用Cu箔中间层瞬间液相连接SiCP/Al 复合材料的界面现象与连接强度

采用Cu箔作中间层,在温度为853K的条件下进行了SiCp/Al复合材料的瞬间液相（Transient Liquid-Phase bonding,TLP)连接,用扫描电镜观察了连接界面微观形貌,测定了接头的剪切强度,着重研究了连接时间和压力对界面结构和强度的影响。研究表明,不加压连接时,由于在界面处形成纯金属带,且氧化膜也难以去除,接头强度较低,约为母材强度的48%,接头剪切强度随连接时间延长而增高,连接时施加0.2MPa的压力即可显著提高接头强度,达到母材强度的70%,且强度随连接时间变化不大,试验还发现,用Cu箔中间层无压瞬间液相连接小增强相颗粒、高体积百分含量的SiCp/AlMMCs时,接头界面区域没有发现颗粒偏聚,本文对此进行了理论分析。     

SiCP颗粒增强Al基复合材料的瞬间液相连接

采用Ni箔和Cu/Ni/Cu多层箔作中间层在923K进行了SiC颗粒增强铝基复合材料的瞬间液相连接.研究表明,无压连接时,接头强度随保温时间延长有所增高,但界面处会存在纯金属(无增强颗粒)区域和氧化物夹杂,是导致接头强度不高的主要原因.加压TLP连接则能有效改善界面组织和接头性能.采用Cu/Ni/Cu多层箔作中间层加压连接时接头强度可达189.6MPa,约为母材强度的85%.本文对压力的作用和复合材料TLP连接界面特性进行了讨论.     

SiCP/Al复合材料的真空扩散钎焊

文中采用Al/Cu/Al复合箔扩散钎焊SiC_P/Al复合材料,采用SEM,EDS,XRD分析接头界面组织,研究了钎焊温度对接头界面组织及力学性能的影响,并结合Al-Cu二元相图分析接头形成机制.结果表明,固定连接压力为1 MPa,保温时间为10 min,当钎焊温度从590℃升至640℃,接头界面产物由Al₂Cu+αAl共晶组织转变为断续的Al₂Cu金属间化合物,Al-Cu液相向两侧母材扩散的距离增加,接头的抗剪强度呈现先增大后减小的变化趋势.当钎焊温度为620℃,保温时间为10 min,连接压力为1 MPa时,接头的抗剪强度达到最大值69 MPa.     

SiCP颗粒增强Al基复合材料的瞬间液相连接

采用Ni箔和Cu/Ni/Cu多层箔作中间层在923K进行了SiC颗粒增强铝基复合材料的瞬间液相连接。研究表明,无压连接时,接头强度随保温时间延长有所增高,但界面处会存在纯金属（无增强颗粒）区域和氧化物夹杂,是导致接头强度不高的主要原因。加压TLP连接则能有效改善界面组织和接头性能。采用Cu/Ni/Cu多层箔作中间层加压连接时接头强度可达189．6MPa,约为母材强度的85％。本文对压力的作用和复合材料TLP连接界面特性进行了讨论。     

Ti/Cu/Ti部分瞬间液相连接Si_3N_4的界面反应和连接强度

用Ti/Cu/Ti多层中间层在 12 73K进行氮化硅陶瓷部分瞬间液相连接 ,实验考察了保温时间对连接强度的影响。用SEM ,EPMA和XRD对连接界面进行微观分析 ,并用扩散路径理论 ,研究了界面反应产物的形成过程。结果表明 :在连接过程中 ,Cu与Ti相互扩散 ,形成Ti活度较高的液相 ,并与氮化硅发生反应 ,在界面形成Si3N4 /TiN/Ti5Si3 Ti5Si4 TiSi2 /TiSi2 Cu3Ti2 (Si) /Cu的梯度层。保温时间主要是通过影响接头反应层厚度和残余热应力大小而影响接头的连接强度     

SiC颗粒增强铝基复合材料的瞬间液相连接

铝基复合材料采用Cu箔、Ni箔和Cu/Ni/Cu多层箔作中间层进行瞬间液相连接。研究了保温时间和压力对铝基复合材料接头组织和性能的影响。研究发现，加压能有效改善铝基复合材料接头组织和性能；采用Cu/Ni/Cu多层箔作中间层时铝基复合材料接头强度最高，达189.6MPa，约为母材强度的84.6%。     

Ti／Cu／Ti部分瞬间液相连接Si3N4的界面反应和连接强度

用Ti/Cu/Ti多层中间导在1273K进行氮化硅陶瓷部分瞬间液相连接,实验考察了保温时间对连接强度的影响,用SEM,EPMA和XRD对连接界面进行微观分析,并用扩散路径理论,研究了界面反应产物的形成过程,结果表明：在连接过程中,Cu与Ti相互扩散,形成Ti活度较高的液相,并与氮化硅发生反应,在界面形成Si3N4/TiN/Ti5Si3 Ti5Si4 TiSi2/TiSi2 Cu3Ti2(Si)/Cu的梯度层,保温时间主要是通过影响接头反应层厚度和残余热应力大小而影响接头的连接强度。     

铝基复合材料的Al-Cu合金中间层瞬间液相扩散连接

采用Al—Cu合金作为中间层研究了铝基复合材料(Al2O3p／6061Al)瞬间液相扩散连接接头的组织与力学性能。研究结果表明，在Al—Cu／A12O3p／6061Al接头中无明显的增强相偏聚区和增强相贫化区，且接头成分分布较为均匀；在Al—C。合金中间层厚度30μm、连接温度600℃、连接时间30min条件下，接头抗剪强度为130～140MPa,较Cu／A12O3p／6061Al接头抗剪强度提高45％。因此，采用Al—Cu中间层是改善铝基复合材料接头力学性能的有效途径。     

Cu中间层SiCp/Al MMCs TLP扩散连接过程分析

采用铜箔作中间层,在连接温度为853 K、无压的条件下进行了瞬间液相连接,对TLP扩散连接过程及其动力学模型进行了分析,并对试验结果进行了的验证.结果表明TLP扩散连接理论模型和试验结果之间还存在着一些差异,对等温凝固过程还需要进一步探讨.分析认为,AlMMCs中大量的晶界、亚晶界、位错等短路扩散通道的存在,直接影响TLP连接过程及其动力学.     

Si3N4/Ti/Cu/Ni/Cu/Ti/Si3N4二次部分瞬间液相连接强度

采用Ti/Cu／Ni中间层对Si3N4陶瓷进行二次部分瞬间液相(PTLP)连接，研究连接工艺参数对Si3N4／Ti/Cu／Ni连接强度的影响，同时研究了连接强度随试验温度的变化规律。结果表明，在该试验条件下，室温连接强度随着二次连接温度的提高和二次保温时间的延长而提高，改变连接工艺参数对Si3N4／Ti/Cu／Ni二次PTLP连接界面反应层厚度无明显影响；连接强度在试验温度400℃时达到最大，随后随试验温度升高，连接强度降低，但在800℃前，其高温强度具有很好的稳定性。     

Transient Liquid-Phase Diffusion Bonding of Aluminum Metal Matrix Composite Using a Mixed Cu-Ni Powder Interlayer

In the present study, the transient liquid-phase diffusion bonding of an aluminum metal matrix composite (6061-15?wt.% SiCp) has been investigated for the first time using a mixed Cu-Ni powder interlayer at 560?°C, 0.2?MPa, for different holding times up to 6?h. The microstructure of the isothermally solidified zone contains equilibrium precipitate CuAl₂, metastable precipitate Al₉Ni₂ in the matrix of ??-solid solution along with the reinforcement particles (SiC). On the other hand, the microstructure of the central bond zone consists of equilibrium phases such as NiAl₃, Al₇Cu₄Ni and ??-solid solution along with SiC particles (without any segregation) and the presence of microporosities. During shear test, the crack originates from microporosities and propagates along the interphase interfaces resulting in poor bond strength for lower holding times. As the bonding time increases, with continual diffusion, the structural heterogeneity is diminished, and the microporosities are eliminated at the central bond zone. Accordingly, after 6-h holding, the microstructure of the central bond zone mainly consists of NiAl₃ without any visible microporosity. This provides a joint efficiency of 84% with failure primarily occurring through decohesion at the SiC particle/matrix interface.     

化学镀Ni-P-W/Al2O3 复合镀层与NdFeB基体的结合强度研究

采用化学镀方法,在NdFeB磁性材料表面施镀Ni-P-W/Al2O3复合镀层,观察了镀层表面的微观形貌,测定了镀层的相组成,并且对基体与镀层间的结合强度进行了测试.结果表明:形成了胞状交叠的致密Ni-P-W/Al2O3复合镀层,纳米Al2O3颗粒弥散分布于Ni-P-W合金中;Al2O3颗粒与Ni-P-W共沉积有利于提高镀层与基体间的结合强度,镀液中Al2O3的质量浓度为5～10 g/L时,基体与镀层间的结合强度最好.     

Interfacial Phenomena in Al/Al,Al/Cu,and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions

The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)_EUT, (Al-Zn)_EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)_EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.     

金属基复合材料过渡液相(TLP)扩散焊中间层设计的改进

为防止复合材料过渡液相（TLP）扩散焊焊缝中心区域出现增强相偏聚，归纳总结了5种中间层设计的改进方法：（1）适当减小中间层厚度；（2）采用合金型中间层；（3）加覆（镀）阻挡层；（4）中间层材质的优化；（5）减少液态金属的挤出量。评述了各种方法的优缺点。     

金属基复合材料过渡液相(TLP)扩散焊中间层设计的改进

为防止复合材料过渡液相(TLP)扩散焊焊缝中心区域出现增强相偏聚,归纳总结了5种中间层设计的改进方法:(1)适当减小中间层厚度;(2)采用合金型中间层;(3)加覆(镀)阻挡层;(4)中间层材质的优化;(5)减少液态金属的挤出量。评述了各种方法的优缺点。     

Atom Diffusion Behavior and Bonding Strength of Ag/Cu Composite Interface

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Interfacial Reactions and Bonding Strength of Sn-xAg-0.5Cu/Ni BGA Solder Joints

The present study details the microstructure evolution of the interfacial intermetallic compounds (IMCs) layer formed between the Sn-xAg-0.5Cu (x = 1, 3, and 4 wt.%) solder balls and electroless Ni-P layer, and their bond strength variation during aging. The interfacial IMCs layer in the as-reflowed specimens was only (Cu,Ni)₆Sn₅ for Sn-xAg-0.5Cu solders. The (Ni,Cu)₃Sn₄ IMCs layer formed when Sn-4Ag-0.5Cu and Sn-3Ag-0.5Cu solders were used as aging time increased. However, only (Cu,Ni)₆Sn₅ IMCs formed in Sn-1Ag-0.5Cu solders, when the aging time was extended beyond 1500 h. Two factors are expected to influence bond strength and fracture modes. One of the factors is that the interfacial (Ni,Cu)₃Sn₄ IMCs formed at the interface and the fact that fracture occurs along the interface. The other factor is Ag₃Sn IMCs coarsening in the solder matrix, and fracture reveals the ductility of the solder balls. The above analysis indicates that during aging, the formation of interfacial (Ni,Cu)₃Sn₄ IMCs layers strongly influences the pull strength and the fracture behavior of a solder joint. This fact demonstrates that interfacial layers are key to understanding the changes in bonding strength. Additionally, comparison of the bond strength with various Sn-Ag-Cu lead-free solders for various Ag contents show that the Sn-1Ag-0.5Cu solder joint is not sensitive to extended aging time.     

WC_p/2024Al基复合材料的腐蚀机理

采用动电位阳极极化法对体积分数为11.4%WCp/2024Al基复合材料及其基体合金在3.5%NaCl水溶液中的耐蚀性能进行研究。结果表明,由于WC颗粒的加入,提高了WCp/2024Al基复合材料的腐蚀速度。通过对恒电位极化后试样观察发现,WCp/2024Al基复合材料腐蚀机理为富Cu相作为阴极区与其周围的贫Cu区作为阳极区构成电偶腐蚀以及WC颗粒与基体间的协同腐蚀作用。这种双重的电偶腐蚀致使复合材料腐蚀速度加快。     

Cu/Al合金异种材料复合管电阻压焊接头连接特性分析

利用电阻压焊进行Cu/Al合金异种材料复合管的焊接试验,分析了接头微观组织与界面主要元素的分布特征。结果表明,接头中Cu元素大量扩散溶入Al基体中,形成有害的CuAl2金属间化合物,但是,电阻压焊过程中外加顶锻力使结合区产生剧烈塑性变形,能破碎粗大CuAl2金属间化合物并细化接头熔合区晶粒,有利于改善接头的结合性能,获得优质焊接接头。     

溶胶-凝胶法制备Al2O3弥散强化铜基复合材料

弥散强化铜基复合材料制备的关键是如何向铜基体中引入弥散强化相,以及控制弥散相的粒径、分布等。本研究采用溶胶-凝胶法(Sol-Gel)与热压烧结相结合的方法制备Al2O3弥散强化铜基复合材料,该方法制备的Al2O3弥散强化铜基复合材料的导电率达到79.32%IACS,硬度(HB)127.3,软化温度在900℃以上。