微连接用碳基纳米颗粒增强无铅复合钎料的研究新进展

综合评述含碳纳米管、石墨烯纳米片等碳基纳米颗粒增强微连接用无铅复合钎料的研究现状,介绍了碳纳米管、石墨烯纳米片、富勒烯、金属改性碳纳米管(石墨烯纳米片)等增强相对无铅钎料和钎焊接头组织与性能的影响。简述了无铅复合钎料的制备方法、熔化特性、导电性、润湿性、力学性能和无铅复合钎料焊点可靠性等,指出了碳基纳米颗粒增强无铅复合钎料存在的问题、解决措施及发展趋势。     

无钯镀镍碳纤维增强Sn-3.0Ag-0.5Cu复合钎料的制备

采用化学镀法在碳纤维表面制备无钯镍镀层,用粉末冶金法制备了以镀镍碳纤维为增强相的Sn-3.0Ag-0.5Cu复合钎料,借助于SEM、EDS、OM等检测手段对其微观组织进行分析,研究镀镍碳纤维含量对复合钎料微观组织和基本性能的影响。结果表明:镀镍碳纤维主要分布在复合钎料的晶界处;随着复合钎料中镀镍碳纤维含量的增加,其弥散度逐渐降低,熔点变化不大;当镀镍碳纤维含量(质量分数)大于1%时,镀镍碳纤维在晶界处的团聚现象严重,复合钎料的电阻率显著升高。添加1%的镀镍碳纤维有助于减小液态复合钎料在助焊剂界面和Cu基板处的表面张力,降低钎料基体的电流密度,使得复合钎料的润湿性提高,电阻率有所降低。     

合金元素对70% SiC_p/Al复合材料钎料性能的影响

采用正交试验法,研究了Cu,Si,Mg以及Ni元素的含量变化对Al-Cu-Si-Mg-Ni钎料熔点、润湿性的影响规律,并通过扫描电镜观察分析了钎料的显微组织.结果表明,影响钎料熔点的三个主要因素依次为:Mg元素的含量、Al-Cu-Si三元共晶反应程度和Ni元素的含量.随着镁含量增加,钎料的熔点降低,润湿性提高,但过量的镁使焊缝凝固后组织疏松.当镁含量一定时,η≈(Si/Cu)/(Si+Cu)与0.06越接近则三元共晶反应进行程度越大,钎料熔点越低.当Mg元素的含量和Al-Cu-Si三元共晶反应程度一定时,镍含量增加,钎料熔点降低.在焊缝组织方面,沿晶界析出的粗大的块状硅相会增大接头脆性;在部分区域偏聚的Si元素,形成富硅相,在其周围常有气孔形成;弥散分布的白亮色针状θ(Cu Al2)相也会在一定程度上降低接头性能;而具有面心立方结构的α固溶体(Al-Cu固溶体、Al-Cu-Si固溶体和Al-Si固溶体)基体则使钎料具有优良的力学性能.     

含碳纳米管的Sn-58Bi钎料的制备及其钎焊性

采用球磨—低温冶炼法制备了不同碳纳米管含量的Sn-58B i-CNTs钎料,借助SEM,EDS和DSC等分析手段研究了碳纳米管在钎料合金中的形态以及碳纳米管对Sn-58B i合金焊点拉脱强度的影响.结果表明,经过钎料低温冶炼后,碳纳米管能够部分加入到Sn-58B i合金中形成复合钎料;Sn-58B i-0.03%CNTs复合钎料在焊盘上的润湿性得到了提高,且微量碳纳米管的加入对钎料熔点的影响不大;碳纳米管在焊点中弥散分布使钎料的组织得到细化,并通过对焊点微观断裂机制的影响,提高焊点的可靠性.     

Sn改性Ti-Zr-Cu-Ni钎料的微观组织和力学性能

采用自制Ti-Zr-Cu-Ni-Sn钎料钎焊TA2钛合金,研究了不同Sn元素含量改性Ti-Zr-Cu-Ni钎料的熔化特性、微观组织及物相、润湿及熔蚀性、接头拉伸强度。研究表明,Sn含量增加,Ti-Zr-Cu-Ni-Sn钎料固、液相线温度基本升高,但温度差值基本变窄,可更好地抑制钎焊界面脆性化合物形成。Ti-Zr-Cu-Ni-5Sn钎料组织由Ti、Zr基体和晶体相构成,Sn倾向与Ti、Zr结合形成Ti₂Sn₃、Ti₆Sn₅、Zr₅Sn₃等低熔点共晶相。Sn≤1.5%时,随Sn含量增加,钎料对TA2钛合金的润湿性逐渐变差;继续增加Sn,钎料润湿性改善,添加5%Sn的钎料对基体润湿最佳。添加5%Sn并降低Cu、Ni总量的改性钎料对TA2钛合金熔蚀减弱。相同钎焊工艺下,添加5%Sn接头的强度和塑性均有提升。钎焊温度升高,Ti-Zr-Cu-Ni钎料产生更多强化物相,致接头强度大幅提升,而Ti-Zr-Cu-Ni-5Sn钎料产生的含Sn物相强化作用对接头强度提升有限;相...     

颗粒增强复合钎料钎焊TiAl合金接头界面结构及性能

采用纳米Si3N4颗粒增强的AgCuTi复合钎料(AgCuTiC)实现了TiAl合金的钎焊连接.利用SEM,EDS及XRD等分析方法确定了TiAl/AgCuTiC/TiAl接头的典型界面结构为TiAl/AlCu2Ti/Ag(s,s)+TiN+ Al4Cu9+Ti5Si3.结果表明,钎焊过程中从TiAl母材溶入液相钎料的活性钛与复合钎料中纳米Si3N4颗粒发生反应,在钎缝中形成了细小的颗粒状TiN,Ti5Si3及Al4Cu9化合物增强的银基复合材料组织.银基复合材料的形成不仅提高了钎缝自身的强度,而且通过降低钎缝的线膨胀系数缓解了接头残余应力,并最终改善了钎焊接头的性能.当采用增强相含量为3％的AgCuTiC钎料在880℃保温5min条件下钎焊时,接头室温平均抗剪强度最高为278 MPa,比采用AgCuTi钎料提高40％.     

真空电子器件用V-B系列钎料研究

采用真空-充氩熔炼V-B系列钎料,并通过球磨技术制成焊料粉末.实验表明:V-B系列钎料的真空钎焊性能优良;V-B系列块状钎料瞬间熔化并快速铺开,流动性好,润湿性好,表面均匀.V-B-Pd块状钎料的熔点为1730℃,V-B块状钎料的熔点为1740℃;V-B粉末钎料铺展均匀,有明显的润湿环,钎料铺展面积约占基体面积的3/4,钎料的熔点为1560℃.     

AgCuTi活性钎料的研究进展

AgCuTi系活性钎料是连接金属众多陶瓷及碳材料的理想钎料，解决了很多传统钎焊的难题。列举了常用商业AgCuTi的牌号及成分，简要分析了AgCuTi钎料的润湿性及影响AgCuTi润湿性的重要因素，综述了AgCTi活性钎料的一般制备方法与技术，以及AgCuTi活性钎料连接的典型应用与研究进展。     

热解还原法制备镀镍ZrO2增强低银SnAgCu系复合钎料及其钎焊

本文采用热分解-还原法制备镀镍ZrO2增强相,粉末冶金法制备镀镍ZrO2增强Sn1.0Ag0.5Cu复合钎料,研究了ZrO2纳米颗粒表面金属化以及其对Sn1.0Ag0.5Cu复合钎料的微观结构、材料性能及钎焊接头的影响。结果表明:经机械预处理的ZrO2粒径减小、团聚降低;采用热分解-还原法成功地制备出了镀镍ZrO2增强相,Ni粒子以8-11 nm间距均匀附着于ZrO2表面,ZrO2(02)和Ni(11)界面呈半共格关系;添加适量镀镍ZrO2对Ni/ZrO2-Sn1.0Ag0.5Cu复合材料的熔点、电阻率影响不大,提高了润湿性和抗拉强度,在镀镍ZrO2增强相添加量为0.7 wt.%时Ni/ZrO2-Sn1.0Ag0.5Cu复合钎料抗拉强度、钎焊接头剪切强度均达峰值,较基体材料的相比提高了43.3%、40%。随着Ni-ZrO2增强相的添加,复合钎料钎焊接头的断裂位置由界面IMC层向过渡区的近钎缝侧移动,断裂机制由韧-脆混合断裂逐渐转为韧窝为主的韧性断裂。     

Ni含量对304/Sn-8Sb-4Cu-xNi/304钎焊接头组织与剪切性能的影响

研究了Ni含量对Sn-8Sb-4Cu-xNi(x=0, 0.5, 1和2,质量分数)钎料熔点和微观组织的影响,用Sn-8Sb-4CuxNi钎料对304不锈钢进行钎焊连接,分析了接头的界面组织与剪切性能.结果表明,添加不同含量的Ni后,Sn-8Sb-4Cu-xNi均为近共晶钎料,其熔点约为245℃;Sn-8Sb-4Cu钎料组织由α相基体、Sb₂Sn₃+Cu₆Sn₅+Sn复合相和Cu₆(Sn,Sb)₅相组成.添加Ni元素后,钎料中块状Cu₆(Sn,Sb)₅转变为细小、均匀分布的(Cu,Ni)₆(Sn,Sb)₅.当Ni含量小于1%时,随Ni含量的增加,钎料中的复合相和(Cu,Ni)₆(Sn,Sb)₅相均增加;当Ni含量为2%时,钎料中的复合相和(Cu,Ni)₆(Sn,Sb)₅相均减少,但(...     

Microstructure and mechanical properties of the SiC/Nb joint brazed using AgCuTi+B4C composite filler metal

The residual stress is considered to be the driving force for the failure of ceramic/metal brazing joint. In this paper, the residual stress in a SiC/Nb joint is alleviated by using AgCuTi+B₄C composite brazing filler. SEM, EDS and XRD are applied to characterised the microstructure of the joint, which is determined to be SiC/Ti₃SiC₂/Ag(s,s)+Cu(s,s)+TiB+TiC/TiCu+ Nb(s,s)/Nb. The effects of the B₄C strengthening phase mass fraction and the brazing temperature on the microstructure and the mechanical properties of the joint are investigated. It is found that the reaction products between B₄C and the brazing filler (TiB whisker and TiC particles) uniformly distribute inside the joint if the mass fraction of the B₄C is not higher than 1.5 wt% and when the amount of B₄C reaches 2 wt%, the reaction products begin to agglomerate. With the rising of the brazing temperature, the thickness of the Ti₃SiC₂ reaction layer next to the ceramic increases and when the brazing temperature reaches 910 °C, another reaction layer of Ti₅Si₃ can be found adjacent to the Ti₃SiC₂ reaction layer. The strength of the joint first increases and then decreases with the increase of both the strengthening phase and the brazing temperature. The highest shear strength of the joint reaches 98 MPa when the joint is achieved at 890 °C using AgCuTi+1.5 wt%B₄C brazing filler.     

热浸镀锡铜磷钎料的性能

以Cu93P钎料为基体,在其表面热浸镀锡,制备CuPSn钎料,采用扫描电镜、万能力学试验机、显微硬度计、差热分析仪、箱式电阻炉和体视显微镜分析锡镀层的界面形貌,钎料的抗拉强度、显微硬度、熔化温度和润湿性。结果表明：在Cu93P钎料表面热浸镀锡过程中,液态锡与钎料发生了界面反应,生成Cu₆Sn₅金属间化合物,即钎料基体与锡镀层形成良好的冶金结合;随着热浸镀温度的升高和时间的延长,CuPSn钎料的抗拉强度和显微硬度均呈降低趋势,抗拉强度的降低源于界面处产生的Cu₆Sn₅脆性化合物和孔洞,显微硬度的降低源于热浸镀的去应力退火作用;Cu93P钎料表面热浸镀锡可降低钎料的熔化温度,提高钎料的润湿性,Cu93P钎料表面热浸镀5.20%（质量分数）锡之后,Cu88.16P6.64Sn5.20在纯铜板上的润湿铺展面积比基体Cu93P钎料增加43.15%。     

两种Pd-Ni基高温钎料在Si3N4陶瓷上的润湿性

采用座滴法研究了两种钎料PdNi-(15～22)v和PdNi-(16～24)Cr在Si3N4陶瓷上的润湿性.结果表明,两种钎料的熔点及润湿性均有很大差别,PdNi-(16～24)Cr钎料对Si3N4陶瓷的润湿铺展良好.PdNi-(16～24)Cr钎料与Si3N4陶瓷形成的扩散反应层中,Cr元素主要分布在扩散反应层区域,根据各元素所占比例,Cr元素主要与母材扩散出的N元素形成Cr2N相.由于Cr原子向母材界面扩散,从而改善了钎料的润湿性.     

Microstructure and mechanical properties of C/C composite joint brazed with Ni-based filler

The novel Ni-based brazing filler was used to join C/C composites. When brazing temperature increased from 1080 to 1100 °C, the wetting angle decreased from 23° to 14°, and the brazing filler had good wettability on the surface of C/C composites. The brazing seam of the brazed joint consisted of Ni(s,s) and Cr₃C₂ phases. As brazing temperature increased, lots of Cr₃C₂ phases were generated at the bonding interface, and the thick reaction layer was formed. When brazing temperature was 1120 °C, the shear strength of C/C joint reached the maximum value of 31.5 MPa. The fracture path extended in the C/C matrix close to the bonding interface.     

Wettability and interfacial reactions of PdNi-based brazing fillers on C-C composite

The wettability and interfacial reactions of four kinds of PdNi-based brazing fillers on C-C composite were studied with the sessile drop method.The results showed that the wettability of these brazing fillers was improved with the increase of Cr content. Cr distributed at the interface of brazing filler/C-C composite and the formation of Cr23C6 phase was speculated.In the interface between Ni-33Cr-24Pd-4Si brazing filler and C-C composite,element Cr reacted with C-C to form Cr-C reaction layer.Pd together ...     

Development of Ag based brazing filler metal with low melting point

Abstract

This study was carried out to develop cadmium free silver based brazing filler metals that meet the following requirements. First, they have to have a melting point lower than that of BAg-1 brazing filler metal. Second, they have to have not only good wetting characteristics and the ability to produce a sound joint with excellent mechanical properties but also plastic formability. Using the calculated phase diagrams on Ag–Cu–Zn–Sn quaternary system alloys, the authors selected several alloys with a possibility of meeting the above requirements. The melting point and other properties, such as hardness and brazeability of the selected alloys, were evaluated. As a result, the authors successfully developed silver based brazing filler metals that have a low melting point below ～600°C and meet the above requirements by adding a small amount of indium as an alloying element into the Ag–Cu–Zn–Sn quaternary system alloy. The newly developed brazing filler metals are slightly inferior in wetting characteristics to BAg-1; however, the brazing filler metal containing ～3 mass-% indium element showed wetting characteristics comparable to those of BAg-1. Furthermore, the new brazing filler metals could produce joints with a high tensile strength equivalent to ～83% of that of a joint brazed using BAg-1.     

腐蚀对复合银钎料的影响

采用恒温浸泡腐蚀、电化学腐蚀、润湿铺展测试和扫描电子显微镜(SEM)、万能力学试验机等手段研究了复合银钎料中钎剂与钎料合金的腐蚀及钎料腐蚀对钎焊性能的影响。结果表明,银钎料处于含水钎剂环境中,会被钎剂腐蚀。在钎料中加入1.5%~2.5%的Sn,缩小了Ag-Cu-Zn合金中Ag-Zn相与Cu-Zn相之间的电位差,降低了两相之间的微电池效应,Sn细化Ag-Cu-Zn钎料中的共晶相,降低银钎料发生腐蚀的敏感性;用被腐蚀的银钎料钎焊钢,钎焊接头抗拉强度损失,在钎料中添加Sn可抑制损失程度。