6063铝合金／Ag／Ni／1Cr18Ni9Ti共晶反应钎焊研究

研究采用Ni-Ag复合镀层,在特定的工艺参数条件下,对6063铝合金与1Cr18Ni9Ti进行了共晶反应钎焊试验,初步分析探讨了工艺参数对钎缝微观组织结构反形态的影响和Ni层的阻隔作用.对钎缝的界面作扫描电镜和能谱分析发现,镀层与母材等各界面连接紧密,特别是钎缝与母材之间没有生成脆性Al-Fe金属间化合物.结果表明:在钎焊温度580℃,共晶反应钎焊6063铝合金1Cr18Ni9Ti,保温5 min,钎缝成形较好;面心立方结构Ni/Ag电刷镀层能有效地阻挡Al,Fe等原子扩散.     

铝合金/不锈钢高频感应钎焊接头结构与性能研究

采用自炼的Al-Si-Cu-RE钎料进行高频感应钎焊,实现了LF21铝合金与1Cr18Ni9Ti不锈钢的连接,利用电子万能试验机进行了钎焊接头剪切试验,利用SEM,EDS等手段对钎焊接头的微观组织进行研究和分析.微观结构分析表明,钎焊接头的显微组织由α(Al)-θ (CuAl2)共晶组成,高频感应快速加热避免了钎缝中Fe-Al金属间化合物的生成,且由于钎料中添加了RE元素,CuAl2相为均匀分布的枝状晶,Si相经变质处理细小分散;Al-Si-Cu-RE钎料与LF21铝合金反应良好,界面过渡均匀,钎缝与1Cr18Ni9Ti不锈钢之间有明显的分界,剪切试验表明接头抗剪强度达95 MPa.     

Al/Fe异种金属钎焊接头组织与力学性能研究

采用Al-7Si-20Cu钎料在真空钎焊条件下(不添加钎剂)对1060铝合金与Q235钢(镀Ni与不镀Ni)进行钎焊试验,研究了钎焊接头的显微组织及力学性能。研究结果表明,570℃钎焊5 min时,Fe表面不镀Ni时,Fe侧界面处生成厚度较大的Fe_2A_(l5)和FeAl_3脆性化合物,接头抗剪切强度仅为40 MPa。当Fe表面镀Ni后,Ni层的存在抑制了脆性Fe-Al化合物的形成,Fe侧界面生成Ni_2Al_3和NiAl_3化合物层,接头的剪切强度显著提高。延长钎焊时间,Ni_2Al_3层变薄,Ni Al3层增厚,接头剪切强度提高。当钎焊时间继续增加,Ni层消失,再次生成Fe-Al化合物,接头剪切强度降低。     

采用改进BNi-7钎料钎焊316L不锈钢

采用改进BNi-7钎料钎焊316L不锈钢,钎缝间隙为100μm,研究了Cu粉添加量、钎焊温度对接头组织及力学性能的影响。结果显示,采用BNi-7+x%Cu进行连接时,接头主要由不锈钢/钎料界面的Ni(Fe,Cr,Cu)固溶体和钎缝中心的Ni(Fe,Cr,Cu)-CrNiP共晶组织和Ni3P-Ni(Fe,Cr,Cu)共晶组织组成。钎缝中心Ni(Fe,Cr,Cu)-CrNiP共晶组织中分布的Ni(Fe,Cr,Cu)韧性相使脆性磷化物弥散分布;随着Cu添加量和钎焊温度的增加,钎缝中心的脆性化合物含量降低。当钎焊温度为980℃,Cu添加量为9%时,接头的抗剪强度最大为118 MPa。     

铝合金与不锈钢接触反应钎焊接头微观组织分析

采用Ag-Ni复合镀层,在钎焊温度580℃,保温时间1～20min的条件下,对6063铝合金与1Cr18Ni9Ti不锈钢进行了接触反应钎焊试验,初步分析了接头的微观组织及镀Ni层的作用效果.结果表明,在钎焊时间较短时,钎缝主要由Al(Ag)固溶体与Ag-Al化合物构成;钎焊时间超过20min,Ag-Al化合物含量显著增加,镀Ni层对防止生成Al-Fe脆性金属间化合物的作用效果减弱.     

铝/镀银层/钢的扩散钎焊及界面化合物的生长行为

采用扩散钎焊方法对6063铝合金/镀银层/1Cr18Ni9Ti不锈钢进行焊接,探讨焊接界面金属间化合物的生长行为。结果表明:钎缝中靠近不锈钢一侧为Fe-Al金属间化合物层,靠近铝合金一侧主要是Ag(Al)固溶体,中心区域由Ag-Al化合物和Ag(Al)固溶体混合而成;随着低温扩散保温时间的延长,化合物层厚度随之增加,Ag在铝合金一侧富集出现晶界渗透现象;钎缝中首先产生Ag-Al金属间化合物,之后共晶液相中的Al原子穿越Ag-Al金属间化合物层和残余镀银层扩散至不锈钢一侧,与Fe原子生成Fe-Al金属间化合物;在任意给定的扩散钎焊低条件下,可以对化合物层厚度进行初步估算。     

镀铜/镍烧结钕铁硼永磁体与DP1180钢钎焊接头的组织与性能

采用Zn-6Sn-5Bi钎料对镀Cu/Ni的烧结NdFeB永磁体和DP1180钢进行钎焊连接,对比分析了2种镀层条件下钎焊接头的微观组织和力学性能。结果表明,对于镀Cu的烧结NdFeB永磁体和DP1180钢的钎焊接头,Cu在钎料中扩散并与Zn、Fe反应生成脆性金属间化合物,导致钎缝中出现裂纹和孔洞。与无镀层时的烧结NdFeB永磁体和DP1180钢的钎焊接头相比,接头的剪切强度由61.9 MPa降低至52.3 MPa;对于镀Ni的烧结NdFeB永磁体和DP1180钢的钎焊接头,Ni集中分布在NdFeB一侧的界面处,并且由于Sn和Bi的扩散形成了不同的扩散层,其剪切强度提高至78.1 MPa。     

TiAl/Ni基合金反应钎焊接头的微观组织及剪切强度(英文)

以Ti为中间层,对TiAl基金属间化合物与Ni基高温合金进行反应钎焊连接,研究反应钎焊接头的界面微观结构及剪切强度。通过实验发现,熔融中间层与两侧母材反应剧烈,生成连续的界面反应层。典型的界面微观结构为GH99/(Ni,Cr)ss(γ)/TiNi(β2)+TiNi2Al(τ4)+Ti2Ni(δ)/δ+Ti3Al(α2)+Al3NiTi2(τ3)/α2+τ3/TiAl。当钎焊温度为1000°C,保温时间10min时,所得接头的剪切强度最高为258MPa。进一步升高钎焊温度或延长保温时间,会引起钎缝组织中组成相粗化和脆性金属间化合物层的生成,从而导致接头剪切强度的降低。     

Mo-Cu合金与1Cr18Ni9Ti不锈钢真空钎焊接头的组织性能

采用Ag-Cu-Ti钎料,控制钎焊温度为910℃,保温时间为20 min,可以实现Mo-Cu合金与1Cr1 8Ni9Ti不锈钢的真空钎焊,接头抗剪强度为75 MPa.采用扫描电镜、能谱分析仪和显微硬度计对Mo-Cu/1 Cr18 Ni9Ti接头组织特征及性能进行分析.结果表明,钎焊接头靠近1Cr18Ni9Ti钢一侧,主要形成Ag-Cu共晶组织和少量的TiC相;靠近Mo-Cu合金一侧,Ag,Cu元素在合金与钎缝间相向扩散,共晶组织消失,以富铜相为主.钎缝的显微硬度明显低于Mo-Cu合金和1Cr18Ni9Ti不锈钢母材,无脆性化合物生成,剪切断口呈现剪切韧窝的形貌特征.     

SnCu钎料合金镀层钎焊连接机理及界面反应

通过在LD31铝合金表面电刷镀Ni,Cu后再沉积SnCu钎料合金镀层的钎焊实验,研究了钎料镀层的连接机理及界面反应,改进了可降低Ni层应力的电刷镀镀Ni液的配方,开发出适合镀层钎焊的SnCu钎料合金镀液,钎焊时钎料润湿为附着润湿,研究了在300℃钎焊时焊缝界面金属间化合物的生长规律,结果表明：焊缝中Cu-SnCu界面处生成了球状和棒状的Cu6Sn5金属间化合物;拉伸时焊缝主要沿着SnCu金属间化合物和富Sn相之间的界面断裂。     

铝和不锈钢的电刷镀过渡层钎焊

采用电刷镀镍／铜过渡层的方法,研究了铝和不锈钢的钎焊,使用本工艺较好地实现了两者的连接。     

Cu基钎料MIG钎焊接头断裂行为分析

研究用Cu3SilMn钎料、Cu10Mn6Ni钎料分别MIG钎焊镀锌Q235钢板及1Cr18Ni9Ti不锈钢板。试验结果表明,在钎料／母材界面分别存在Si、Mn富集带,经XRD分析Si是以Fe2Si相形式存在,而Mn是以固溶体形式存在;用Cu3SilMn、Cu10Mn6Ni钎料钎焊镀锌Q235钢板接头抗拉强度试样均断在母材,抗拉强度为308．2－308．7MPa,钎焊1Cr18Ni9Ti不锈钢板,拉伸均断在钎缝,其抗拉强度分别是331．5MPa、423．6MPa;拉伸断口分析发现,断裂起裂点在搭接钎缝的根部,主要是母材成分与少量的钎料成分混合、溶解而成,是脆性断口;止裂点在钎缝金属中（Cu3SilMn钎料）或在近界面上（Cu10Mn6Ni钎料）,是塑性断口。     

铝合金/Cu/不锈钢接触反应钎焊及中间层溶解行为(英文)

以Cu作为接触反应材料连接6063铝合金与1Cr18Ni9Ti不锈钢,探讨焊接工艺参数对接头组织的影响规律,分析中间反应层Cu的溶解特性结果表明:在1Cr18Ni9Ti不锈钢一侧界面反应层由Fe2Al5、FeAl3金属间化合物和Cu-Al金属间化合物构成,与之相邻区域主要含Cu-Al金属间化合物,焊缝组织由Al-Cu共晶及大块状的Al固溶体组成;随着保温时间的延长,焊缝组织最为显著的变化是在1Cr18Ni9Ti不锈钢一侧界面的金属间化合物层厚度增加,共晶组织宽度逐渐减小;中间反应层Cu的溶解速度非常迅速,是以秒为计量单位的快速过程,厚度为10μm的Cu溶解时间仅为0.47s。     

预镀层不锈钢/铝异种金属高频感应钎焊接头界面及力学性能分析

文中通过热浸镀一层纯铝到不锈钢表面,再对0Cr18Ni9不锈钢和LF21铝合金采用高频感应钎焊.当热浸镀时间从10 s增加到50 s时,镀层厚度从7 μm增加到20 μm,反应层由FeAl₃向Fe₂Al₅发生转变.在热浸镀温度为750℃,浸镀时间为10 s时,镀层成型最好,高频感应电流为270 A,加热时间30 s时,抗拉强度达到167.12 MPa,比不浸镀的接头强度高63.8%.主要是因为镀层限制钢中的Fe原子和Al-Si钎料中的Al,Si原子的相互扩散,在热浸镀不锈钢与铝合金反应中使Fe₂Al₅转化为Fe（Al,Si）₂固溶体而未形成5-Al₈Fe₂Si化合物,降低了界面上硬脆化合物的含量,力学性能随之提高.     

Diffusion bonding of copper alloy to stainless steel with Ni and Cu interlayer

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣｕＡｌＢｅａｌｌｏｙｉｓａｎａｔｔｒａｃｔｉｖｅｓｈａｐｅｍｅｍｏｒｙａｌｌｏｙｆｏｒｕｓｅｉｎｍａｎｙｉｍｐｏｒｔａｎｔｉｎｄｕｓｔｒｉａｌｃｏｍｐｏｎｅｎｔｓｔｏｒｅｄｕｃｅｓｈｏｃｋａｂｓｏｒｐｔｉｏｎｄｕｅｔｏｉｔｓｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ ,ｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅ,ｄａｍｐｉｎｇ ｐｒｏｐｅｒｔｙａｓｗｅｌｌａｓｇｏｏｄｓｈｏｃｋａｂｓｏｒｐｔｉｏｎａｎｄａｎｔｉ ｎｏｉｓｅｐｒｏｐｅｒ ｔｉｅｓ[1～ 3].Ｈｏｗｅｖｅｒ,ｉｎｏｒｄｅ…     

Effect of process parameters on microstructure and properties of laser welded joints of aluminum/steel with Ni/Cu interlayer

The effects of laser parameters and interlayer material on the microstructure and properties of the welded joint between 6061 aluminum alloy and stainless steel were studied. The results show that the density and microstructure of the welded joint can be optimized by changing the laser power with 0.05 mm Cu foil and 0.1 mm Ni foil as interlayer. A large number of new Cu–Al binary phases were found near the aluminum alloy, which effectively inhibited the formation of the binary brittle phase of Fe–Al. The maximum shear force of 1350.96 N was obtained with laser power of 2200 W. The shear force of the welded joint increased to 1754.73 N when the thickness of the Cu foil thickness changed to 0.02 mm.     

Interfacial structure and bond strength of ultrasonic brazed Al–304 stainless steel dissimilar joints

Abstract

A filler alloy (Zn–14 at.-%Al) was used to join aluminium to 304 type stainless steel by ultrasonic brazing at 673 K for different ultrasound application times. Different reaction layers could be observed at the interface, containing Fe–Al, Fe–Zn, and Al–Zn solid solutions. As the amount of these solid solutions increased at the interface, there was a gradual improvement in the joint bond strength. The maximum bond strength of 146 MPa was obtained for the Al–304 joint brazed at 673 K for 3 s ultrasound application time. A critical remaining thickness of the filler alloy after ultrasonic application improves the interfacial joining. Extending the ultrasound application time beyond 3 s causes a bulk escape of the brazing alloy from the interface and leads to a direct interaction between aluminium and 304, which increases the possibility of forming intermetallics, and consequently decreases the joint bond strength.     

Microstructure Evolution During Stainless Steel-Copper Vacuum Brazing with a Ag/Cu/Pd Filler Alloy: Effect of Nickel Plating

Vacuum brazing of stainless steel and copper plates was done using a silver-based filler alloy. In one set of experiments, around 30-µm-thick nickel coatings were electrochemically applied on stainless steel plates before carrying out the brazing runs and its effect in making changes in the braze-zone microstructure was studied. For brazing temperature of 830 °C, scanning electron microscopy examination of the braze-zone revealed that relatively sound joints were obtained when brazing was done with nickel-coated stainless steel than with uncoated one. However, when brazing of nickel-coated stainless steel and copper plates was done at 860 °C, a wide crack appeared in the braze-zone adjacent to copper side. Energy-dispersive x-ray analysis and electron microprobe analysis confirmed that at higher temperature, the diffusion of Cu atoms from copper plate towards the braze-zone was faster than that of Ni atoms from nickel coating. Helium leak rate of the order 10^?11 Pa m³/s was obtained for the crack-free joint, whereas this value was higher than 10^?4 Pa m³/s for the joint having crack. The shear strength of the joint was found to decrease considerably due to the presence of crack.     

Interfacial features of TiAl alloy/316L stainless steel joint brazed with Zr−Cu−Ni−Al amorphous filler metal

TiAl alloy and 316L stainless steel were vacuum-brazed with Zr?50.0Cu?7.1Ni?7.1Al (at.%) amorphous filler metal. The influence of brazing time and temperature on the interfacial microstructure and shear strength of the resultant joints was investigated. The brazed seam consisted of three layers, including two diffusion layers and one residual filler metal layer. The typical microstructure of brazed TiAl alloy/316L stainless steel joint was TiAl alloy substrate/α₂-(Ti₃Al)/AlCuTi/residual filler metal/Cu₉Zr₁₁+Fe₂₃Zr₆/Laves-Fe₂Zr/α-(Fe,Cr)/316L stainless steel substrate. Discontinuous brittle Fe₂Zr layer formed near the interface between the residual filler metal layer and α-(Fe,Cr) layer. The maximum shear strength of brazed joints reached 129 MPa when brazed at 1020 °C for 10 min. The diffusion activation energies of α₂-(Ti₃Al) and α-(Fe,Cr) phases were ?195.769 and ?112.420 kJ/mol, respectively, the diffusion constants for these two phases were 3.639×10^?6 and 7.502×10^?10 μm²/s, respectively. Cracks initiated at Fe₂Zr layer and propagated into the residual filler metal layer during the shear test. The Laves-Fe₂Zr phase existing on the fracture surface suggested the brittle fracture mode of the brazed joints.