TC4钛合金/304不锈钢异种材料蜂窝结构钎焊工艺

采用Ti-37.5Zr-15Cu-10Ni和Ag-28Cu两种钎料分别对TC4钛合金面板/304不锈钢蜂窝芯异种材料蜂窝结构进行了钎焊,对钎焊界面组织和蜂窝结构的力学性能进行了对比分析. 结果表明,Ti基钎料与304不锈钢蜂窝芯箔材界面润湿反应性能较差且Ti基钎料钎缝显微硬度较高,导致钎焊界面强度低,蜂窝拉伸力学性能差. Ag基钎料与304不锈钢蜂窝芯箔材和TC4面板均发生显著的界面反应,钎焊温度830 ℃,保温时间10 min时,蜂窝抗拉强度为10.35 MPa,呈蜂窝芯破坏特征. Ag基钎料蜂窝抗拉强度明显优于Ti基钎料结果,适用于TC4钛合金面板/304不锈钢蜂窝芯异种材料蜂窝钎焊.     

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.     

LaNd对Ti-13Zr-21Cu-9Ni钎料铺展性及TC4接头性能的影响

为了优化Ti-13Zr-21Cu-9Ni钎料性能、获得一种性能优良的Ti合金接头,向Ti-13Zr-21Cu-9Ni钎料中添加了稀土元素LaNd. 以应用普遍的TC4合金为母材,通过真空炉、场发射扫描电镜、X射线衍射仪等设备研究了稀土元素LaNd对Ti-13Zr-21Cu-9Ni钎料铺展性能及TC4接头性能的影响. 结果表明,随着LaNd添加量的增加,Ti-13Zr-21Cu-9Ni-xLaNd钎料的铺展面积和Ti-13Zr-21Cu-9Ni-xLaNd/TC4钎焊接头的抗剪强度先增大后减小. 当LaNd添加量为0.3%时,Ti-13Zr-21Cu-9Ni-xLaNd钎料铺展面积最大,最大值为0.74 cm2,较基体提高了88.8%;当LaNd添加量继续增加时,生成的Cu₅La相会使钎料的铺展性能大幅降低. Ti-13Zr-21Cu-9Ni-xLaNd/TC4钎焊接头抗剪强度在LaNd添加量为0.3%时达到最大值,为157.1 MPa,较基体提高了45.2%. LaNd的最佳添加量应该为0.3%.     

Microstructure and high-temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints

The microstructure evolution and high-temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints under different welding parameters were studied. The results show that the weld fusion zone of TC4/TA15 dissimilar welded joints consists of coarsened β columnar crystals that contain mainly acicular α′ martensite. The heat affected zone is composed of the initial α phase and the transformed β structure, and the width of heat affected zone on the TA15 side is narrower than that on the TC4 side. With increasing temperature, the yield strength and ultimate tensile strength of the TC4/TA15 dissimilar welded joints decrease and the highest plastic deformation is obtained at 800 °C. The tensile strength of the dissimilar joints with different welding parameters and base material satisfies the following relation (from high to low): TA15 base material > dissimilar joints > TC4 base material. The microhardness of a cross-section of the TC4/TA15 dissimilar joints reaches a maximum at the centre of the weld and is reduced globally after heat treatment, but the microhardness distribution is not changed. An elevated temperature tensile fracture of the dissimilar joints is located on the side of the TC4 base material. Necking occurs during the tensile tests and the fracture characteristics are typical when ductility is present in the material.     

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.     

Interfacial Microstructure Evolution and Shear Strength of Titanium Sandwich Structures Fabricated by Brazing

The corrugated sandwich structure, consisting of a CP Ti (commercially pure titanium) core between two Ti-6Al-4V face sheets, was brazed using pasty Ti-37.5Zr-15Cu-10Ni as filler alloy, at the temperature of 870°C for 5, 10, 20, and 30 min. The effect of brazing time on the microstructure and elemental distribution of the brazed joints was examined by means of SEM, EDS, and XRD analyses. It was found that various intermetallic phases were formed in the brazed joints, following a brazing time of 5 min, and their contents were decreased by the increment of brazing time, while prolonged brazing time resulted in a fine, acicular Widmanstätten microstructure throughout the entire joint. In addition, shear testing was performed in the brazed corrugated specimens in order to indirectly assess the quality of the joints. The debonding between CP Ti and Ti-6Al-4V was observed in the specimen brazed for 5 min and the fracture of the CP Ti corrugated core occurred after 30 min of brazing time. Additionally, when brazed for 10 min or 20 min, brittle intermetallic compounds in the joints and the grain growth of the base metal were controllable. Therefore, the sandwich structures failed without debonding in the joints or fracture within the base metal, demonstrating a good combination of strength and ductility.     

Brazing of 6061 aluminum alloy/Ti-6Al-4V using Al-Si-Cu-Ge filler metals

Al-8.4Si-20Cu-10Ge and mixed rare-earth elements (Re) containing Al-8.4Si-20Cu-10Ge-0.1Re filler metals were used for brazing of 6061 aluminum alloy/Ti-6Al-4V. The addition of 20 wt.% copper and 10 wt.% germanium into the Al-12Si filler metal lowered the solidus temperature from 586 °C to 489 °C and the liquidus temperature from 592 °C to 513 °C. The addition of 0.1 wt.% rare-earth elements into Al-8.4Si-20Cu-10Ge alloy caused remarkable Al-rich phase refinement and transformed the needle-like Al₂Cu intermetallic compounds into block-like shapes. Shear strengths of the 6061 aluminum alloy/Ti-6Al-4V joints with the two brazing filler metals, Al-8.4Si-20Cu-10Ge and Al-8.4Si-20Cu-10Ge-0.1Re, varied insignificantly with brazing periods of 10-60 min. The average shear strength of the 6061 aluminum alloy/Ti-6Al-4V joints brazed with Al-8.4Si-20Cu-10Ge at 530 °C was about 20 MPa. Rare-earth elements appeared to improve the reaction of the Al-8.4Si-20Cu-10Ge filler metal with Ti-6Al-4V. The joint shear strength of the 6061 aluminum alloy/Ti-6Al-4V with Al-8.4Si-20Cu-10Ge-0.1Re reached about 51 MPa.     

钛合金TC6与TC11高频感应钎焊工艺

以B-Ti57CuZrNi-S为钎料,在氩气保护气氛下对TC6/TC11钛合金进行高频感应钎焊工艺实验研究。采用光学显微镜(OM)、扫描电镜(SEM)及能谱分析(EDS)等测试方法,分析气体保护流量、流态以及工艺参数对焊接界面形貌、接头组织及元素分布的影响,并测试接头的抗拉强度。结果表明,钎焊界面主要由富Ti的β-Ti固溶组织和Cu-Ti、Ni-Ti以及(Cu,Ni)Ti/Zr组成的金属间化合物相组成。钎焊接头的抗拉强度随钎焊温度的升高或保温时间的延长,呈现先升高后降低的趋势,接头最高强度可达433MPa。TC6/TC11钛合金高频感应钎焊优化工艺参数带为:焊接温度910℃~930℃,保温时间120~150 s,Ar气保护流量1 MPa。     

Brazing of TiBw/TC4 composite and Ti60 alloy using TiZrNiCu amorphous filler alloy

TiB_w/TC4 composite was brazed to Ti60 alloy successfully using TiZrNiCu amorphous filler alloy, and the interfacial microstructures and mechanical properties were characterized by SEM, EDX, XRD and universal tensile testing machine. The typical interfacial microstructure was TiB_w/TC4 composite/β-Ti + TiB whiskers/(Ti, Zr)₂(Ni, Cu) intermetallic layer/β-Ti/Ti60 alloy when being brazed at 940 °C for 10 min. The interfacial microstructure evolution was influenced strongly by the diffusion and reaction between molten fillers and the substrates. Increasing brazing temperature decreased the thickness of brittle (Ti, Zr)₂(Ni, Cu) intermetallic layer, which disappeared finally when the brazing temperature exceeded 1020 °C. Fracture analyses indicated that cracks were initialized in the brittle intermetallic layer when (Ti, Zr)₂(Ni, Cu) phase existed in the brazing seam. The maximum average shear strength of joints reached 368.6 MPa when brazing was conducted at 1020 °C. Further increasing brazing temperature to 1060 °C, the shear strength was decreased due to the formation of coarse lamellar (α+β)-Ti structure.     

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...     

SP700/TC4钛合金蜂窝夹层结构钎焊工艺分析

采用非晶态Ti-Zr-Cu-Ni箔带钎料对SP700/TC4钛合金蜂窝结构进行钎焊工艺研究,分析了钎焊温度和保温时间对钎焊接头组织和力学性能的影响. 结果表明,当钎焊温度在875～890 ℃之间变化时,随温度升高,钎焊接头中元素扩散更为充分,接头拉脱强度持续增长;在890 ℃下保温2～4 h不同时长进行钎焊,接头的拉脱强度先逐渐增加,在保温时间为3.5 h时达到最大值,随后逐渐降低. 获得SP700/TC4钛合金蜂窝结构的较优钎焊工艺为890 ℃/3.5 h,该工艺下钎焊接头的室温拉脱强度、三点弯曲强度、平面压缩强度、L及W方向抗剪强度分别达到14.64,224.05,11.21,4.43及3.76 MPa,破坏部位均为TC4蜂窝芯.     

TC4/TA17异种钛合金激光焊接接头显微组织和力学性能

研究TC4/TA17异种钛合金激光焊接接头的显微组织和力学性能。结果表明,TC4/TA17异种钛合金激光焊接头焊缝的显微组织为片状α′马氏体,TC4侧靠近母材的热影响区和TA17侧靠近母材的热影响区只发生α相向β相转变,TC4侧靠近焊缝的显微组织为残余α相+针状α′马氏体,TA17侧靠近焊缝的显微组织为残余α相+片状α′马氏体。TC4/TA17异种钛合金激光焊接头的显微硬度呈不对称分布,焊缝的显微硬度最高,TA17母材显微硬度最低。TC4/TA17异种钛合金激光焊接接头断裂在TA17母材,断口呈现韧性断裂形貌。     

基于高频感应钎焊的TC4钛合金层积成形研究

为研发一种以TC4薄板直接作为金属造形材料的快速成形技术,选用自制的Ti基快冷薄带钎料,结合高频感应钎焊技术,制备了层积成形试样。通过对试样的力学性能、钎焊接头界面的显微组织进行分析。结果表明,由非晶态钎料制备的层积成形试样抗拉强度高于TC4,而晶态钎料的低于TC4。2种钎料成形试样的钎焊接头组织均由(Ti,Zr)_2(Cu,Ni)+(Ti,Zr)_(ss)共晶组织和富Zr的α-Ti固溶体构成,钎缝的拉伸断口呈人字纹形貌,为脆性断裂。     

Ag-Cu+WC复合钎料钎焊ZrO2陶瓷和TC4合金

采用新型Ag-Cu+WC复合钎料进行ZrO₂陶瓷和TC4合金钎焊连接,探究了接头界面组织及形成机制,分析了钎焊温度对接头界面结构和力学性能的影响. 结果表明,接头界面典型结构为ZrO₂/TiO+Cu₃Ti₃O/TiCu+TiC+W+Ag_(s,s)+Cu_(s,s)/TiCu₂/TiCu/Ti₂Cu/TC4. 钎焊过程中,WC颗粒与Ti发生反应,原位生成TiC和W增强相,为Ti-Cu金属间化合物、Ag基和Cu基固溶体提供了形核质点,同时抑制了脆性Ti-Cu金属间化合物的生长,优化了接头的微观组织和力学性能. 随钎焊温度的升高,接头反应层的厚度逐渐增加,WC颗粒与Ti的反应程度增强. 当钎焊温度890 ℃、保温10 min时,复合钎料所得接头抗剪强度达到最高值82.1 MPa,对比Ag-Cu钎料所得接头抗剪强度提高了57.3%.     

Ti-37.5Zr-15Cu-10Ni钎焊钼的钎缝组织分析

采用Ti-37.5Zr-15Cu-10Ni非晶钎料真空钎焊钼,获得Mo/Mo钎焊接头,研究钎焊过程液态钎料与母材的相互作用. 结果表明,液态Ti-37.5Zr-15Cu-10Ni钎料与钼发生扩散–溶解,即母材钼向钎料中的溶解和钎料组分向母材的扩散. 随钎焊温度的升高,钼向钎料中溶解量增加,凝固后钼主要固溶在Ti基固溶体内;随钎焊温度的升高,发生钎料组分向母材晶间的扩散,当温度为900 ℃时,发生显著的晶间渗入现象. 为得到良好的钎焊接头,避免母材过量溶解和晶间渗入的发生,Ti-37.5Zr-15Cu-10Ni钎料真空钎焊钼温度不宜高于900 ℃.     

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.     

Ag-Cu钎料钎焊ZTA陶瓷与TC4钛合金

使用Ag-Cu钎料钎焊ZTA陶瓷与TC4钛合金,利用扫描电子显微镜(SEM)、能谱分析仪(EDS)和X射线衍射仪(XRD)等设备分析了钎焊接头界面组织,阐明了反应机理,并研究了钎焊温度对接头界面组织和力学性能的影响. 结果表明,钎焊接头的界面结构为ZTA陶瓷/TiO+Ti₃(Cu,Al)₃O/Ag(s,s)/Ti₂Cu₃/TiCu/Ti₂Cu/α+β-Ti/TC4合金. 随着钎焊温度的升高,钎缝中Ag基固溶体层变薄,Ti-Cu金属间化合物层变厚,当钎焊温度达到890 ℃时,Ti-Cu金属间化合物几乎占据整了个钎缝区域. 随着温度的升高,接头抗剪强度先增大后减小,在钎焊温度为890 ℃时,接头的室温抗剪强度达到最大值,其值为43.2 MPa.     

AgCu钎料钎焊TC4钛合金与QCr0.8铬青铜接头界面结构及性能

采用AgCu28钎料实现了TC4钛合金与QCr0.8铬青铜的真空钎焊,利用SEM, EDS以及XRD等分析方法确定TC4/AgCu/QCr0.8接头的典型界面结构为TC4钛合金/CuTi +Cu3Ti2 +CuTi2/Ag(s,s) +Cu4Ti/Ag(s,s)+Cu(s,s)/QCr0.8铬青铜. 研究了工艺参数对接头组织和性能的影响. 结果表明,随着钎焊温度和保温时间的增加,钎缝中银铜共晶组织减少,钛铜化合物增多. 接头抗剪强度随钎焊温度的升高先增加后降低,在钎焊工艺参数为890 ℃/0 min时,获得最大抗剪强度449 MPa.保温时间的延长使得接头脆性钛铜化合物增多,接头性能下降,因此随保温时间延长接头抗剪强度显著降低.     

Vacuum brazing of TZM alloy to ZrC particle reinforced W composite using Ti-28Ni eutectic brazing alloy

Reliable brazing of TZM alloy and ZrC particle reinforced (ZrC_p) W composite was achieved in this study by using Ti-28Ni eutectic brazing alloy. The typical interfacial microstructure of TZM/Ti-28Ni/ZrC_p-W brazed joint consisted of a Ti solid solution (Ti(s, s)) layer, a continuous Ti₂Ni layer and a diffusion layer mainly composed of W particles and (Ti, Zr)C particles. With an increase of brazing temperature, more ZrC particles and W particles entered the molten brazing alloy, which broadened the brazing seam and diminished the Ti₂Ni layer, resulting in the disappearance of the Ti₂Ni layer eventually. Meanwhile, more Ti(s, s) stripes were observed on the TZM side. The presence of continuous Ti₂Ni intermetallic phase and Ti(s, s) stripes structure in joints deteriorated the joining properties, which resulted in the formation of brittle fracture under shear test. In addition, the fracture path was related to the brazing temperature, and cracks initiate and propagate in the continuous Ti₂Ni layer at lower temperatures. However, the fracture path tended to be located at the TZM substrate close to the interface between TZM and the brazing seam when the brazing temperature exceeded 1040 °C. The optimal room temperature shear strength reached 120.5 MPa when brazed at 1040 °C for 10 min and the fracture surface exhibited cleavage fracture characteristics, and the shear strength at high temperature of 800 °C for the specimens with highest shear strength at room temperature reached 77.5 MPa.     

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.