稀土La改性Ag-Cu-Ti钎料的显微组织和力学性能

系统研究了钎焊CBN工具用稀土元素La改性Ag-Cu-Ti钎料合金的熔化温度、微观组织、显微硬度及钎料与45钢基体钎焊接头抗剪强度.结果表明,稀土元素La对Ag-Cu-Ti钎料合金的熔点影响很小,但是可以促进钎料的合金化,提高其合金化程度,稀土La加入量不超过0.5%(质量分数)时可以改善Ag-Cu-Ti钎料合金的微观组织,使金属间化合物分布更加均匀,提高Ag-Cu-Ti钎料合金的显微硬度,还可以明显改善钎料与45钢基体的钎焊接头抗剪强度.     

Ag70-Cu28-Ti2活性封接AlN陶瓷

研究了在真空条件下AlN陶瓷真空活性封接的情况,使用的活性焊料是Ag70-Cu28-Ti2熔炼焊片.通过试验可以得到该活性焊料在AlN片上润湿性良好,获得的AlN/AlN接头达到了气密性要求(漏气速率小于1×10-10 Pa·m3/s),平均强度值分别为1.49 kN/cm2(抗弯)和2.00 kN/cm2(抗剪切).通过扫描电镜及电子探针仪观察了焊层形貌和元素分布,分析了连接强度较高的原因.通过XRD确定了焊接的冶金结合及新相的生成.     

采用Ag-Cu-Ti钎料真空钎焊SiO2f/SiO2复合陶瓷与C/C复合材料

分别在880℃/10min和880℃/60min规范下,采用Ag-Cu-Ti活性钎料实现了SiO2f/SiO2复合陶瓷与C/C复合材料的真空钎焊连接,通过电子探针(EPMA)、能谱仪(XEDS)和X射线衍射仪(XRD)分析了接头微观组织,室温下测试了接头的抗剪强度。结果表明:两种规范下所得接头界面结合良好,接头中靠近两侧母材均形成了一层扩散反应层,钎缝基体主要由均匀的共晶组织组成。880℃/10min规范下钎焊接头界面产物依次为:SiO2f/SiO2→Ti4O7→Ti5Si4+Cu(s,s)+Ag-Cu共晶合金→TiC→C/C;对于880℃/60min规范下的接头,界面组织结构与保温10min的接头基本类似,但是不存在Cu(s,s),并且接头反应层明显增厚。880℃/60min条件下所得钎焊接头剪切强度平均值为16.6MPa。     

Interfacial microstructure and mechanical properties of zirconia ceramic and niobium joints vacuum brazed with two Ag-based active filler metals

Reliable brazing of a zirconia ceramic and pure niobium was achieved by using two Ag-based active filler metals, Ag-Cu-Ti and Ag-Cu-Ti+Mo. The effects of brazing temperature, holding time, and Mo content on the interfacial microstructure and mechanical properties of ZrO₂/Nb joints were investigated. Double reaction layers of TiO and Ti₃Cu₃O formed adjacent to the ZrO₂ ceramic, whereas TiCu₄+Ti₂Cu₃+TiCu compounds appeared in the brazing interlayer. With increasing brazing temperature and time, the thickness of the Ti₃Cu₃O layer increased with consumption of the TiO layer, and the total thickness of the reaction layers increased slightly. Meanwhile, the blocky Ti-Cu compounds in the brazing interlayer tended to accumulate and grow. This microstructural evolution and its formation mechanism are discussed. The maximum shear strength was 157 MPa when the joints were brazed with Ag-Cu-Ti at 900 °C for 10 min. The microstructure and bonding properties of the brazed joints were significantly improved when Mo particles were added into the Ag-Cu-Ti. The shear strength reached 310 MPa for joints brazed with 8.0 wt% Mo additive, which was 97% higher than that of joints brazed with single Ag-Cu-Ti filler metal.     

Ag_(70)-Cu_(28)-Ti_2活性钎料真空钎焊AlN-Cu的研究

研究了在真空条件下AlN/Cu活性钎焊的情况,使用的活性焊料是Ag_(70)-Cu_(28)-Ti_2焊片。通过试验可以得到该活性焊料在AlN片上润湿性良好,获得的AlN/Cu接头均达到了气密性要求(漏气速率<1×10~(-10)Pa·m~3/s),平均强度值分别为182 Kg/cm~2(抗弯)和182 Kg/cm~2(抗剪切)。通过扫描电镜及电子探针仪观察了焊层形貌和元素分布,分析了连接强度较高的原因。通过XRD确定了焊接的冶金结合及新相的生成。     

CVD金刚石膜的钎焊界面反应层及微结构

借助扫描电镜和电子探针,分析了金刚石与Ag-Cu-Ti活性钎料界面反应层的微观组织结构、界面新生化合物的形成机理以及焊接工艺条件对界面结构的影响,建立了钎焊接头界面结构物理模型.结果表明,在一定的钎焊工艺条件下,金刚石/钎料界面存在灰色的新生化合物TiC,与TiC相邻的是蜂窝状的TiCu相;接头断裂不仅仅发生在TiC相中,有时断裂也发生在TiCu层.钎焊加热温度、保温时间、钎料层的含Ti量对CVD金刚石厚膜与硬质合金的接头结构模型有重要影响.     

Ag-Cu-Ti钎料在石墨表面的润湿

针对石墨钎焊过程中如何提高钎料在石墨表面的润湿问题，采用真空钎焊，在两组不同的工艺参数条件下，分别取Ti的质量分数W Ti不同的Ag-Cu-Ti钎料，做钎料在石墨表面的润湿性实验。结果表明，W Ti及工艺参数对钎料的润湿性有重要的影响；发现用这种钎料润湿石墨，由于二者热膨胀系数相差悬殊，产生的热应力使石墨产生开裂现象；通过分析对比实验结果，优选了钎料成分及钎焊工艺参数。     

Effect of cerium on microstructure,wetting and mechanical properties of Ag-Cu-Ti filler alloy

Effect of cerium on microstructure,mechanical and wetting properties of Ag-Cu-Ti filler alloy was researched with optical microscopy,scanning electron microscopy and X-ray diffraction.The results indicated that addition of cerium accelerated alloying of the filler alloy,enlarged supercooled region,caused microstructural refinement and dispersed distribution of intermetallic compounds.It resulted in the increase in microhardness and shear strength of Ag-Cu-Ti filler alloy.At the same time,cerium improved wet...     

Microstructure and mechanical properties of BN-Si3N4 and AlON joints brazed with Ag-Cu-Ti filler alloy

AlON was successfully brazed to BN-Si₃N₄ using a Ag-Cu-Ti filler alloy. SEM, TEM and XRD studies revealed that a TiN + TiB₂ + Ti₅Si₃ reaction layer formed adjacent to the BN-Si₃N₄ while a (Cu,Al)₃Ti₃O layer formed adjacent to the AlON. In addition, Ag-Cu eutectic, Cu(s,s) and AlCu₂Ti were observed in the brazing filler. The effect of brazing temperature on the microstructure and mechanical properties of the joints was investigated. As the brazing temperature increased, the reaction layers became thicker, while the thickness of the brazing seam decreased. Meanwhile, the amount and the size of AlCu₂Ti intermetallic compounds decreased. The shear strength of the joints first increased and then dropped with increasing the brazing temperature. A joint with a maximum strength of 94 MPa was obtained when it was brazed at 850 °C for 15 min.     

采用两种银基活性钎料钎焊AlN陶瓷与可伐合金的接头组织与性能

采用Ag-Cu-Ti和Ag-Cu-In-Ti两种活性钎料箔带,分别在860℃/10 min和760℃/10 min两种规范下对AlN与可伐合金(4J29)进行了真空钎焊连接,获得了冶金质量良好的接头. 对接头室温抗剪强度进行了测试,AlN/Ag-Cu-Ti/4J29和AlN/Ag-Cu-In-Ti/4J29两种接头强度分别为126和113 MPa. 微观分析结果表明,两种接头中靠近陶瓷母材附近生成了连续的扩散反应层,结合XRD结果,该层主要由TiN相组成,反应层的厚度对接头强度有影响;钎缝基体区由铜基固溶体、银基固溶体和复杂的Ni(Fe,Co)-Ti化合物组成.