陶瓷/金属钎焊与扩散连接的研究现状

工程陶瓷由于具有优异的综合性能,在许多领域得到广泛应用,但其加工性能差,通常需要与金属组成复合结构.实现陶瓷与金属之间的可靠连接是推进陶瓷材料应用的关键,钎焊和扩散连接被认为是陶瓷/金属连接中较为适合的方法.文中对近年来国内外陶瓷/金属钎焊和扩散连接技术领域的研究现状进行了综述,认为活性金属钎焊和部分瞬间液相连接发展比较成熟,部分瞬间液相连接充分结合了活性钎焊和固相扩散连接两者的优点,将成为未来陶瓷/金属连接的发展方向.     

Comparison in interfacial phenomena in electric-field assisted anodic bonding of Kovar-glass and Kovar/Al film-glass

0　ＩｎｔｒｏｄｕｃｔｉｏｎＡｎｏｄｉｃｂｏｎｄｉｎｇｉｓａｐｒｏｍｉｓｉｎｇｔｅｃｈｎｉｑｕｅｆｏｒｇｌａｓｓ ｔｏ ｍｅｔａｌｓｅａｌｉｎｇａｔｔｅｍｐｅｒａｔｕｒｅｓｓｉｇｎｉｆｉｃａｎｔｌｙｌｏｗｅｒｔｈａｎｔｈｏｓｅｕｓｅｄｉｎｔｈｅｃｏｎｖｅｎｔｉｏｎａｌｔｈｅｒｍａｌｓｅａｌｉｎｇ[1 ,2 ] .Ａｎｏｄｉｃｂｏｎｄｉｎｇｈａｓａｖａｒｉｅｔｙｏｆａｐｐｌｉｃａｔｉｏｎｓｉｎｃｌｕｄｉｎｇｍｉｃｒｏｓｅｎｓｏｒｓ,ｐｈｏｔｏｖｏｌｔａｉｃｓａｓｗｅｌｌａｓｍｉｃｒｏｅｌｅｃｔｒｏｎｉｃｄｅｖ…     

Effect of joining temperature on the microstructure and strength of tungsten/ferritic steel joints diffusion bonded with a nickel interlayer

A diffusion bonding process, for joining of tungsten to ferritic steel using nickel as an interlayer, was developed for nuclear component application. The effect of joining temperature on the microstructure and tensile strength of the joint was investigated in this work. Metallographic analysis revealed that a good bonding was obtained at both the tungsten/nickel and nickel/steel interfaces, and the diffusion products were identified in the diffusion zone. Nano-indentation test across the joining interfaces demonstrated the effect of solid solution hardening in the diffusion zone. Tensile test showed that the maximum average tensile strength of ∼200 MPa was obtained for the joint diffusion bonded at 900 °C. The results were discussed in terms of the joining temperature and of the residual stress generated during joining process.     

Numerical modelling and experimental investigation of diffusion brazing SS304/BNi-2/SS304 joint

Abstract

The kinetics of dissolution and isothermal solidification at the bonding temperature during diffusion brazing SS304/BNi-2/SS304 has been studied through a combination of analytical modelling and experimental investigations. The modelling is based on the diffusion theory and the consideration of transient motion of liquid/solid interface. A set of coupled finite differential equations has been programmed to track the motion of liquid/solid interface during the isothermal solidification of liquid filler. Four parameters can be mathematically determined from the analytical modelling including the evolution of solute concentration profile, the maximum diffusion distance, and the maximum liquid thickness as well as the time to complete the isothermal solidification. These analyses are helpful to understanding the joining mechanism during diffusion brazing. The temperature dependent diffusion coefficient used in the modelling is derived together with the experimental data from brazing the wedge shaped joint specimen of SS304/BNi-2/SS304. The effects of bonding temperature and initial joint thickness on the joining process have also been investigated.     

Nature of CoCrFeMnNi/Fe and CoCrFeMnNi/Al Solid/Solid Interface

To shed light into the application potential of high-entropy alloys as "interlayer" materials for Al-steel solid-state joining,we investigated the nature of the CoCrFeMnNi/Fe and CoCrFeMnNi/Al solid/solid interfaces,focusing on the bonding behav-ior and phase components.Good metallurgical bonding without the formation of hard and brittle IMC can be achieved for CoCrFeMnNi/Fe solid/solid interface.In contrast to the formation of Al5Fe2 phase at the Fe/Al interface,Al13Fe4-type IMC,in which the Fe site is co-occupied equally by Co,Cr,Fe,Mn and Ni,dominates the CoCrFeMnNi/Al interface.Although the formation of IMC at the CoCrFeMnNi/Al interface is not avoidable,the thickness and hardness of the Al13(CoCrFeMnNi)4 phase formed at the CoCrFeMnNi/Al interface are significantly lower than the Al5Fe2 phase formed at the Fe/Al interface.The activation energies for the interdiffusion of Fe/Al and CoCrFeMnNi/Al static diffusion couple are 341.6 kJ/mol and 329.5 kJ/mol,respectively.Despite this similarity,under identical static annealing condition,the interdiffusion coefficient of the CoCrFeMnNi/Al diffusion couple is significantly lower than that of the Fe/Al diffusion couple.This is thus mainly a result of the reduced atomic mobility/diffusivity caused by the compositional complexity in CoCrFeMnNi high-entropy alloy.     

钢—铝固液相复合中浸镀助焊剂的应用研究

采用浸镀助焊剂的方法研究了助焊剂对钢－铝固液棹复合质量的影响。结果表明，浸镀助焊剂方法可以解决钢－铝固液相复合中接触界面氧化问题，以卤化物为主的助焊剂１号可大幅度提高钢－铝固液相复合界面的结合强度。     

GH99合金液相扩散连接界面组织分析

采用自制Ni-Cr-Si-B系列中间层对GH99镍基高温合金进行了液相扩散连接（TLP）,借助扫描电子显微镜（SEM）、能谱分析仪（EDS）等分析手段研究了焊接工艺参数以及中间层成分变化对接头界面组织的影响.结果表明,随着等温时间和焊接温度的增加,析出化合物的数量减少,接头组织更加均匀.接头中化合物的析出主要与降熔组元的扩散有关,中间层中B元素作为降熔组元,其含量的多少直接影响着接头化合物的形成数量;而Si元素由于在母材中的固溶度较高,其化合物在焊接过程中不易析出.     

Computational simulation of diffusion process in multicomponent and multiphase systems in diffusion bonding

Abstract

Diffusion bonding is a solid state welding process useful for joining similar and dissimilar metals. In the present paper, the interdiffusion occurring during the diffusion bonding of Al to Zn, Al to Mg, and one Ni base alloy to another was investigated. The composition profiles across the interface, the thickness of the diffusion layer and the growth of phases at the interface were computed using the diffusion software Pandiffusion and the thermodynamic and kinetic databases of Pandat. The calculated results agreed well with existing experimental data. Thus, it was demonstrated that these software and databases can be useful for studying diffusion bonding and reducing the number of trial-and-error experiments.     

Influence of diffusion time on steel-mushy Al-7 graphite bonding

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｃｏｍｍｏｎｓｔｅｅｌ ｂａｃｋｅｄＡｌｂａｓｅｂｏｎｄｉｎｇｐｌａｔｅｉｎｃｌｕｄｅｓｓｔｅｅｌ ｂａｃｋｅｄＡｌ Ｓｎｂｏｎｄｉｎｇｐｌａｔｅ[1 ,2 ] ａｎｄｓｔｅｅｌ ｂａｃｋｅｄＡｌ Ｐｂｂｏｎｄｉｎｇｐｌａｔｅ[3 ,4] ｍ     

Effect of clad ratio on interfacial microstructure and properties of cladding billets via direct-chill casting process

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.     

采用辅助脉冲电流液相扩散连接Ti(C,N)-Al_2O_3的接头形成行为及强度

采用辅助脉冲电流液相扩散连接方法,对Ti(C,N)-Al2O3陶瓷基复合材料与40Cr钢进行了焊接试验,重点研究了在辅助脉冲电流作用下,界面及焊缝组织演变、基体材料溶解等界面行为,探讨了工艺参数对接头强度及断口形态影响规律.结果表明,通过采用辅助脉冲电流液相扩散连接Ti(C,N)-Al2O3与40Cr钢,可以在较短的焊接时间条件下获得较为稳定的接头强度,四点弯曲平均强度位于231~272 MPa之间;降低焊接件整体加热温度以缓解接头残余应力,控制界面和焊缝化学冶金反应进程以较少金属间化合物数量、提高固溶体含量,抑制活性元素Zr向陶瓷基复合材料中的扩散进程以减少陶瓷颗粒向焊缝中的溶解量,是提升焊接接头强度的关键因素.     

不锈钢包覆半固态铝合金挤压连接成形的研究

采用包套挤压成形方法,成功地实现了不锈钢与半固态铝合金的连接与成形。采用数值模拟与试验相结合的方法,研究了不锈钢包套的变形行为以及铝合金固相率、挤压比对材料复合后界面强度和组织性能的影响,采用光学显微镜对界面组织结构进行了观察分析。结果表明,在大挤压比的情况下不锈钢包套破裂发生在凹模出口处,界面剪切强度随挤压比的增大而提高,固相率为30%时达到最大值;铝合金固相组织与低熔点液相组织以一定比例交替与不锈钢表面接触,由于液相扩散能力大于固相成分,从而形成非均匀扩散的新型界面组织。     

玻璃与金属连接技术研究进展

玻璃与金属连接技术已广泛应用于传感器的制造、包装及密封,因此研究玻璃与金属的连接有重要的科学意义和极大的工程价值。综述了玻璃-金属连接的基本问题:玻璃-金属连接的热应力与残余应力、玻璃表面的润湿及界面反应问题;较全面地介绍了几种连接工艺—匹配封接、阳极键合、钎焊、激光辅助连接、超声波摩擦焊、半固态连接及胶接;并提出了采用低温连接工艺来解决由于界面残余应力所引起的接头强度不高而失效是未来研究的重点。     

焊接温度对Mg/Al扩散焊接头微观组织和性能的影响

采用真空扩散焊在不同焊接温度下对AZ31B镁合金和6061铝合金进行连接。利用光学显微镜（OM）、扫描电镜（SEM）和能谱（EDX）观察Mg/Al异种金属接头的显微组织。结果表明：随着焊接温度的升高,扩散区各层的厚度增加,且组织发生明显变化。440°C时扩散层由Mg2Al3层和Mg17Al12层组成;460和480°C时由Mg2Al3层、Mg17Al12层和Mg17Al12与镁基固溶体的共晶层组成。随着加热温度的升高,高硬度区域显著增多,区域内不同位置的硬度存在明显差别。当焊接温度为440°C时接头的最大抗拉强度为37MPa,脆性断裂发生在Mg17Al12层。     

SiCp增强Al基复合材料的真空扩散焊接

采用真空扩散焊接方法研究了同质及异质ＳｉＣｐ增强Ａｌ基复合材料的连接特性,考察了ＳｉＣｐ体积分数变化及插入中间合金层对同质及异质Ａｌ合金基复合材料真空扩散焊接质量及接头性能的影响。研究结果表明,无论同质还是异质Ａｌ合金基复合材料,真空扩散焊接头的强度均随ＳｉＣｐ体积分数的增加而降低;获得满意的异质ＳｉＣｐ增强Ａｌ合金基复合材料的真空扩散焊连接远比同质材料时困难。研究结果还表明,无论同质还是异质Ａｌ     

热处理对Cu/Al-3.25Si合金冷压焊接复合带界面组织与性能的影响

利用金相显微镜、扫描电镜、万能材料实验机等,研究了Cu/Al-3.25Si合金冷压焊接复合带热处理工艺,讨论了界面层厚度、界面结合强度、铜铝金属间化合物生成规律等问题. 结果表明,随着热处理温度的升高和保温时间的增加,扩散层厚度的增长呈现先快再慢的趋势,动力学曲线时间指数在0.5~1之间;界面的结合强度随着热处理温度和保温时间的增加呈先升高后降低的趋势;界面金属间化合物有Cu₉Al₄,CuAl,CuAl₂等;最佳热处理温度宜控制在200~300 ℃,保温时间在2 h以内.     

扩散连接接头区域元素浓度分布的数值分析

扩散连接接头区域元素浓度的分布是扩散连接技术中影响被连接材料的扩散，相变，界面反应及接头质量的重要因素，为此人们借助于计算技术。对其进行数值模拟，以便对扩散连接过程及质量进行预测与实时控制，针对异种材料的扩散连接过程，以热力学第二定律为基础，进行了扩散连接接头区域元素浓度分布的数值分析，建立了生成固溶体类型的界面反应模型，以使人们能够定性或半定量的分析扩散连接因素对接头性能的影响。利用耐热合金K5与耐热钢2Cr12NiMoV的扩散连接对建立的模型的试验验证表明，模型能够较好的反映元素的分布规律，可以为扩散连接工艺参数的制定提供一定的参考。     

Al-Fe金属间化合物对复合板界面结合的影响(英文)

对固态铝和固态铁界面金属间化合物的生长及金属间化合物对界面结合的影响进行了研究。结果表明,固态铝和固态铁热处理后的界面主要包括Fe2Al5和FeAl3化合物层,金属间化合物恶化了界面结合强度。在拉剪测试中,断裂主要发生在Fe2Al5或FeAl3化合物层,断裂的位置主要取决于化合物层内部的缺陷,包括微裂纹和空洞。热膨胀系数不匹配产生的应力导致内部微裂纹产生,内部孔洞产生的原因是Kirkendall效应。该研究对铝和铁的焊接与连接,尤其是对铝钢复合板的制备,奠定了一定的基础。     

热塑性聚合物热熔接过程界面扩散行为分子动力学模拟

采用分子动力学模拟方法对热塑性聚合物的热熔接过程界面扩散行为进行了研究,建立了具有两个层晶胞的聚甲基丙烯酸甲酯(PMMA)界面模型,采用等温等压(NPT)系综分别对不同温度及压力下界面间分子链扩散行为进行了模拟,计算了PMMA界面体系原子扩散系数、扩散层厚度及界面结合能,分析了温度、压力等因素对界面扩散行为的影响规律....     

TA2/316L的连接技术及其腐蚀与防护

钛钢复合板既可以充分发挥基材各自的优点,也是节约贵金属最好的途径,在舰船上应用有明显的社会效益和经济效益,值得进一步应用推广。爆炸焊接、轧制复合、摩擦焊和扩散焊是目前主要的层状金属复合板的生产方法,其中,爆炸复合法在生产中应用最为广泛。本文通过分析TA2与316L的焊接性,对其连接方法和主要应用领域进行综述,概述了TA2/316L在海水介质中的主要腐蚀类型及防护方法。