of sintered Ag layers from the sheared fracture appearance of joints showed that sintered Ag layer had a dense structure.There was no obvious trace of plastic distortion at the low magnification SEM images of fracture-appearance of joints.However,at high magnification SEM images displayed the dimple structure feature which is typical microstructure at fracture surface of ductile material.
  • LI Hongmei, SUN Daqian, WANG Wenquan, HAN Yaowu, DONG Peng
    2010, 0(10): 9-12,26.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LI Hongmei, SUN Daqian, WANG Wenquan, HAN Yaowu, DONG Peng. Laser Welding of TiNi Shape Memory Alloy Using Pure Cu as Interlayer[J]. Journal of Materials Engineering, 2010, 0(10): 9-12,26.

    YAG laser welding was used to join TiNi shape memory alloy thin wires with pure Cu as interlayer.The microstructural charactertics were investigated by means of optical microscopy,scanning electronic microscopy and micro-XRD et al.The tensile and bending tests were carried out to examine the mechanical properties and shape memory effect of the joint.Experimental results show that the joint has the heterogeneous microstructure and element distribution.B2,B19,Ti3Ni4,Cu solid solution and the intermetallic compounds,such as CuTi,Cu4Ti3,Cu3Ti2,Cu3Ti2,Cu3Ti were detected in fusion zone by XRD test.The laser-welded joint exhibits the ultimate strength of 489-536 MPa with ductile-brittle mixed fracture mode,and the shape recovery ratio reaches to 99%.
  • HE Peng, L� Xiaochun, ZHANG Binbin, MA Xin, QIAN Yiyu
    2010, 0(10): 13-17,31.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    HE Peng, L� Xiaochun, ZHANG Binbin, MA Xin, QIAN Yiyu. Effect of Alloy Element on Microstructure and Impact Toughness of Sn-57Bi Lead-free Solders[J]. Journal of Materials Engineering, 2010, 0(10): 13-17,31.

    The effect of Ag,Ge,Cu,Sb,Zn,Ce,P and Ni inclusions on melting temperature,wettability,impact toughness and microstructure of 43Sn-57Bi lead-free solders were investigated.The result showed that those inclusions had little influence on melting temperature of the solders.Addition of P,Ni resulted in the appearance of Bi,which decreased the performance of solders.Ag3Sn and zinc rich phase could increase the performance when the shape was appropriate.Add Ag,Ge,Zn,Cu solely could improve the solder's ductility,while Sb,Ce,P,Ni could decrease the ductility.Yield strength of the solders and shear strength of the joint could improve with the addition of Ag,Ge.The improvement effort of 43Sn-Bi-1Ge-1Ag was the best in the solders with several inclusions.
  • ZHANG Keke, HAN Lijuan, WANG Yaoli, ZHANG Xin, ZHU Yaomin
    2010, 0(10): 18-21,37.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    ZHANG Keke, HAN Lijuan, WANG Yaoli, ZHANG Xin, ZHU Yaomin. Research of Intermetallic Compounds at Interface of Sn2.5Ag0.7CuxRE Solder Joints During Aging[J]. Journal of Materials Engineering, 2010, 0(10): 18-21,37.

    The intermetallic compound(IMC) and its growing behavior of Sn2.5Ag0.7CuxRE/Cu solder joint were investigated in the mediator of molybdenum sulfide by means of scanning electronic microscope and X-ray diffraction during aging.The results show that the Cu6Sn5 morphology of solder joint interface can be changed from initial wavy-like to scallop-like,then to shape-layer.The thickness of Cu6Sn5 and Cu3Sn IMC at the solder joint interface and the square root of aging time is coincidence with the liner relation,the growing activation energy of Cu6Sn5 is smaller and its coefficient of growth is larger than those of Cu3Sn.The shear strength of the solder joint is the highest with adding 0.1%(mass fraction) RE in the Sn2.5Ag0.7Cu solder alloys,and the Cu6Sn5 and Cu3Sn at solder joint interface have the largest growing activation energy which is separately 81.74 kJ/mol and 92.25 kJ/mol.
  • LIU Liangqi, XU Jinhua, CHEN Sheng, MA Xin, ZHANG Xinping
    2010, 0(10): 22-26.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LIU Liangqi, XU Jinhua, CHEN Sheng, MA Xin, ZHANG Xinping. Effect of Ag Addition on the Properties of Sn-1.5Zn Based Alloys for Soldering Aluminum[J]. Journal of Materials Engineering, 2010, 0(10): 22-26.

    The influence of Ag addition on the melting characteristics,microstructures,wettability and corrosion-resistance of the Sn-1.5Zn based alloys for soldering aluminum was investigated.The experimental results show that Ag addition in Sn-1.5Zn based solder alloys decreases the melting point range and refines the microstructures;furthermore,the wetting balance test results manifest that the addition of Ag into Sn-1.5Zn increases the maximum wetting force(Fmax) of the solders,while increasing the wetting time t0;finally,it has been shown that the joints soldered by the Ag-added Sn-1.5Zn based alloys exhibit the increased corrosion resistance in 3%(mass fraction) NaCl solution.
  • CHEN Bo, XIONG Huaping, CHENG Yaoyong, MAO Wei, YE Lei, LI Xiaohong
    2010, 0(10): 27-31.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    CHEN Bo, XIONG Huaping, CHENG Yaoyong, MAO Wei, YE Lei, LI Xiaohong. Microstructure and Strength of Cf/SiC Joints with Ag-Cu-Ti Brazing Fillers[J]. Journal of Materials Engineering, 2010, 0(10): 27-31.

    The vacuum brazing of Cf/SiC ceramic matrix composite was studied with Ag-35.5Cu-1.8Ti and Ag-27.4Cu-4.4Ti brazing fillers at 880℃ for 10min and the sound joints were achieved.The SEM,XEDS and XRD analyzed results indicated that the reaction layers of two kinds of joints were visible in the brazing seams near the Cf/SiC matrix.Element Ti distributed at the reaction layers and reacted with C,forming TiC phase.Ti-Si phase was not detected in the reaction layers.The typical eutectic microstructure was formed in the central part of the joints.The room-temperature three-point bend strengths of the Cf/SiC joints brazed with Ag-35.5Cu-1.8Ti and Ag-27.4Cu-4.4Ti are 132.5 MPa and 159.5MPa respectively.The activity of Ti in the brazing fillers is the critical factor to the mechanical property of the joints,that is,the joints strength improves with the increase of the activity.
  • LANG Bo, HOU Jinbao, WU Song
    2010, 0(10): 32-37.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LANG Bo, HOU Jinbao, WU Song. Transient Liquid Phase Diffusion Bonding of DD32 Single Crystal Superalloy[J]. Journal of Materials Engineering, 2010, 0(10): 32-37.

    Microstructure of transient liquid phase(TLP) diffusion bonding DD32 single crystal superalloy joint,microstructural evolution of the parent material during TLP diffusion bonding and stress-rupture has been investigated using scanning electron microscopy(SEM) and energy-dispersive spectrum(EDS) for improving mechanical properties of joint.The results show that the joint contains bonding zone and parent material zone.The diffusion zone is hardly visible.The bonding zone contains isothermal solidification zone and residual liquid zone.Effect of TLP diffusion bonding on the microstructure of the parent material is very important.Therefore,the joints needed postweld heat treatment.Besides,N-type rafts were formed in the parent material during stress-rupture.The mechanical properties of the joint could be effectively improved by restraining formation of grain boundary in the TLP diffusion bonding joint.
  • XIAO Hui, LI Xiaoyan, LI Fenghui
    2010, 0(10): 38-42.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    XIAO Hui, LI Xiaoyan, LI Fenghui. Growth Kinetic of Intermetallic Compounds and Failure Behavior for SnAgCu/Cu Solder Joints Subjected to Thermal Cycling[J]. Journal of Materials Engineering, 2010, 0(10): 38-42.

    The growth kinetic of intermetallic compounds(IMCs) and fatigue failure behavior of SnAgCu/Cu solder joints subjected to thermal cycling have been investigated.An equivalent IMC growth equation for thermal cycling and a heterogeneous model for solder joint interface were proposed,and the finite element(FEM) simulation was applied to analyze the stress/strain field distribution on solder joint interface as well as the failure mode of solder joints subjected to thermal cycling.The results show that the lower the cryogenic temperature limit of the thermal cycling,the lower the fatigue life of the solder joint.Failure mode of solder joints exhibits solder fatigue failure with failure site close to solder/IMC interface.The thicker the IMC layer,the more accumulated plastic work density in solder joint,as a result,the solder joint with a thicker IMC layer is more prone to failure.
  • LIU Jie, QIU Xiaoming, WANG Hongying, SUN Daqian, YAO Hanwei, HAN Xiuhong
    2010, 0(10): 43-47.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LIU Jie, QIU Xiaoming, WANG Hongying, SUN Daqian, YAO Hanwei, HAN Xiuhong. Reaction Mechanism of Ni-Cr/Ti/Porcelain Interface[J]. Journal of Materials Engineering, 2010, 0(10): 43-47.

    Ti film was sputtered on Ni-Cr alloy substrate with magnetron sputtering and so it acted as an interlayer for Ni-Cr/porcelain interface.Microstructure,products category,distribution and reaction mechanism of bonding interface of Ni-Cr/Ti/porcelain have been investigated.Experimental results showed that the Ni-Cr/Ti/porcelain interface was very complicated and the interface has new phase composition with Ti2Ni,AlTi3,TiO2,SnCr0.14OX,NiCr2O4 and Cr2O3.During the high temperature firing,AlTi3 compound was produced by the reaction between Ti and Al2O3 in porcelain,stable Ti2Ni compound between Ti and Ni,and TiO2 produced by the displacement reaction between Ti and SnO2,SiO2,etc,then TiO2 reacts with the oxides in porcelain and exits with sosoloid mode.Ti interlayer reacts with porcelain as well as Ni-Cr alloy during high temperature firing after sputtering Ti interlayer on Ni-Cr alloy surface which can realize the bond Ni-Cr alloy with porcelain.
  • LI Tianwen, GUO Wanlin, HUAI Junfeng
    2010, 0(10): 48-52.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LI Tianwen, GUO Wanlin, HUAI Junfeng. Brazing of Superalloy GH586 with Nickel-base Filler Metals[J]. Journal of Materials Engineering, 2010, 0(10): 48-52.

    The superalloy GH586 was brazed with BNi82CrSiB and BNi81CrB amorphous foils for different holding time.The joint strength was tested.The microstructure and fracture surface were analyzed by SEM and EDS.The results show that,when prolonging the brazing time(60min),alloy elements distributed more uniformly in the brazed seam and the diffusion area,and the joint strength not only at room temperature but also at 930℃ was increased.Also the joint tensile properties were increased by adjusting chemical compositions of nickel base filler alloys,and the joint strength at 930℃ was increased 22.5%.The joint fracture occurred at the base metal near the brazed seam,with an intergranular fracture mode.The influence of elements Si and B on the joint microstructures and properties was also discussed.
  • WEI Guoqiang, WAN Zhonghua, ZHAO Siyong, ZHANG Yupeng, LIU Fengmei
    2010, 0(10): 53-56.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    WEI Guoqiang, WAN Zhonghua, ZHAO Siyong, ZHANG Yupeng, LIU Fengmei. Investigations on Melting Property,Wettability and Mechanical Property of Sn-XAg-0.5Cu Lead-free Solder Alloys[J]. Journal of Materials Engineering, 2010, 0(10): 53-56.

    The melting property,wettability and mechanical property of Sn-XAg-0.5Cu(X=0.1-3.0) lead-free solder alloys were investigated by differential scanning calorimetry(DSC),wetting balance technique,sessile drop method and tensile test.The DSC revealed that the endothermic onset temperature on heating appeared at about 217.3℃ for the all solder alloys.With increasing the Ag content of the solder alloys,the melting temperature ranges of the solders became narrow.It was also shown by the wetting balance and sessile drop experiments that the wettability remarkably increased with the Ag content increased,and then with Ag content farther increased,the wettability were kept constant approximately.The threshold value of the Ag content was 1.0%(mass fraction/%,the same below),which considerably effected on wetting-spreading areas and wetting forces(or wetting time).Meanwhile,when Ag content is between 0.5% and 3.0%,the specific elongation of solders decreased with the Ag content increased,while the tensile strength and 0.2% yield stresses increased,too.
  • GAO Yong, XIA Zhidong, CUI Yingya
    2010, 0(10): 57-60.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    GAO Yong, XIA Zhidong, CUI Yingya. Microstructure of FeCrAl Alloy Vacuum Brazing with Ni82CrSiB Filler Metal[J]. Journal of Materials Engineering, 2010, 0(10): 57-60.

    The FeCrAl foil was coiled into a round porous structure and it was brazed in vacuum at 1070℃ for 10min using the BNi82CrSiB brazing foils.Results showed that there were no defects on the surface,and the sound joint was obtained,and 99%(the number of joints is about 8000) of the solder joints were connected.The microstructures were made up with Ni-based solid solution,intermetallic compounds and eutectic structure.It was shown that the interface reaction products were γ-Ni,FeNi3,AlNi3,CrB and Ni17Si3.A great number of borides were formed in the brazed joint.
  • YE Lei, XIONG Huaping, CHEN Bo, MAO Wei, CHENG Yaoyong, LI Xiaohong
    2010, 0(10): 61-64,68.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    YE Lei, XIONG Huaping, CHEN Bo, MAO Wei, CHENG Yaoyong, LI Xiaohong. Microstructures of TiAl Joints Brazed with CoFe-based and Fe-based High-temperature Filler Metals[J]. Journal of Materials Engineering, 2010, 0(10): 61-64,68.

    CoFe-based and Fe-based high-temperature filler metals were studied for the control of the excessive reaction between filler metal and TiAl base metal at high brazing temperatures.The wettability of two filler metals on TiAl was studied at 1100℃/10min and 1200℃/10min,and the vacuum brazing experiment was carried out at 1180℃ for 5min.The results showed that the contact angles of the two kinds of filler metals were about 30° at 1200℃/10min.The interfacial reactions of the two filler metals with TiAl were not as strong as that of the traditional Ni-based filler metal.Main microstructures of the joint brazed with CoFe-based filler metal were Ti3Al,TiAl,silicide and(Ti,Cr)-B phase.Furthermore,a narrow Cr-rich solid solution zone(about 10μm) was formed in the central part of the joint.The similar microstructures were formed for the joint brazed with Fe-based filler metal.But there is also a difference,for the joint brazed with Fe-based filler metal,a wider residual filler metal zone(about 40μm) was formed in its central part,and the main phase was identified to be Ferich solid solution.TiB and TiB2 phases were formed near the residual filler metal zone,and the amount of borides was much more than that of CoFe-based filler metal.
  • SHI Lei, YAN Jiuchun, HAN Yanfei, PENG Bo
    2010, 0(10): 65-68.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    SHI Lei, YAN Jiuchun, HAN Yanfei, PENG Bo. Development of a Semi-solid Zn-Al Alloy Filler Metal with Globular Grains[J]. Journal of Materials Engineering, 2010, 0(10): 65-68.

    The Zn-Al alloy with globular grains has been fabricated by smelting,pouring and isothermal heat treating;and the relationship between solid volume fraction and temperature,compressive deformation behavior and braze ability to serve as filler metal for the Zn-Al alloy in semi-solid state have been investigated by the experiments of remelting,isothermal compressing and vibration assisted semi-solid brazing.The results indicate that: the semi-solid Zn-Al alloy has an intensive deformation resistance during compression;for serving the Zn-Al alloy as filler metal,the fluctuation of solid fraction for filler metal with temperature can be controlled in the range of(64±5)% during brazing process,and the oxide layer is disrupted thoroughly on the interface of brazed joint.
  • LI Jing, HOU Jinbao, WU Song
    2010, 0(10): 69-72.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LI Jing, HOU Jinbao, WU Song. Study the Evaporating Controlled of Near Surface Element in TLP Diffusing Bonded[J]. Journal of Materials Engineering, 2010, 0(10): 69-72.

    For controlling the evaporating of near surface element in TLP diffusing bonded the effect of joint microstructure and Cr content was tested with doing some partial pressure experiments with argon gas in IC10 alloy TLP diffusing bonded.The results indicated that TLP diffusing bonded with vacuum full of argon gas can control the surface element Cr evaporating,the evaporating thickness was 4μm.The problem of element Cr evaporating in TLP bonded was controlled effectively.Vacuum full of argon gas after holding 20 minute,there was no bad effect to the joint microstructure and property.Heat treatment after bonding can increase the bonding intensity,recover the microstructure.After adding coating and through diffusion treating,the depleted Cr layer disappear.
  • LI Zhuoran, WANG Zhengzheng, WU Guangdong, ZHU Xiaozhi
    2010, 0(10): 73-76.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LI Zhuoran, WANG Zhengzheng, WU Guangdong, ZHU Xiaozhi. The Microstructure and Mechanical Property of the ZrB2-based Ultra-high-temperature Ceramic Composites Joints[J]. Journal of Materials Engineering, 2010, 0(10): 73-76.

    ZrB2-SiC ceramic composites were brazed by using Ti-Zr-Ni-Cu active filler in a vacuum furnace.The microstructure and mechanical property of the joints were analyzed by means of SEM,EDS and XRD.The results showed that the reaction products of the ZrB2-SiC ceramic composites joint brazed with Ti-Zr-Ni-Cu active filler were TiC,ZrC,Ti5Si3,Zr2Si,Zr(s,s) and(Ti,Zr)2(Ni,Cu).With the increase of the brazing temperature and the holding time,the thickness of the Zr(s,s) was growing gradually;the volume and quantity of Ti5Si3+Zr2Si were also growing gradually and it might grow into the center of the joint;the volume and quantity of TiC+ZrC were obviously growing and it mostly grew through the joint.When the brazing temperature is 920℃ and the holding time is 10min,the ZrB2-based ultra-high-temperature ceramic composites joint achieves the maximum shear strength about 143.5MPa.
  • YU Zhishui, SHI Kun, YAN Zhi, LI Jun, LI Ruifeng
    2010, 0(10): 77-81.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    YU Zhishui, SHI Kun, YAN Zhi, LI Jun, LI Ruifeng. Effect of Brazing Clearance on the Vacuum Brazed Joint Microstructure of 316L Stainless Steel[J]. Journal of Materials Engineering, 2010, 0(10): 77-81.

    Vacuum brazing with nickel-based filler metal BNi2+40%BNi5 was carried out for brazing of 316L stainless steel.Microstructure of joints brazed,element distribution and micro-hardness are evaluated under different brazing clearance by optical microscope,electron probe microanalyzer and micro-hardness meter.The results show that joints brazed consists of solid solutions,eutectic structures and meshwork compounds,boron and silicon are the main compounds formed elements in joints brazed;the mounts of intermetallic compounds decreased with the decrease of the brazing clearance,the microstructure of the joints brazed is mainly solid solution when the brazing clearance is 30μm.
  • LI Yulong, JIANG Zhichao, YU Yexiao
    2010, 0(10): 82-85.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LI Yulong, JIANG Zhichao, YU Yexiao. Microstructure and Mechanical Properties of the Welding-brazed Joint for the Aluminium and Galvanized Steel Sheet[J]. Journal of Materials Engineering, 2010, 0(10): 82-85.

    For joining aluminium and galvanized steel sheet with high efficiency and quality,the 6061 aluminium sheet and SPCC galvanized steel sheet were welding-brazed using Fronius cold metal transfer(CMT) equipment.Results show that the sample can be well welded using the proposed parameters of expert system;cross-section of the joint can be divided into three zones: the Zn-rich zone,the aluminium melted zone and the reaction layer between aluminium and steel;EDS results show that the Zn-rich zone is mainly composed of Zn and Al,and the reaction phase in the reaction layer between aluminium and steel is Fe2Al5.There are flaws in the joint,such as blow holes,cold laps and eutectic shrinkage cavities.Tensile tests show the average joint strength value was up to 80MPa;hardness tests show the average hardness of the Fe2Al5 layer,the galvanized steel and the melted aluminium are HV410,HV130 and HV55,respectively.
  • HUANG Wei, ZHU Ying, HE Jing, WANG Ruijun
    2010, 0(10): 86-88,95.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    HUANG Wei, ZHU Ying, HE Jing, WANG Ruijun. Preparation and Properties of Nano-YSZ Thermal Spraying Powders[J]. Journal of Materials Engineering, 2010, 0(10): 86-88,95.

    The preparation process of nano-YSZ thermal spraying powders was investigated on the excellent performance of nano coating.The agglomerated powders were prepared by spray-drying.The flow ability,free holding density and microstructure of agglomerated powders were tested and analyzed by Hall funnel method and scanning electron microscopic respectively.The result shows that the higher solid content is,the better flow ability and free holding density of powders they will be.However,an overhigh solid content will affect the granulation results.Maintaining a solid content,flow ability of powders is better with moderate binder content.To gain the agglomerated powders of better properties,the optimum follow-up process is the plasma densification process with current 300A and voltage 40V.
  • LU Xiaochun, HE Peng, ZHANG Binbin, MA Xin, QIAN Yiyu
    2010, 0(10): 89-95.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    LU Xiaochun, HE Peng, ZHANG Binbin, MA Xin, QIAN Yiyu. Effect of Solidification Mode on Microstructure and Properties of Sn-Bi Solders[J]. Journal of Materials Engineering, 2010, 0(10): 89-95.

    Effects of different solidification modes,including of furnace cooling,air cooling,water cooling and liquid nitrogen cooling,and magnetic fields on the impact toughness and microstructure of Sn-Bi solders are studied.The results show that fast cooling and rotating magnetic fields were applied for refining the structure of the Sn-Bi solder.Although these technologies can refine the grain size,meanwhile they reduced the plasticity of the solder.For Sn-57Bi alloy fast cooling caused the segregation of Bi,and the rotating magnetic field lead to the structural heterogeneity.Both methods destroyed the strengthening mechanism of adding Ge and lead the Ag3Sn phase to become coarse.Further more,the centrifugal force of the rotating magnetic of the 43Sn-Bi-3.5Ag caused the increase of segregation.With the cooling rate increases,the toughness of Sn-57Bi eutectic solder increase firstly and then decrease due to the joint actions of structure refinement and segregation.
  • ZHOU Yuan, LI Xiaohong, MAO Wei, BI Xiaofang, XIONG Huaping, WU Xin
    2010, 0(10): 96-99.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    ZHOU Yuan, LI Xiaohong, MAO Wei, BI Xiaofang, XIONG Huaping, WU Xin. Diffusion Bonding of Titanium Alloy and Superalloy at Lower Temperature Using the Ti and Ni Thin Films as Interlayer[J]. Journal of Materials Engineering, 2010, 0(10): 96-99.

    Diffusion bonding of titanium alloy TA15 to superalloy DD6 was investigated at a lower temperature using Ti and Ni thin films as interlayer,which were deposited on the surfaces of TA15 and DD6 respectively by magnetron sputtering.X-ray diffraction analysis was carried out to test the crystal structure of films deposited on the substrate.The multicrystal structure was observed from both patterns of Ti and Ni films.The roughness of the substrate was examined by AFM.The results showed that the roughness of TA15 and DD6 substrates decreased after deposited the Ti and Ni films.Diffusion bonded joint of TA15 with DD6 has been achieved at the condition of 800℃/20MPa/2h with the interlayer of Ti and Ni films.The microstructure and composition of joint were studied by SEM and EDS.Elements Ti and Ni diffused the base metal on the other side.Several layers appeared in the joint,mainly composed of Ti2Ni and TiNi phases.
  • ZHANG Yupeng, WAN Zhonghua, XU Lei, LIU Fengmei, YANG Kaizhen
    2010, 0(10): 100-104.
    PDF ( ) Cite this article   Knowledge map   Save
    X

    ZHANG Yupeng, WAN Zhonghua, XU Lei, LIU Fengmei, YANG Kaizhen. Study on Properties of Low-silver Lead-free Solder Alloys with Alloy Element Doping[J]. Journal of Materials Engineering, 2010, 0(10): 100-104.

    Low-silver(Ag<1%,mass fraction) SAC lead-free solder alloys meet wettability and reliability problems.Effect of silver content,nickel and bismuth element additions on some key properties such as microstructures,wettability and copper dissolution property of solder alloys was investigated to seek the possible solution.The results showed that the regular change of microstructures,melting behavior and tensile property of the solder alloys was resulted by the increase of silver content;the additions of bismuth and nickel could improve the solderability(wettability) property of the alloys and lower the copper dissolution rate.It was also found that the copper dissolution rate of SAC0805BiNi solder is lower than SAC0307 and SAC305 solder alloys,and wettability is close to SAC305 alloy.The alloys with silver content between 0.3% and 1% mass percentages exhibit good ductility.Consequently,the overall performance of low cost solder alloys will be approaching to the SAC305 alloys with proper silver content and addition of alloy elements.
Submission

Founded in 1956 (monthly)

ISSN 1001-4381

CN 11-1800/TB

Sponsored by

AECC Beijing Institute of Aeronautical Materials

Hot Special Issues

Topic