TC4/Ti60合金钎焊接头界面组织及力学性能

采用TiZrNiCu非晶钎料实现了TC4和Ti60异种钛合金的真空钎焊连接,利用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)等分析手段研究了钎焊工艺参数对接头界面组织结构及力学性能的影响. 结果表明,TC4/TiZrNiCu/Ti60钎焊接头的典型界面结构为:TC4/α-Ti+β-Ti+(Ti,Zr)2(Ni,Cu)/Ti60. 随着钎焊温度升高或保温时间延长,片层状α+β相逐渐填充整条钎缝,(Ti,Zr)2(Ni,Cu)相含量减少且分布更加均匀. 接头室温抗拉强度随钎焊温度或保温时间的增加均先增大后减小,在990 ℃/10 min钎焊条件下所获接头抗拉强度达到最大为535.3 MPa. 断口分析结果表明,断裂位于钎缝中,断裂方式为脆性断裂.     

Ag-Cu-Ti钎料高频感应钎焊TiAl/40Cr

采用高频感应加热的方式 ,在Ar气保护条件下 ,用Ag -Cu -Ti钎料实现了TiAl基合金与 4 0Cr钢的钎焊连接 ;采用扫描电镜、电子探针、X射线衍射分析等手段对断口、界面、生成相进行了分析 ,并且测试了接头的抗拉强度。结果表明 ,在界面上有Ti(CuAl) 2 、Ag[s,s]、TiC等反应相生成 ,典型接头界面结构为TiAl/Ti(CuAl) 2 +Ag[s ,s]/Ag[s,s]/TiC/ 4 0Cr) ;断裂位置及接头的抗拉强度随保温时间而变化 ;当钎焊连接温度为 114 3K ,保温时间 0 .9ks时接头抗拉强度值最高 ,达到 2 98MPa,断裂主要发生在Ti(CuAl) 2 层内部     

Ni-34Ti钎料钎焊TiAl合金接头界面结构及性能

采用Ni-34Ti共晶钎料实现了TiAl合金的钎焊连接,分析了TiAl合金钎焊接头的界面结构,重点研究了钎焊温度对接头组织及性能的影响规律.结果表明,Ni-34Ti共晶钎料主要由TiNi相和TiNi3相组成,钎料熔点为1 120 ℃.不同钎焊温度下获得的接头界面组织均呈现对称特征,无气孔和裂纹等缺陷,接头中主要形成了TiNiAl2,B2,TiNiAl和TiNi2Al四种物相.Al元素在钎缝中的快速扩散,促进了钎缝中Ti-Ni-Al三元化合物的形成.钎焊温度为1 180 ℃保温10 min条件下,TiAl合金接头获得了最大的室温抗剪强度87 MPa.剪切过程中,裂纹容易在富含TiNi2Al相的区域产生和扩展,大量脆性TiNi2Al相的存在对接头的性能是有害的.     

化学镀锡钎料钎焊黄铜的接头组织和力学性能

采用化学镀方法在BAg45CuZn钎料表面镀覆微米锡层,并用镀锡银钎料以火焰钎焊工艺连接H62黄铜。借助金相显微镜、扫描电镜(SEM)和X射线衍射仪(XRD)分别分析锡化学镀层、H62黄铜钎焊接头的显微组织和物相,并利用万能拉伸机和SEM表征钎焊接头的抗拉强度和断口形貌。结果表明,锡化学镀层结晶晶粒呈现明显的(110)、(210)择优取向,化学镀锡银钎料连接的接头中母材与钎缝结合紧密,接头组织中富Cu相减少,出现Cu_5Zn_8化合物相。随着基体钎料表面镀锡含量升高,钎焊接头的抗拉强度呈现先升高后降低趋势。在化学镀锡含量为6.0%(质量分数)时,钎焊接头的抗拉强度为353MPa。镀锡前后钎焊接头的拉伸断口均呈现韧性断裂。     

Effect of brazing temperature and brazing time on the microstructure and tensile strength of TiAl-based alloy joints with Ti-Zr-Cu-Ni amorphous alloy as filler metal

An amorphous Ti-37.5Zr-15Cu-15Ni (wt.%) ribbon fabricated by vacuum arc remelting and rapid solidification was used as filler metal to vacuum braze TiAl alloy (Ti-45Al-2Mn-2Nb-1B (at.%)). The effects of brazing temperature and time on the microstructure and strength of the joints were investigated in details. The typical brazed joint major consisted of three zones and the brazed joints mainly consisted of α_2-Ti₃Al phase, α-Ti phase and (Ti, Zr)₂(Cu, Ni) phase. When the brazing temperature varied from 910 °C to 1010 °C for 30 min, the tensile strength of the joint first increased and then decreased. With increasing the brazing time, the tensile strength of the joint increased. The maximum room temperature tensile strength was 468 MPa when the specimen was brazed at 930 °C for 60 min. All the fracture surfaces assumed typical brittle cleavage fracture characteristic. The fracture path varied with the brazing parameter and cracks preferred to initiate at (Ti, Zr)₂(Cu, Ni) phase and propagation path were mainly determined by the content and distribution of α-Ti phase and (Ti, Zr)₂(Cu, Ni) phase.     

Al基钎料钎焊镁合金AZ31B接头的显微组织及力学性能

为了连接变形镁合金AZ31B,以Al基钎料对变形镁合金AZ31B进行高频感应钎焊。采用扫描电镜、X射线衍射仪、X射线能谱等分析钎焊接头的显微组织及钎缝物相,测试钎焊接头的力学性能及显微硬度。结果表明:在钎焊过程中熔融的Al基钎料与固态的AZ31B母材发生强烈的合金化作用,原始钎料中均一的Mg32(Al,Zn)49相在钎焊后完全消失,同时在钎缝中生成α-Mg、β-Mg17(Al,Zn)12相。钎焊搭接接头的平均抗剪强度达到44MPa,对接接头的平均抗拉强度达到71MPa。接头的断裂形式为沿晶脆性断裂,断裂产生在β-Mg17(Al,Zn)12硬脆相处。     

Ti-22Al-25Nb合金板材的钎焊工艺

采用试验手段研究了Ti-22Al-25Nb合金板材的钎焊工艺. 结果表明,当钎焊温度为960 ℃时,Ti₂AlNb合金板材组织中短棒状O相组织发生少量溶解、块状O相组织的晶粒尺寸普遍增大,基体晶粒略粗化,但未出现相转变;随保温时间由15,30和60 min逐渐延长, Ti₂AlNb合金板材室温强度由1 257 MPa减少到1 000~1 100 MPa,但塑性不断提高,室温断后伸长率平均值由2.9%依次提高至3.4%,5.8%及5.0%. 确定出Ti₂AlNb合金板材的钎焊工艺参数为960 ℃/30 min/炉冷,此时相应接头抗剪强度较高,可达152 MPa.     

Al-Si-Cu合金粉末扩散钎焊Al/Cu接头组织及性能

采用Al-Si-Cu合金粉末扩散钎焊铝铜异种金属,采用SEM,EDS和XRD分析接头微观组织结构,结合三元相图分析了接头形成机理,最后检测了接头力学性能.结果表明,在连接温度530℃,保温时间60 min,压力为1MPa时可形成均匀致密的接头,接头中存在大量条状和鱼骨状的Al-Si-Cu共晶组织,中间层与两母材结合界面处的组织结构不同,在靠近铜侧界面存在三种层状金属间化合物,其成分依次为Cu₃Al₂,CuAl和CuAl₂,在靠近铝侧界面存在一个扩散区,没有形成层状金属间化合物.接头的抗剪强度随保温时间的变化而变化,在保温60 min时达到35 MPa.     

TC4钛合金蜂窝板钎焊接头组织性能分析

研究了TC4钛合金蜂窝板的钎焊工艺,试验采用Ti-Zr-Ni-Cu钎料,真空度不低于2×10-3 Pa,钎焊温度为930℃,保温时间为30 min.对焊后试件的钎焊界面组织进行超声无损检测,检测结果表明面板与蜂窝芯钎焊效果极好,未发现有脱焊、虚焊等现象.采用扫描电镜（SEM）和能谱分析（EDS）法进行了试验分析.结果表明,母材和钎料发生相互扩散渗透反应,并出现有新的析出相.该工艺下蜂窝板的界面平均拉脱强度为12.8 MPa,抗剪强度为9.01 MPa,钎焊接头属于脆性断裂.     

Microstructure and Mechanical Properties of 6063 Aluminum Alloy Brazed Joints with Al-Si-Cu-Ni-RE Filler Metal

A new low melting point filler metal, Al-Si-Cu-Ni-RE, was developed for the furnace brazing of aluminum alloy 6063. Flux-assisted brazing was conducted at 560 °C using the new filler metal and AlF₃-CsF-KF flux. Microstructure of the brazed joints were studied by means of SEM, TEM, and EDS. Shear strength and micro-Vickers hardness of joints had been tested. Results show that sound joints could be obtained with the filler metal and the flux. Microstructure characterization of the brazed joint shows dendritic CuAl₂ phase was distributed evenly and Si-phase was spheroidized and refined, which was embedded in CuAl₂ dendrites with modification of rare-earth element. Shear strength test results show that the joints with Al-Si-Cu-Ni-RE filler metal achieved average shear strength of 62.5 MPa, 14.5% more than the shear strength of brazed joints with Chinese HL401 filler metal. The micro-Vickers hardness of joint after T6 treatment is about 83 HV. The hardness of the joints after just brazing and after solution treatment was higher than the hardness of the base metal.     

The Joint Strength and Fracture Mechanisms of TC4/TC4 and TA0/TA0 Brazed with Ti-25Cu-15Ni Braze Alloy

In this paper, Ti-25Cu-15Ni (mass ratio) braze alloys were prepared by vacuum arc melting. Additionally, the TA0 pure titanium and TC4 titanium alloy were brazed with the Ti-25Cu-15Ni braze alloy at 960, 980, 1000, 1020, and 1040 °C. The effects of the braze temperature on the tensile strength of the TA0 and TC4 joints and their fracture mechanisms were studied. The maximum tensile strength of the TA0 joints of 219.9 ± 0.1 MPa was achieved at a brazing temperature of 980 °C, and the maximum tensile strength of the TC4 joints of 832.9 ± 0.1 MPa was achieved at the same brazing temperature. These results indicate that their ideal joint strength is comparable. According to the fractography results of the TA0 joints, a mixed fracture morphology is indicated. The TA0 fracture surface is dominated by cleavage fracture with a small contribution from ductile fracture. The TC4 joint fracture arises from cleavage.     

TC4钛合金真空钎焊接头组织与高温性能

采用高钛含量的粉状Ti-Zr-Ni-Cu钎料实现了TC4钛合金的真空钎焊,分析了不同工艺参数对接头高温(600℃)抗拉强度的影响,并借助扫描电镜(SEM)、能谱分析(EDS)和X射线衍射分析等方法研究了钎焊接头界面组织,确定了界面反应产物及其形态分布.结果表明,在界面反应层中生成五种产物:钛基固溶体、Ti₂Ni,Ti₃Al,CuTi₃,Zr₂Ni.随着钎焊温度和加热时间的增加,接头抗拉强度呈现先增大再降低的趋势,当钎焊温度为950℃和保温时间为30 min时,获得最大高温(600℃)抗拉强度为387 MPa的钎焊接头.     

Vacuum brazing of TiAl-based intermetallics with Ti–Zr–Cu–Ni–Co amorphous alloy as filler metal

An amorphous Ti41.7–Zr26.7–Cu14.7–Ni13.8–Co3.1 (wt%) ribbon fabricated by melt spinning was used as filler to vacuum braze Ti–48Al–2Nb–2Cr (at%) intermetallics. The influences of brazing temperature and time on the microstructure and strength of the joints were investigated. It is found that intermetallic phases of Ti₃Al and γ-Ti₂Cu/Ti₂Ni form in the brazed joints. The tensile strength of the joint first increases and then decreases with the increase of the brazing temperature in the range of 900–1050 °C and the brazing time varying from 3 to 15 min. The maximum tensile strength at room temperature is 316 MPa when the joint is brazed at 950 °C for 5 min. Cleavage facets are widely observed on all of the fracture surfaces of the brazed joints. The fracture path varies with the brazing condition and cracks prefer to initiate at locations with relatively high content of γ-Ti₂Cu/Ti₂Ni phases and propagate through them.     

AlSiNi钎料感应钎焊铝/钢接头的组织和力学性能

借助润湿试验、热分析等手段分析了AlSi12钎料和AlSiNi钎料的钎焊工艺性.使用扫描电镜、能谱分析、力学性能测试等手段分析了AlSi12,AlSiNi钎料钎焊铝/钢接头的组织形貌、断口形貌、相组成和力学性能.结果表明,AlSiNi钎料对钢的润湿性优于AlSi12钎料,但钎料熔化区间稍有扩大;在焊缝/钢界面处,AlSiNi钎料钎焊接头金属间化合物层的厚度为8.1 μm,比AlSi12钎料钎焊接头金属间化合物更薄,分布也更均匀;AlSiNi钎料钎焊接头中的含Ni金属间化合物塑韧性更好,与母材钢的结合力更强,AlSiNi钎料钎焊铝/钢接头抗拉强度高于AlSi12钎料钎焊接头.     

铝合金/不锈钢预涂层钨极氩弧熔钎焊接头的特性

通过在不锈钢表面预涂钎剂层,采用铝硅共晶钎料实现铝合金/不锈钢TIG熔钎焊连接,获得具有熔焊与钎焊双重性质的对接接头,运用OM、SEM、EDS分析接头的微观组织及成分,通过拉伸实验评定接头的力学性能.结果表明:铝母材局部熔化,与液态钎料混合后凝固形成焊缝,焊缝组织主要由α(Al)基体和在晶界析出的Al-Si共晶相组成;不锈钢不发生熔化,液态钎料与不锈钢在界面反应形成不均匀分布的金属间化合物层,最大厚度不超过10 μm,界面上部金属间化合物较厚,呈锯齿状,主要相成分为α(τ5)-Al7.4Fe2Si;界面下部金属间化合物较薄,呈细须状,由α(τ5)-Al7.4Fe2Si+α(Al)混合相构成;接头的平均抗拉强度为90.6 MPa,焊缝/不锈钢界面下部为连接的薄弱环节,成为断裂的起始位置.     

Cu75Pt钎料钎焊Ti60与TC4接头界面组织及性能

采用Cu75Pt钎料实现了Ti60钛合金与TC4钛合金的真空钎焊,采用SEM,EDS,XRD分析了钎焊接头显微结构.结果表明,接头典型组织结构为Ti60/Ti2Cu+α-Ti/Ti2Cu/Ti2Cu+Ti3Pt/Ti2Cu/Ti2Cu+α-Ti/TC4.对不同钎焊温度下获得的接头界面组织结构进行了分析,结果表明,随着钎...     

采用冷喷涂铜涂层做中间层的镁合金与钢共晶接触反应钎焊工艺及接头性能

采用厚度为50 μm的冷喷涂铜涂层作为中间层,研究了连接温度和保温时间对AZ31B镁合金/钢异种金属接触反应钎焊接头剪切强度的影响规律.通过金相显微镜、扫描电镜（SEM）、X射线衍射仪（XRD）、显微硬度和剪切强度试验,研究了AZ31B镁合金/钢钎焊接头界面微观组织和力学性能.结果表明,当连接温度为530℃,保温时间为60 min时,接头剪切强度达到最大值36.9 MPa.AZ31B镁合金/钢钎焊接头界面反应产物主要为Mg₂Cu,α-Mg固溶体和Mg-Cu-Al三元相.Mg-Cu-Al三元相的尺寸和分布,以及08F钢侧是否存在Mg₂Cu共晶相共同决定了接头的强度.由钎焊接头断口可知,最佳工艺参数下断裂方式为脆性断裂与韧性断裂的混合方式.     

Al2O3/SUS304 Brazing via AgCuTi-W Composite as Active Filler

Alumina ceramic (α-Al₂O₃) was brazed to stainless steel (SUS304) using an Ag-Cu-Ti + W composite filler and a traditional active brazing filler alloy (CuSil-ABA). Then, the effects of the presence of W particles and of the brazing parameters on the microstructures and mechanical properties of the brazed joints were investigated. The maximum tensile strength of the joints obtained using Ag-Cu-Ti + W composite filler was 13.2 MPa, which is similar to that obtained using CuSil-ABA filler (13.5 MPa). When the joint was brazed at 930 °C for 30 min, the tensile strengths decreased for both kinds of fillers, although the strength was slightly higher for the Ag-Cu-Ti + W composite filler than for the Ag-Cu-Ti filler. The interfacial microstructure results show that the Ti reacts with W to form a Ti-W-O compound in the brazing alloy. When there are more W particles in the brazing alloy, the thickness of the Ti _X O _Y reaction layer near the alumina ceramic decreases. Moreover, W particles added to the brazing alloy can reduce the coefficient of thermal expansion of the brazing alloy, which results in lower residual stress between the Al₂O₃ and SUS304 in the brazing joints and thus yields higher tensile strengths as compared to those obtained using the CuSil-ABA brazing alloy.     

TiC增强Cf/SiC复合材料与钛合金钎焊接头工艺分析

采用Ag-Cu-Ti-（Ti＋C）混合粉末作钎料,在适当的工艺参数下真空钎焊Cf/SiC复合材料与钛合金,利用SEM,EDS和XRD分析接头微观组织结构,利用剪切试验检测接头力学性能.结果表明,钎焊后钎料中的钛与Cf/SiC复合材料发生反应,接头中主要包括TiC,Ti3SiC2,Ti5Si3,Ag,TiCu,Ti3Cu4和Ti2Cu等反应产物,形成石墨与钛原位合成TiC强化的致密复合连接层.TiC的形成缓解了接头的残余热应力,并且提高了接头的高温性能.接头室温、500℃和800℃高温抗剪强度分别达到145,70,39 MPa,明显高于Cf/SiC/Ag-Cu-Ti/TC4钎焊接头.     

ZrB2-SiC/Inconel 600钎焊接头界面结构与反应机理

采用Ag-28Cu钎料对ZrB2-SiC陶瓷与Inconel 600镍基合金进行真空钎焊连接。利用扫描电镜、能量色散X射线光谱仪研究了钎焊接头界面结构、断口形貌,借助万能试验机测试其剪切强度。结果表明:采用Ag-28Cu钎料对ZrB2-SiC/Inconel 600真空钎焊,可以实现接头冶金结合,接头无裂纹及微孔隙缺陷。界面反应产物为Ni-Fe-Cr合金、Cu(s,s)+Ag(s,s)固溶体、(Cr,Fe)7C3+(Cr,Fe)3C2合金碳化物,结合扩散理论和热力学分析阐述了界面产物形成机理。钎焊接头室温平均剪切强度为32.92 MPa,断裂模式为解理断裂。