用非晶钎料加中间层连接Si3N4陶瓷的试验

采用TiZrCuB非晶钎料并用Cu箔为中间层连接Si3N4陶瓷,研究了钎料成分、钎焊工艺和中间层厚度等对接头室温和高温强度的影响.结果表明:采用Ti40Zr25CuB0.2非晶钎料和70μm厚的Cu箔中间层,在1 323 K,30 min及0.027 MPa压力下钎焊连接Si3N4陶瓷,其接头在室温下的四点抗弯强度最高...     

Ti-Zr-Ni-Cu非晶钎料钎焊Si3N4陶瓷的连接强度

采用Ti40Zr25Ni15Cu20非晶钎料钎焊Si3N4陶瓷,研究钎焊工艺参数对界面反应层和接头连接强度的影响。结果表明:随着钎焊时间的增加和钎焊温度的提高,接头弯曲强度都表现出先上升后下降的趋势;钎焊工艺参数对连接强度的影响主要是由于影响反应层厚度所致;在相同钎焊工艺条件下,采用Ti40Zr25Ni15Cu20非晶态钎料和晶态钎料相比,其接头连接强度提高了84%。     

Ti-Zr-Ni-Cu非晶钎料

根据Si3N4陶瓷钎焊性和非晶形成能力的要求，确定非晶钎料合金成分为Tj40Zr25Nj15Cu20；采用单辊熔体快淬法成功制备了箔带状Ti40Zr25Ni15Cu20钎料合金，并通过X射线衍射、差热分析、电镜线扫描等分析手段证实其为非晶态。试验结果表明，Ti40Zr25Ni15Cu20合金其约化玻璃温度Trg=0．76，过冷液相区△Tx=78K。     

Ti-Zr-Ni-Cu非晶钎料在Si3N4陶瓷上的润湿性研究

针对Si3N4陶瓷的高温活性钎焊要求,设计了高温Ti-Zr-Ni-Cu非晶钎料成分,并采用单辊急冷法成功制备了Ti-Zr-Ni-Cu非晶钎料.对比分析了相同成分的Ti-Zr-Ni-Cu非晶和晶态钎料在Si3N4陶瓷表面的润湿情况.结果表明:在低真空条件下,晶态钎料能够润湿Si3N4陶瓷,非晶钎料却因完全氧化而失效.在5×10-3Pa高真空条件下,非晶钎料的润湿性优于晶态钎料,在研究的Ti-Zr-Ni-Cu非晶钎料中,Ti40Zr25Ni15Cu20非晶钎料对Si3N4陶瓷的润湿性最佳.     

Ti40Zr25Ni15Cu20非晶钎料钎焊Si3N4陶瓷的界面结构及强度

采用Ti40Zr25Ni15Cu20非晶钎料进行了Si3N4陶瓷真空钎焊连接,利用SEM、EDX等微观分析手段,研究了钎焊界面的微观结构,得出界面反应层有两部分组成,接头界面微观结构为Si3N4/TiN/Ti-Si,Zr-Si化合物/钎缝中心;在相同钎焊工艺条件下,研究对比了晶态和非晶态钎料钎焊接头的强度,发现非晶态钎料钎焊的接头强度大大超过用晶态钎料钎焊的接头.     

含锆Cu-P基非晶钎料钎焊紫铜接头的连接强度及微观组织

采用CuP7.7Sn5.4Ni14Si0.2Zr0.04非晶和常规钎料钎焊紫铜,分析了钎料和接头的微观组织及钎焊工艺对接头强度的影响.结果表明,相对于非晶钎料,常规钎料对钎焊工艺的敏感性更大;在相同的试验条件下,采用非晶钎料钎焊的接头强度比常规钎料提高30%以上;非晶钎料看不到明显的相结构,而常规钎料主要由初生（Cu,...     

用非晶钎料加铜层连接Si3N4的界面结构与强度

采用TiZrCuB非晶钎料和铜箔中间层连接Si3N4陶瓷,研究了钎料成分和铜箔厚度对接头界面结构和抗弯强度的影响.结果表明,采用Ti40Zr25CuB0.2非晶钎料和70!m铜箔中间层,在1 323 K×30 min和0.027 MPa压力下连接Si3N4陶瓷,其接头抗弯强度最高为241 MPa;Si3N4陶瓷连接接头界面反应层为TiN,界面微观结构为Si3N4/TiN/Ti-Si+α-Cu+Ti-Zr+Cu-Zr;改变中间层厚度可以调整反应层的结构和厚度;随铜箔厚度增加,Ti-Si化合物层逐渐脱离TiN层被推向钎缝中心并细化呈颗粒状.     

钎焊温度对Cu基非晶钎料钎焊WCuCrZr合金接头性能影响

为了实现降低ITER装置中W/CuCrZr合金钎焊温度的目的,采用甩带技术制备了成分为Cu47Ti33Zr11Ni8Si1(at.%)的宽10mm、厚80μm的均匀连续非晶合金箔带,将此铜基非晶合金作为新型钎料应用于W/CuCrZr合金的钎焊。使用光学显微镜、扫描电镜、X射线衍射仪和显微硬度计测试了接头显微结构、物相组成和显微硬度,对比了不同钎焊温度对接头性能的影响。结果表明：钎焊温度为900℃时,获得的钎焊接头界面接合良好、对母材影响小并且钎缝具有较高的硬度;将铜基非晶钎料应用于W/CuCrZr合金钎焊可以有效的降低钎焊温度。     

Invar合金与Si_3N_4陶瓷钎焊接头界面组织和性能研究

采用Ag Cu Ti活性钎料对Invar合金和Si3N4陶瓷进行钎焊连接,研究了接头界面组织及其形成机制,分析了钎焊工艺参数对接头界面结构和性能的影响。结果表明,钎焊过程中液态钎料中的活性元素Ti与Si3N4陶瓷发生反应,在陶瓷界面形成致密的Ti N和Ti5Si3反应层;同时,Invar合金向液态钎料中溶解,与活性元素Ti反应生成脆性的Fe2Ti和Ni3Ti化合物。钎焊温度和保温时间影响Si3N4陶瓷界面反应层的厚度以及接头中Fe2Ti和Ni3Ti脆性化合物的形成量和分布,这两方面共同决定着接头的抗剪强度。当钎焊温度为870℃,保温15 min时,接头的平均抗剪强度最大值达到92.8 MPa,此时接头的断裂形式呈现沿Si3N4陶瓷基体和界面反应层的复合断裂模式。     

Ti-Ni钎焊Cf/SiBCN陶瓷接头界面组织及机理分析

使用Ti-Ni高温钎料实现C_f/SiBCN陶瓷自身连接.分别研究了钎料成分、钎料箔片叠层方式以及钎焊温度对焊接界面组织形貌的影响.结果表明,在Ni元素含量超过50%且以Ni/Ti/Ni方式叠层得到的接头界面良好,其中Ni元素深入陶瓷基体,与Si元素发生反应,在陶瓷内形成扩散层结构,扩散层内的Ni,Si元素成梯度分布,而Ti元素以化合物的形式弥散分布在焊缝中间部分的钎料层中试验发现,提高钎焊温度有利于Ni元素的扩散,在以Ni/Ti/Ni叠层、Ni元素含量低于50%时,提高钎焊温度至1 300℃得到的接头没有显著裂纹,中间层的钛化合物分布更加弥散.     

Cu-Ni-Ti合金钎料对Si_3N_4陶瓷的润湿与连接

采用座滴法研究了Ｃ４－Ｎｉ－（２７—５６）Ｔｉ合金（原子分数,％,下刚在Ｓｉ３Ｎ４陶瓷上的润湿行为选用真空熔炼合金Ｃｕ３８Ｎｉ３０Ｔｉ３２和Ｃｕ３４Ｎｉ２７Ｔｉ３９作为钎料时,获得的Ｓｉ３Ｎ／Ｓｉ３Ｎ４接头的强度不理想在降低钎料含Ｔｉ量的同时适当降低含Ｎｉ量,重新设计了两种Ｃｕ－Ｎｉ－Ｔｉ（Ｓｉ,Ｂ）合金钎料,并采用膏状形式改善针料成分的均匀性,在１３５３Ｋ,１０ｍｉｎ的针焊条件下获得的Ｓｉ３Ｎ４／Ｓｉ３Ｎ４接头最高三点弯曲强度分别提高至３３８．８和２０６９ＭＰａ,并对Ｓｉ３Ｎ４／Ｓｉ３Ｎ。接头的界面反应进行了分析     

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.     

TiAl基合金的非晶钎焊

利用一种典型的块体非晶成分Zr65Al25Cu27.5(摩尔分数,％),制备成非晶条带焊接TiAl基合金,研究了焊接接头的组织结构和成分分布,并分析了钎焊过程的组织演变规律。研究结果表明,利用Zr65Al25Cu27.5非晶条带可以成功焊接TiAl基合金。焊缝区组织出现了明显的分层现象,从中部到界面区依次是先析出的Zr2Cu型和ZrCu化合物,粗大的ZrCu型化合物和Ti2Al型柱状晶。焊接母材中的Al元素向焊缝发生了扩散,在界面区形成了一层很薄的反应层。     

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.     

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.     

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。     

Microstructure and mechanical properties of Cu/Al joints brazed using (Cu,Ni, Zr,Er)-modified Al—Si filler alloys

To design a promising Al—Si filler alloy with a relatively low melting-point, good strength and plasticity for the Cu/Al joint, the Cu, Ni, Zr and Er elements were innovatively added to modify the traditional Al—Si eutectic filler. The microstructure and mechanical properties of filler alloys and Cu/Al joints were investigated. The result indicated that the Al—Si—Ni—Cu filler alloys mainly consisted of Al(s,s), Al₂(Cu,Ni) and Si(s,s). The Al—10Si—2Ni—6Cu filler alloy exhibited relatively low solidus (521 °C) and liquidus (577 °C) temperature, good tensile strength (305.8 MPa) and fracture elongation (8.5%). The corresponding Cu/Al joint brazed using Al—10Si—2Ni—6Cu filler was mainly composed of Al₈(Mn,Fe)₂Si, Al₂(Cu,Ni)₃, Al(Cu,Ni), Al₂(Cu,Ni) and Al(s,s), yielding a shear strength of (90.3±10.7) MPa. The joint strength was further improved to (94.6±2.5) MPa when the joint was brazed using the Al—10Si—2Ni—6Cu—0.2Er—0.2Zr filler alloy. Consequently, the (Cu, Ni, Zr, Er)-modified Al—Si filler alloy was suitable for obtaining high-quality Cu/Al brazed joints.