Fe3Al合金与A304钢的炉中钎焊试验

采用Cu基、Ag基、Ni基钎料进行Fe3Al合金的炉中钎焊试验,并对钎焊接头进行了外观检查、金相显微组织观察及硬度检测。结果表明：炉中钎焊Fe3Al合金与A304钢是可行的,其中BAg50CuZn银基钎料和QNi-3镍基钎料能获得较好的钎焊效果;在BASSOCuZn和QNi-3钎料的接头区发生了钎料组元与母材的深度扩散反应,呈现良好的冶金结合效果;QNi-3钎抖的接头区具有较高的硬度,表明其具有较高的强度和较好的高温性能,能较好地发挥Fe3Al合金的使用性能。     

Fe3Al合金与A3O4钢的炉中钎焊试验

采用Cu基、Ag基、Ni基钎料进行Fe3Al合金的炉中钎焊试验,并对钎焊接头进行了外观检查、金相显微组织观察及硬度检测.结果表明:炉中钎焊Fe3Al合金与A3O4钢是可行的,其中BAg50CuZn银基钎料和QNi-3镍基钎料能获得较好的钎焊效果;在BAg50CuZn和QNi-3钎料的接头区发生了钎料组元与母材的深度扩散反应,呈现良好的冶金结合效果;QNi-3钎料的接头区具有较高的硬度,表明其具有较高的强度和较好的高温性能,能较好地发挥Fe3Al合金的使用性能.     

ME20M镁合金的炉中钎焊试验研究

采用铜箔作中间层和BAl88SiMg钎料对ME20M镁合金进行了真空炉中钎焊试验研究.结果表明,采用铜箔为中间层和BAl88SiMg钎料在真空炉中钎焊ME20M镁合金时,均存在较大的溶蚀倾向,且采用BAl88SiMg钎料钎焊ME20M镁合金时,钎焊温度和钎料量对溶蚀的影响更加显著;采用铜箔作中间层在525℃钎焊温度下得到的接头外观质量较好,接头区有高硬度的脆性相CuMg- 2生成,而在540℃钎焊温度下,由于发生严重溶蚀而不能焊合.     

Mo中间层对防止Al_2O_3/Kovar钎焊接头裂纹的作用(英文)

为避免Al2O3陶瓷／Kovar接头裂纹的产生,在Kovar表面磁控溅射金属Mo,并使用Ti-Cu-Ni活性钎料进行钎焊试验。通过扫描电镜和能谱对界面微观组织和成分进行了分析。结果表明,当溅射钼中间层的厚度为14．2μm时,在Al2O3／Kovar界面处,Mo中间层可阻碍Kovar中Fe元素与钎料中Ti元素相互反应产生脆性FexTiy金属间化合物,防止了界面处裂纹的生成。     

Al-Si-Cu-Zn急冷钎料钎焊铝及铝合金的界面结构及强度

采用Al70Si7.5Cu20Zn2.5和Al65Si10Cu20Zn5两种急冷钎料钎焊L2纯铝和6063铝合金,研究钎焊接头的界面微观结构和力学性能.结果表明,急冷钎料钎焊接头由母材、界面区和钎缝中心组成.界面区为αAl固溶体,钎缝中心组织为αAl固溶体 θ(Al2Cu)相 Si相.采用Al65Si10Cu20Zn5急冷钎料钎焊的接头抗剪强度均高于Al70Si-7.5Cu20Zn2.5急冷钎料钎焊的接头强度;匹配氯化物钎剂钎焊的接头强度均高于氟化物钎剂.在相同的工艺条件下,采用急冷钎料钎焊的L2纯铝接头,其抗剪强度都明显高于相应的常规钎料,其增加值在40%左右.     

Al2O3P/Al复合材料钎焊的试验研究

针对Al2O3P/Al复合材料，选用铝基HL401作钎料，选用QJ201为钎剂，在炉中氩气保护下进行钎焊．试验研究了其焊接工艺参数对接头强度的影响。试验表明：采用炉中氩气保护下钎焊Al2O3P/Al复合材料完全可行，用所选择的合适的钎料和钎剂，在优化的工艺参数条件下可获得优质的焊接接头。     

钎料对YG8合金与低碳钢焊接性能的影响

采用两种铜基钎料HL841(CuZnMnSnNiCo合金)和HL105(CuZnMn合金)对YG8硬质合金和低碳钢进行真空钎焊,并对比研究了焊缝的微观组织、元素扩散情况及接头抗拉强度。研究表明:两种钎料与硬质合金结合处形成互溶区,HL105形成的互溶区宽度大概为1μm,而HL841形成的互溶区宽度约为3μm;HL841钎料中的Co、Ni等元素有利于形成Fe-Co-Ni单相固溶体,同时钎焊过程中钎料中的Co还能缓解硬质合金中粘结相Co的扩散流失。这些原因使得采用HL841焊接的试样的接头力学性能优于HL105。     

采用Ni基钎料和Cu中间层真空钎焊W/CuCrZr的接头组织和性能研究

以20μm厚的纯Cu片作为中间层,采用20μm厚的非晶态Ni基钎料箔在在900、930、950℃下保温10min真空钎焊W和CuCrZr合金。采用SEM和EDS分析了钎焊接头的界面形貌,检测钎焊接头的剪切强度及显微硬度。结果表明,中间层Cu与母材CuCrZr合金一侧界面结合良好,在CuCrZr合金一侧形成了钎焊热影响区;钎料与W母材界面处形成了反应层,在W母材侧有微裂纹。随着钎焊温度的升高,W侧裂纹增多,造成接头性能的迅速恶化。W和CuCrZr的钎焊温度最好控制在930℃以下。以纯Cu片为中间层,采用Ni基钎料钎焊W和CuCrZr的过程,实质上是Ni与Cu、W互相扩散并反应生成化合物层和固溶体的过程。钎焊接头的最佳剪切强度为144MPa,断裂主要发生在W母材及W与反应层之间的界面。钎缝区域的显微硬度随钎焊温度的升高而降低,CuCrZr合金焊接热影响区的硬度高于其母材。     

SiC_P/Al复合材料的钎焊工艺研究

采用Zn98Al和Zn72.5Al两种Zn-Al药芯钎料对SiCP/Al复合材料进行氩气保护钎焊试验,研究了钎焊温度和保温时间对接头剪切强度及显微组织的影响。结果表明,用这两种钎料在氩气保护炉中钎焊SiCP/Al复合材料,可以获得质量良好的钎焊接头。对Zn98Al钎料,当温度为490℃、保温45min时可获得剪切强度为71.01MPa的钎焊接头;而Zn72.5Al钎料,在温度为560℃、保温11 min时可获得剪切强度为63.71MPa的钎焊接头。两种钎料的钎焊接头显微硬度均略低于母材。两种接头钎缝区的XRD相结构分析发现,钎缝中都只存在α(Al)和β(Zn)两相;接头断口扫描观察显示,接头整体呈韧性断裂特征。     

中间层厚度对复合钎料钎焊接头强度的影响

采用中间层Cu合金厚度不同的3种CT861复合钎料钎焊低碳钢,研究不同钎料钎焊接头的组织和强度。结果表明:中间层Cu合金厚度不同,复合钎料钎焊低碳钢接头抗剪强度不同,抗剪强度随中间层厚度增加而降低。中间层Cu合金厚度为0.075 mm时复合钎料钎焊接头抗剪强度为214 MPa,Cu合金厚度为0.1 mm时复合钎料钎焊接头抗剪强度为170 MPa,Cu合金厚度为0.15 mm时复合钎料钎焊接头抗剪强度为137 MPa。可根据强度需要,选用不同厚度中间层的CT861复合钎料。     

Fluxless laser brazing of aluminium alloy to galvanized steel using a tandem beam – dissimilar laser brazing of aluminium alloy and steels

Tandem beam brazing with aluminium filler metal (BA4047) was conducted in order to develop the fluxless laser brazing technique of aluminium alloy (AA6022) to galvanized steels (GA and GI steels). Laser powers of tandem beam and offset distance of preheating beam from the root to the steel base metal were varied. Sound braze beads could be obtained by optimizing the preheating and main beam powers under the offset distances of 0–1 mm. A small amount of zinc remained at the braze interface between galvanized steels and the braze metal. The reaction layer consisting of Fe–Al intermetallic compounds was also formed at the steel interface, and the thickness of reaction layer could be predicted during the laser brazing (thermal cycle) process based on the growth kinetics with the additivity rule. The metal flow analysis of the melted filler metal on joints revealed that wettability and spreadability of the filler metal on the GI steel joint were superior to those on the GA steel joint. The fracture strength of the lap joint attained approx. 55–75% of the base metal strength of aluminium alloy. It was concluded that fluxless laser brazing could be successfully performed by using a tandem beam because the zinc coat layer acted as the brazing flux.     

Brazing of A5056 aluminium alloy with the aid of ultrasonic vibration using Ag filler metal

In order to produce a high strength brazed joint of A5056 aluminium alloy containing magnesium of about 5 mass%, the authors applied a flux-free brazing method with the aid of ultrasonic vibration to the aluminium alloy by selecting pure Ag foil as brazing filler metal and examined the effect of brazing conditions on the joint properties. The main results obtained in this study are as follows.

At a brazing temperature of 570°C, just above the eutectic point of Al–Ag binary system, application of ultrasonic vibration for 4.0 s provided the brazed joint with the maximum tensile strength and the strength decreased with the application time. When the brazing temperature was varied from 550 to 580°C and the application time of ultrasonic vibration was kept constant at 4.0 s, the joint brazed at 560°C attained the maximum tensile strength and fractured in the base metal. It was found that using a pure Ag foil as brazing filler metal successfully brazed A5056 aluminium alloy and the joint strength was equivalent to that of the base metal. Fracture of the joint was prone to occur along the (Al₃Mg₂ + Al solid solution) phase with high hardness formed at the grain boundary of the base metal. The amount of the hard (Al₃Mg₂ + Al solid solution) phase increased with the ultrasonic application time and the brazing temperature. It seemed that the increase of the hard (Al₃Mg₂ + Al solid solution) phase mainly caused the brazed joint strength to decrease.     

Diode laser brazing of aluminium alloy to steels with aluminium filler metal

Abstract

Diode laser brazing of aluminium alloy (A5052) to interstitial free steel (IF steel) or type 304 stainless steel (SUS304) was conducted using aluminium filler metal (BA4047) with Nocolock flux. The processing parameters of laser power, wire feed rate and travel speed were varied. The strength of lap joints of A5052 on steels was evaluated by tensile shear test. The joint strength of A5052/steels was increased with increasing laser power and reached the maximum strength, more than approximately 80% of the A5052 base metal strength, at a laser power of 1300 W. Voids and incomplete penetration of filler metal were observed at the A5052/braze layer interface when the laser power was below 1100 W. The Fe–Al intermetallic compounds were formed at the steel/braze layer interfaces and grew drastically when the laser power exceeded 1300 W. Superior brazability of A5052/steels was found at brazing conditions corresponding to a temperature of filler metal droplet of 1050–1250 K.     

填充泡沫Ti/AlSiMg的SiC陶瓷钎焊接头的组织与性能

为丰富SiC陶瓷钎焊所用钎料的设计思路,提出了一种泡沫Ti/AlSiMg新型复合钎料,通过Ti元素的溶入提高钎料与SiC陶瓷之间的界面结合力,利用泡沫Ti与Al基钎料之间的界面反应获得原位增强的钎缝,从而提升接头力学性能. 采用钎焊温度700 ℃、保温时间60 min和焊接压力10 MPa进行SiC陶瓷真空钎焊,利用光学显微镜、扫描电镜、能谱分析、X射线衍射、电子探针和万能试验机对接头组织、成分和性能进行分析,探索泡沫Ti/AlSiMg复合钎料在SiC陶瓷钎焊中的可用性. 结果表明,填充泡沫Ti/AlSiMg复合钎料所得接头结构为SiC/Al/Ti(Al,Si)₃/Ti(Al,Si)₃原位增强Ti基钎缝/ Ti(Al,Si)₃/Al/SiC,断裂发生在铝合金界面层和SiC陶瓷之间,Ti元素的溶入提高了铝合金界面层与SiC陶瓷之间的界面结合力,接头抗剪强度达111 MPa.     

Interfacial structure and bond strength of ultrasonic brazed Al–304 stainless steel dissimilar joints

Abstract

A filler alloy (Zn–14 at.-%Al) was used to join aluminium to 304 type stainless steel by ultrasonic brazing at 673 K for different ultrasound application times. Different reaction layers could be observed at the interface, containing Fe–Al, Fe–Zn, and Al–Zn solid solutions. As the amount of these solid solutions increased at the interface, there was a gradual improvement in the joint bond strength. The maximum bond strength of 146 MPa was obtained for the Al–304 joint brazed at 673 K for 3 s ultrasound application time. A critical remaining thickness of the filler alloy after ultrasonic application improves the interfacial joining. Extending the ultrasound application time beyond 3 s causes a bulk escape of the brazing alloy from the interface and leads to a direct interaction between aluminium and 304, which increases the possibility of forming intermetallics, and consequently decreases the joint bond strength.     

Interfacial structure and joint strengthening in arc brazed galvanized steels with copper based filler

1 Introduction Arc brazing is a brazing method that the specimens are heated by arc[1]. It is the generic terms of GMA brazing and GTA brazing[2], and has both the characteristics of brazing and welding. Compared with traditional arc fusion welding, the s…     

瞬间液相扩散焊与钎焊主要特点之异同

从焊接进程、凝固、氧化物的破碎、中间层与钎料的区别、接头组成、脆性相的形成与消除、压力的作用、接头强化机理等方面总结分析了瞬间液相扩散焊与钎焊的区别。强调指出了下述关键点 :(1)中间层的选取是获得两种不同焊接方法接头的首要前提 ;(2 )在钎焊中侧重点是润湿性 ,它是保证接头获得一定强度的首要前提与主要手段 ;(3 )在瞬间液相扩散焊过程中 ,除了润湿性之外 ,更为关注的是降熔元素的扩散。中间层中降熔元素向母材的持续扩散是TLP接合中液态区增宽、破碎氧化膜、等温凝固、均匀化现象的本质原因 ;降熔元素向母材的充分扩散及由此而出现的中间层成分的合理改变是TLP焊接成败的命脉     

SiCp/Al复合材料与Fe36Ni合金超声波钎焊

利用超声波钎焊方法使用ZnAlSi钎料实现了Fe36Ni合金与45%SiC_p/2024Al和55%SiC_p/A356两种复合材料的连接,并得到由SiC颗粒增强的复合焊缝.通过扫描电镜、能谱等方法对焊缝的微观结构以及断口形貌进行了观察,对接头的压剪强度进行了测试,分析了Fe36Ni与两种复合材料钎焊接头微观组织和接头强度的差异.结果表明,在Fe36Ni与两种复合材料的钎缝中,钎料与两侧母材界面均形成良好的冶金结合,SiC颗粒均匀分布于焊缝中.Fe36Ni与45%SiC_p/2024Al的接头抗剪强度为110~145 MPa,Fe36Ni与55%SiC_p/A356的接头抗剪强度为75~85 MPa.Fe36Ni与45%SiC_p/2024Al的接头断裂位置为钎缝中,而Fe36Ni与55%SiC_p/A356的接头断裂位置位于Fe36Ni与钎料的界面上.     

Fe_3Al合金与A304钢的TIG焊试验研究

采用TIG焊方法,分别选择9Cr-1Mo钢焊丝、A347焊丝和Inconel82Ni基合金焊丝作填充材料对Fe3Al合金与A304不锈钢进行焊接试验,并对接头质量进行了检测分析。结果表明:三种填充焊丝的焊缝中均有裂纹产生,并且在Fe3Al合金的热影响区还出现了微裂纹;采用Cr-Mo钢焊丝时,溶池金属沿Fe3Al母材基体结晶长大,接头区组织较均匀,而采用Ni基焊丝时,Fe3Al侧存在界线明显的熔合区。     

钎焊温度对TC4与Ti3Al-Nb合金钎焊接头组织的影响

采用50Ti-20Zr-20Ni-10Cu粉末钎料对Ti3Al-Nb合金与TC4合金进行真空钎焊,通过SEM、EDS、电子探针及拉伸试验研究不同钎焊温度下钎焊接头的显微组织及性能特征.结果表明,钎焊温度升高钎焊接头强度并不提高;不同温度下钎焊接头中靠近TC4合金基体边界处均生成魏氏体组织,随温度升高魏氏体组织粗化程度加剧;整个钎焊接头中Ti3Al-Nb合金基体与钎料的反应程度弱于TC4合金基体.