Ag-Cu-Ti合金制备技术及钎焊应用综述

介绍了Ag-Cu-Ti活性钎料的主要制备方法,常用的Ag-Cu-Ti活性钎料及熔化温度,Ag-Cu-Ti钎料钎焊各种陶瓷与陶瓷或陶瓷与金属,Ag-Cu-Ti活性钎料钎焊金刚石、石墨、玻璃、立方氮化硼、复合材料的应用研究进展及Ag-Cu-Ti活性钎料的改性研究。     

Ag-Cu-Ti活性钎料真空钎焊钼和石墨结合质量研究

为了实现石墨与钼的高强连接,实验采用活性钎料Ag-Cu-Ti作为填充材料,研究了钎焊过程中采用的工艺及不同种类石墨对真空钎焊接头组织结构和性能的影响,进一步探讨了界面结合机理.利用光学显微镜分析了接头微观形貌,采用能谱仪确定了接头的成分分布,采用自行设计的模具测试了接头的剪切强度.结果表明,Ag-Cu-Ti钎科与两侧钼和石墨基体均形成了良好的结合界面,接头抗剪强度达到了石墨基材强度的80%以上;石墨密度对接头性能的影响比较大,导致钎缝区出现不同的界面形貌.可以通过表面物理改性的方法改善接头质量.     

TLP bonding of alumina ceramic and 5A05 aluminum alloyusing Ag-Cu-Ti interlayer

In order to join alumina ceramic to 5A05 aluminum alloy and obtain the excellent airtightness of joints whose maximum service temperature is 623 K,transient liquid phase (TLP) bonding technique was investigated using Ag-Cu-Ti alloy as interlayer.The wetting experimental results confirm that Ti can react with alumina ceramic at 833 K by adding 2 wt.% Ti in Sn.But during bonding alumina ceramic and 5A05 aluminum alloy with Ag-Cu-Ti interlayer at 833 K,Ti preferentially reacts with Al and there is no reaction layer on alumina ceramic/Ag-Cu-Ti interface,which finally results in a poorly airtight joint.     

AlN/Mo-Ni-Cu的活性封接研究

采用Ag_(70)-Cu_(28)-Ti_2活性焊料在真空条件下对AlN陶瓷和Mo-Ni-Cu合金进行活性封焊.分析焊区的显微组织形态、相组成,测定焊区力学性能和气密性.结果表明:在焊料层与合金的界面处Cu的含量相对较高,而在AlN陶瓷与焊料层的界面处形成了厚度为1～2 μm的富Ti层;经XRD分析发现,AlN陶瓷与焊料层的界面上有TiN存在,表明在AlN陶瓷与焊料层的界面处形成了化学键合.焊接后试样的气密性达到1.0×10~(-11) Pa·m~3/s,抗弯强度σ_b=78.55 MPa,剪切强度σ_τ=189.58 MPa.     

活性钎焊法连接碳化硅陶瓷的连接强度和微观结构

采用三元Ag-Cu-Ti活性焊料连接常压烧结碳化硅陶瓷,研究了反应温度、保温时间等钎焊工艺对碳化硅陶瓷连接强度的影响,分析了连接界面的微观结构和反应产物. 实验结果表明,在实验范围内,钎焊温度和保温时间对碳化硅陶瓷的连接强度均有峰值,四点弯曲强度最高达到342MPa,随着钎焊温度的升高,界面反应层厚度增加,连接强度提高,但过高的钎焊温度引起焊料的挥发而使连接强度下降. 焊料中的活性元素Ti与碳化硅发生反应在连接界面形成均匀致密的反应层,反应层厚度约1μm,XRD和EDX能谱分析结果表明反应产物是TiC和Ti₅Si₃.     

Joining interface and compressive strength of brazed cubic boron nitride grains with Ag-Cu-Ti/TiX composite fillers

Ag-Cu-Ti/TiX (TiX=TiB₂, TiN or TiC) composite filler materials, instead of pure Ag-Cu-Ti alloy, were developed to improve the comprehensive mechanical performance of brazed joints of cubic boron nitride (CBN) grains/bonding layer/steel matrix. This article mainly concerns the effects of TiX addition on the joining interface and compressive strength of brazed CBN grains. The results demonstrate that, due to the variation of chemical activity of Ti atoms induced by TiX addition into the brazing system, the brazing reactions, especially chemical resultants produced at the joining interface between CBN grain and Ag-Cu-Ti alloy, are restrained to some extents. In general, the TiN particles show the greatest suppression effect on the brazing resultants, while the TiC particles have the weakest effect, and TiB₂ particles have the medium effect. The optimum reinforcement of the composite filler is finally determined as the TiB₂ particles with the content of 8 wt%, with which the average compressive strength of brazed CBN grains reaches 15 N, which is nearly the same high as that of original CBN grains.     

A Research on the Joining of SiC Composite to 40 Cr Steel

SiC composites and 40 Cr Steels were joined with Ag-Cu-Ti solder in order to develop a new method of joining ceramics to metal. Effects of solder component and process parameters on the joining strength were investigated. The results show that some chemical reactions occur on the jointing interface between ceramics and metal. Higher joining strength is achieved when titanium is 0.2% (mass fraction) in the solder. The thickness of solder also affects the joining characteristics, and 0.2-0.3 mm thickness of solder is the most suit-able.     

采用Ag-Cu-Ti+Mo复合钎料钎焊Si3N4陶瓷

采用Ag-Cu-Ti+Mo复合钎料连接Si3N4陶瓷,利用SEM,TEM,Nanoindentation研究了钎料内钼颗粒含量对接头组织和力学性能的影响.结果表明,在Si3N4/钎料界面处形成了一层致密的反应层,该反应层由TiN和Ti5Si3组成.接头的中间部分由银基固溶体、铜基固溶体、钼颗粒和Ti-Cu金属间化合物组成.借助于纳米压痕技术测定了接头内Ti-Cu化合物以及钎料金属的弹性模量和硬度值.随着钎料内钼颗粒含量的提高,母材/钎料界面反应层厚度逐渐降低;钎料金属中Ti-Cu化合物数量增多;此外,银和铜基固溶体组织逐渐变得细小.当添加5%Mo时,得到最高的接头强度429.4 MPa,该强度相比合金钎料提高了114.7%.     

Si_3N_4－钢铁钎接用银－铜－钛钎料及其钎接工艺

研究了合金型Ａｇ－Ｃｕ－Ｔｉ钎料成分对Ｓｉ_３Ｎ_４浸润性及钎接温度对该系钎料钎接Ｓｉ_３Ｎ_４－钢铁的钎接强度的影响。用该工艺进行Ｓｉ_３Ｎ_４电热塞中Ｓｉ_３Ｎ_４发热体与金属外套的钎接，经综合测试可知满足Ｓｉ_３Ｎ_４电热塞技术要求。     

Ag-Cu-Ti活性钎料热力学分析

在陶瓷与金属的活性钎焊连接技术中，Ag—Cu—Ti合金是研究和应用最多的钎料之一。合金组元Ti的活度是影响钎料／陶瓷界面反应的关键因素，对钎料与陶瓷的润湿性和连接能力起着重要的作用。作者借助热力学对Ag—Cu—Ti活性钎料进行了热力学分析，重点分析了Ti的热力学活度及其与组分浓度之间的关系，计算了各组分之间的相互作用参数。分析和计算结果表明，Ti的活度随着Cu含量的增加而减小，随着Ag含量的增加而增大；Ag与Ti之间存在较大的排斥作用，两者的相互作用参数为32．83kJ／mol；而Cu与Ti之间存在强烈的吸引作用，其相互作用参数为-16．14kJ／mol；Ag—Cu—Ti合金中添加某些与Cu的结合力大、与Ti的结合力小、且与合金组元不形成高熔点化合物或脆性相的合金元素，有利于提高合金中的Ti活度。