TC4/Ni/QAl10-3-1.5扩散连接研究

采用N i箔做中间层在真空下对TC4和QA l10-3-1.5进行扩散连接,用冷场发射扫描电镜(JEOL JSM 6700F)对焊接接头进行金相和能谱分析,用X射线衍射进行相分析,并进行硬度试验和接头拉伸试验。结果表明,在连接温度870℃,连接压力10MPa,保温时间60 m in规范下,N i做中间层能够实现TC4和QA l10-3-1.5扩散连接,其抗拉强度达到325 MPa。扩散连接界面形成了不同的分层结构,由形成了N iTi相,(N iTi+N i3Ti)相和N i(Cu)固溶体构成的扩散反应层。     

TC4/Cu/ZQSn10-2-3扩散连接接头微观分析

TC4/ZQSn10-2-3直接扩散连接时,结合区由于生成CuSn_3Ti_5,Cu_3Ti等金属间化合物及集聚的Pb质点,接头强度不高(τ_(max)=102 MPa),断口为脆性断口,并发生在靠近ZQSsn10-2-3侧;填加金属中间层铜时,TC4/Cu/ZQSn10-2-3扩散连接接头强度获得显著提高(τ_(max)=196 MPa),这主要是铜中间层有效地抑制了Sn,Pb等元素向TC4侧的扩散,减少CuSn_3Ti_5,Cu_3 Ti等金属间化合物相生成,断口具有一定塑性;TC4/Cu,ZQSn10-2-3最佳扩散连接参数为:连接温度830℃,连接压力10 MPa,连接时间30 min.

Abstract：

The experimental investigation on the diffusion bonding of TC4 to ZQSn10-2-3 was carried out in vacuum. CuSn_3 Ti_5, Cu_3 Ti and rich-Pb layer were formed at the interface zone. The maximum joint strength was 102 MPa. Brittle fracture was explored after shear test, and occurred proximity to ZQSn10-2-3 side. Using copper as the interlayer, element Sn and Pb can be avoid diffusing from ZQSn10-2-3 to TC4. Then there were little CuSn_3Ti_5 in the interface. Fracture had certain plasticity, and the maximum strength of joint was 196 MPa. The optimum bonding parameters were: bonding temperature T = 830 ℃ , bonding pressure p = 10 MPa and bonding time t = 30 min.     

用中间层为非活性金属FeNi/Cu的Si3N4陶瓷与Ni的扩散连接

采用非活性金属中间层FeNi/Cu在高、低真空条件下进行了Si3N4陶瓷与Ni的扩散连接,然后对部分接头进行了热等静压（HIP）后处理,测定了连接接头的四点弯曲强度,用扫描电镜（SEM）、电子探针（EPMA0和X射线衍射仪（XRD）对连接界界面区域进行了分析。结果表明,采用非活性金属中间扩散连接Si3N4陶瓷与Ni,在高真空和低真空条件下均能获得高强度连接,连接界面处没有形成Ni-Si化合物反应层,连接时间对接头强度的影响不明显。上述特征与用活性多种中间层连接时的情况截然不同。本文的连接方法有着重要的工程应用前景。     

Mg/Al异种材料真空扩散焊界面区域的显微组织

采用真空扩散焊技术对Mg／Al异种材料进行了焊接。采用金相显微镜、扫描电镜(SEM)、显微硬度计及X射线衍射(XRD)对扩散界面附近的显微组织及性能进行了试验研究。试验结果表明，Mg／Al异种材料真空扩散焊在加热温度Tp=450-490℃，压力强度P=0．08-0．10MPa，保温时间t=40-60min时能得到良好的扩散焊接头。扩散焊界面过渡区形成了致密的新相化合物层，断口形貌呈粗糙暗灰色，以解理断裂为主并伴有脆性的混合型断口，扩散界面过渡区生成了MgAl、Mg3Al2、Mg2Al3等金属间化合物。     

钛/铜中间层/钢扩散焊复合管界面组织与性能

以铜箔为中间层,采用拉拔—内压扩散法制备钛/钢复合管.利用光学显微镜、扫描电子显微镜、X-光衍射仪和能谱仪对界面组织、断口形貌和成分进行分析,通过剪切试验测定界面的结合强度.结果表明,以铜箔作中间层,拉拔—内压扩散法实现了钛/钢的冶金结合;在钛/铜界面处发生了明显的原子扩散,并形成不同的扩散层;随着扩散温度和时间的增加扩散层的厚度逐渐增加;中间层的加入阻止了固相扩散中钛铁、钛碳脆性化合物生成;钛/钢界面的抗剪强度随着扩散温度的升高先增加后降低,铜层的加入使抗剪强度明显提高,最高可达310 MPa.     

Al2O3-TiC复合陶瓷与Q235钢扩散连接界面组织结构

采用Ti/Cu/Ti复合中间层通过液相扩散连接技术实现了Al2O3-TiC复合陶瓷与Q235低碳钢的扩散连接.采用扫描电镜、电子探针及X射线衍射等测试手段对Al2O3-TiC/Q235扩散连接接头的显微组织、断口形貌及相组成进行了分析.结果表明,Al2O3-TiC/Q235界面结合紧密,没有显微孔洞、裂纹及未连接区域;Al2O3-TiC/Q235界面附近有各种各样的新相生成,如TiO,Ti3Al,Cu2Ti4O及Cu3Ti3O,所生成的TiO相及复杂结构氧化物Cu3Ti3O和Cu2Ti4O都具有金属特性,对于促进Al2O3-TiC/Q235的可靠连接起到重要作用;接头抗剪强度达143MPa,断口表现为脆性断裂特征,Al2O3-TiC/Q235接头断在界面附近的Al2O3-TiC内.     

Formation mechanism of periodic layered structure in Ni3Si/Zn system

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, γ phase 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.     

添MgO-Y_2O_3的Fe-Mo包覆Si_3N_4复合粉末反应烧结中组织形成与演化分析

在非均相沉淀法制备的Fe-Mo包覆Si3N4金属陶瓷粉末中添加助剂MgO-Y2O3进行常压烧结,采用X线衍射仪(XRD)、电子能谱(EDS)、电镜扫描(SEM)等方法研究了不同烧结温度下该金属陶瓷相组成和显微结构等方面的演化趋势。结果表明:温度升高有利于金属相的转变和液相的生成,在复合粉末还原过程中,Si3N4的强还原性将Mo、Fe依次直接还原出来并反应生成Fe3Mo化合物,随着还原温度的升高,该金属间化合物与Si3N4反应生成Fe3Mo3N;同时Mg、Y氧化物与基体反应生成的MgSiO3、Fe17Y2加速了Fe3Mo3N的形成。1 600℃烧结时,Fe3Mo3N仍能稳定存在,但在1 700℃烧结时发生分解,材料组织中出现大量长径比较高的晶须状物质生成,同时表面粘附一层小颗粒物质.烧结温度为1 750℃时,金属小颗粒相仍得以保留,材料基体中晶须状物质消失。     

扩散焊接钨/钒/钢体系的界面结构及力学性能

采用厚度为0.5 mm钒片作为中间层,在1050℃/10 MPa/1 h的工艺条件下,对钨/钢异种材料进行扩散焊接.采用扫描电镜、能谱仪和纳米压痕分别对接头的微观组织、元素分布及显微硬度进行分析和测试;对接头的拉伸性能进行测试,并对其断口形貌和元素分布进行分析.结果表明,利用母材与中间层之间元素的相互扩散,可实现钨/钢材料的焊接;钨/钢焊接接头界面区由钨-钒固溶体层、未反应钒层及钒-钢扩散层3部分组成,其中钒-钢界面层结构为钒/VC层/脱碳层/钢;钢/钒扩散层具有最高的显微硬度;钨/钢接头抗拉强度为75 MPa,含脆性相VC的钒/钢界面是接头失效的主要断裂源.     

Nb、Cu金属层厚度对Si3N4/Nb/Cu/Ni/Incone l600接头组织和性能的影响

采用Nb／Cu／Ni作中间层，在连接温度为1403K、连接时间为50min、连接压力为7．5MPa的条件下，采用不同尺寸的中间层进行了Si3N4陶瓷与Inconel 600高温合金的部分液相扩散连接。通过改变Nb层、Cu层厚度，研究了Cu层、Nb层厚度变化对Si3N4／Nb／Cu／Ni／Inconel 600接头的组织和性能的影响。研究发现，当Cu层厚度小于0．05mm时，随着Cu层厚度的增加，接头中的Cu—Ni合金层厚度增加，接头强度快速增加；当Cu层厚度超过0．05mm时，接头中的Cu—Ni合金层厚度由于压力的作用不明显增加，接头强度增加缓慢。随着Nb层厚度的增加，反应层厚度增加，接头的强度先增大后减小。     

Effect of bonding parameters on microstructure and properties of Si_3N_4/Si_3N_4 joint brazed by Cu-Zn-Ti filler alloy

1INTRODUCTION Si3N4ceramichashighthermalandwearingresistanceandisapromisingmaterialforhightem peratureapplications.However,itisdifficultto manufacturetheSi3N4ceramicworkpieceswithla gerdimensionsandcomplicatedshapesduetoitspoorworkabilityandlowductility.Inrecent20years,manystudieshavebeenfocusedonthetech niquesofceramicjoining,becausethejoiningtech niquescanbeusednotonlyforlow costandhigh reliabilitymanufacturingofceramicpartswith complicatedshapesbutalsoforrepairingofthece ramicpartsinw…     

Study on interfacial structure and strength of Si3 N4/Ti/Cu/Ti/Si3 N4 PTLP bonding

Partial transient liquid-phase bonding (PTLP bonding) of Si3N4 ceramic with Ti/Cu/Ti multi-interlayer is performed with changing the thickness of Ti foil. The influence of Ti foil thickness on interface structure and joint strength was discussed. The joint interface structures are investigated by scanning electron microscope (SEM) and energy dispersion spectroscopy(EDS). The results show that the maximum joint strength of 210 MPa is obtained at room temperature in the experiments. When joining temperature and time are not changed and the process of isothermal solidification is sufficient,interface structure, reaction layer thickness and isothermal solidification thickness change with the thickness of Ti foil.     

铁中间层钛-钢扩散复合界面组织与性能

利用真空扩散焊方法制备了铁中间层钛-钢扩散焊接头,并采用OM、SEM、EDS、XRD、显微硬度和拉伸试验方法,研究了铁中间层钛-钢扩散复合界面组织和性能。结果表明,在900～1050℃、30 min扩散条件下,Fe、Ti原子在界面处发生了互扩散;钛侧形成βTi+α-βTi+αTi组织,钢侧发生脱碳,铁中间层形成柱状晶组织;拉伸强度随扩散温度升高呈现先增加后减小的趋势,900℃、30 min扩散试样拉伸强度最高,达到260 MPa;拉伸断口具有粗糙断裂区、脆性断裂区及二次断裂区特征,并在断口上检测出TiC、FeTi和Fe2Ti相。     

铜中间层钛-钢扩散复合界面组织与性能

利用真空扩散焊方法制备了铜中间层钛-钢焊接接头,并采用OM、SEM、EDS、显微硬度和拉伸试验方法,研究了铜中间层钛-钢扩散复合界面组织和性能。结果表明,Fe、Ti原子在界面处发生了互扩散,钛侧形成α-βTi+αTi或βTi+α-βTi+αTi组织,钢侧发生脱碳并形成柱状晶组织;拉伸强度随扩散温度升高呈现先增加后减小的趋势,950℃、30 min扩散试样拉伸强度最高,达到262 MPa;拉伸断口具有塑性断裂区与脆性断裂区特征,并在断口上检测出TiC相。     

Cu-Ni-Ti钎料连接Si3N4/In718接头强度及断裂分析

采用(Cu85Ni15)80Ti20钎料进行了Si3N4/In718合金的连接。结果表明，两者直接钎焊时连接强度较低，仅为11MPa；插入中间层Ni可有效减缓接头中V的残余应力，提高连接强度。Ni中间层存在一最佳厚度0．45mm，对应的连接强度达103MPa。断裂分析表明；不同的断裂方式其连接强度不同。断口XRD分析表明：界面反应产物包括TiN，Ti5Si4，Ti3Si和Ni3Si等化合物。     

Microstructure of reactive sintered Al bonded Si3N4-SiC ceramics

Aluminium nitride-silicon nitride-silicon carbide （AIN-Si3N4-SiC） composite ceramics were prepared to increase the bending strength and improve the phase structure of Si3N4-based ceramics. The ceramics were made by reactive sintering in N2 atmosphere at 1 360 ℃, using Al as sintering additive. The phase composing of ceramics was identified with an X-ray diffractometer and the microstructure of the materials was studied by scanning electron microscopy. The results indicate that the phase structure is affected remarkably and the interface modality is changed. The interface between Si3N4 and SiC becomes blurry and that between SiC and AlN matches more better at the same time. But the liquid-phase appears during the reactive sintering along with the addition of AI by which the melting point of Si is decreased. The appearance of liquid Si decreases the bending strength of the ceramics. Lower temperature nitrification technic was introduced to avoid the appearance of liquid-phase Si. The optimum addition of Al was investigated by XRD and SEM analysis in order to obtain the maximal bending strength of materials.     

Si3N4/AgCu/TiAl钎焊接头界面结构及性能

采用AgCu非活性钎料实现了Si3N4陶瓷与TiAl基合金的钎焊,确定接头的典型界面组织结构为:TiAl/Ti3Al+Ti(s,s)/AlCuTi/Ag(s,s)+AlCu2Ti/Ti5Si3+TiN/Si3N4陶瓷。钎焊过程中,活性元素Ti从TiAl母材溶解到钎料中与Si3N4陶瓷发生反应润湿,实现了TiAl与Si3N4陶瓷的连接。随着钎焊温度的升高及保温时间的延长,靠近Si3N4陶瓷的TiN反应层厚度增加,Ag基固溶体中弥散分布的AlCu2Ti化合物聚集长大成块状,导致接头性能下降。当钎焊温度T=860℃,保温时间为5min时接头抗剪强度达到最大值124.6MPa。基于反应热力学及动力学计算TiN层反应激活能Q约为528.7kJ/mol,860℃时该层的成长系数KP=2.7×10-7m/s1/2。     

93W/Ni/QSn4-3扩散焊接接头的显微结构和力学性能

采用扩散焊接的方法制备出加入Ni箔中间层的钨合金(93w)与锡青铜合金(QSn4-3)焊接接头样品.利用XRD,SEM和EPMA对焊接接头的物相组成和显微结构进行了分析,并测量了焊接接头样品的抗拉强度.结果表明,加镍的93W与QSn4-3进行扩散焊接时,焊接层的显微结构结合紧密,Ni与Cu元素之间以及93W合金的添加剂元素在Ni箔中分布存在明显的连续变化层.物相分析和显微硬度结果表明Ni元素与QSn4-3中的Cu元素和93W的添加剂元素的固溶反应,促进了93W,Ni/QSn4-3焊接接头强度的大幅度提高.

Abstract：

The 93W/Ni/QSn4-3 joint was prepared by diffusion bonding at vacuum using pure nickel foil as interface layer. The microstructure and composition were characterized by SEM and EP-MA. The tensile strength of joint was also measured. The test results show that Ni foil improves the tensile strength of 93W/Ni/QSn4-3 joint. The thickness of Ni interlayer becomes thiner obviously because of the diffusion layer between Ni element of Ni foil and W and additional elements of 93W alloy, as well as the gradient layer of Ni and Cu elements. Solution reactions between Ni element of Ni foil and Cu element of QSn4-3 alloy, W and additional elements of 93W alloy achieve the joint of 93W/Ni/QSn4-3, that is why tensile strength of 93W/Ni/QSn4-3 joint welded is improved.     

钛合金与GCr15扩散连接界面组织特征与性能

钛合金/轴承钢异种结构连接困难是制约钛合金广泛应用的瓶颈.采用电子拉伸显微硬度测试、SEM扫描、能谱、X射线衍射等分析手段,分析研究了Ti-6Al-4V/Cu/GCr15真空扩散焊接头的力学性能、组织结构特征、连接界面的原子扩散机制、反应相生成及其分布范围.结果表明,在焊接压力4.9MPa,焊接时间1.8ks条件下,接头的抗拉强度随焊接温度升高而增大,1273K达到最大为206MPa.延长焊接时间会导致金属间化合物厚度增大,对接头性能不利.接合界面间生成的α-Ti(Cu)固溶体,有固溶强化效果,对提高接头性能有利.而生成的金属间化合物Ti2Cu,Ti2Cu3,(Ti3Cu4)FeTi中的TixCuy对接头性能影响较大,导致接头强度下降.铜作为钛合金与GCr15的中间过渡层不宜过厚.