SiC陶瓷与TC4钛合金反应钎焊的研究

采用Ｃｕ箔对常压烧结的ＳｉＣ陶瓷与ＴＣ４钛合金进行了接触反应钎焊,并对接头的微观组织,形成机理和室温强度进行了研究。结果表明,利用Ｃｕ箔可以在低于其熔点的温度实现ＳｉＣ与ＴＣ４钛合金的连接。接头界面具有明显的层状结构,即由Ｔｉ－Ｃｕ－Ｓｉ合金层,Ｔｉ－Ｃｕ合金层和富Ｔｉ的Ｔｉ－Ｃｕ－Ａｌ合金层组成。在１２７３Ｋ的条件下连续５ｍｉｎ,接头室温关照切达到１８６ＭＰａ。     

金属熔滴在基片上方和基片下方的润湿性研究

为了研究重力对润湿过程的影响,设计了2组润湿实验方案,即Zr41.2Ti13.8Cu12.5Ni10.0Be22.5合金熔体在SiC基片上方和Zr41.2Ti13.8Cu12.5Ni10.0Be22.5合金熔体在SiC基片下方.结果表明:当合金熔滴在SiC基片下方时,在重力的作用下,熔滴的高度随温度的升高先增大后减小;合金熔滴在SiC基片上方时,熔滴的高度只是随温度的升高而减小.无论是在连续升温情况下还是在等温润湿过程中,Zr41.2Ti13.8Cu12.5Ni10.0Be22.5合金熔体在SiC基片上方时的润湿角都要更小一些.说明在地面重力场环境中,熔滴与基片的不同空间方位对液态Zr41.2Ti13.8Cu12.5Ni10.0Be22.5合金与固态SiC基片之间的润湿角有很大影响.     

SiC陶瓷与TiAI合金的真空钎焊

采用Ag-Cu-Ti钎料对常压烧结的SiC陶瓷与TiAl金属间化合物进行了真空钎焊,并对接头的微观组织和室温强度进行了研究。结果表明,利用Ag-Cu-Ti钎料可以实现SiC与TiAl的连接;接头界面具有明显的层状结构,即由Ti-Cu-Si合金层、富Cu相与富Ag相的双相层和Ti-Al-Cu合金层组成;在1173K和10min的钎焊条件下,接头室温剪切强度达到173MPa。     

Copper-Ti3SiC2 composite powder prepared by electroless plating under ultrasonic environment

In this article, a new type of Cu-Ti3SiC2 composite powder prepared using the electroless plating technique was introduced. The initial Ti3SiC2 particles are 11 μm in diameter on an average. The Cu plating was carried out at middle temperature （62-65℃） with the application of ultrasonic agitation. The copper deposition rate was determined by measuring the weight gain of the powder after plating. It has been found that the pretreatment of Ti3SiC2 powder is very important to obtain copper nanoparticles on the surface of Ti3SiC2 The optimum procedure before plating aimed to add activated sites and the adjustment of the traditional composition of the electroless copper plating bath could decelerate the copper deposition rate to 0.8 gm/h. X-ray diffraction （XRD） indicates that the chemical composition of the plating layer is copper. SEM images show that the surface of the Ti3SiC2 particles is successfully coated with continuous copper layer. The wetting property between the copper matrix and Ti3SiC2 can be improved so as to increase the interfacial strength.     

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.     

Cu含量对钛镍基非晶复合材料的组织和力学性能的影响

采用铜模吸铸法成功制备Cu含量不同但直径相同的TiNi基非晶复合材料试样(Ti0.5Ni0.5)100-XCuX,研究Cu含量在(X=0,10,15,20,25,30,35,40)情况下对TiNi基非晶复合材料组织和力学性能的影响。试验结果表明,在铜的含量x=20时,合金断裂强度和塑性应变都很高,此时合金具有最优良的综合性能。随着x值的增大,(Ti0.5Ni0.5)100-XCuX合金的非晶形成能力呈现一个从上升、降低再到上升的波形变化,但总体呈现降低趋势。Cu元素在TiNi基复合材料中的适量添加(x=25左右时)可以提高Ti基非晶材料的塑性,但添加量较多(x>30)时,既不能提高合金的非晶形成能力又不能提高合金的强度。在x=15时,合金有最高的断裂强度2440MPa,达到了1471MPa的较高的屈服强度值,且其产生了17.15%塑性应变,在X=25时,合金塑性应变有所提高,塑性变形达到了21.35%。     

碳化硅复合材料与碳钢钎焊接头的抗剪强度及微观结构

采用磁控溅射镀膜技术对碳/碳化硅复合材料(C/SiC)表面进行镀Ti金属化,以AgCu₂₈为钎料,无氧铜为中间层与碳钢进行钎焊连接. 研究无氧铜中间层、Ti膜厚度和钎焊温度对接头组织形貌和力学性能的影响. 结果表明,采用无氧铜中间层可有效降低接头的残余应力,提高接头强度,并阻挡C/SiC复合材料中的Si元素在钎焊过程中扩散至碳钢侧,防止了碳钢界面FeSi_x恶性反应层的形成. 在试验范围内,钛膜厚度和钎焊温度与接头抗剪强度之间均存在峰值关系. 860 ℃,3 μm Ti膜接头平均抗剪强度最高,达到25.5 MPa. 由剪切试样碳钢侧断口,可观察到大量平行断口方向的碳纤维和碳纤维脱粘坑. 断裂发生在C/SiC复合材料内部距界面约300 μm处. C/SiC界面反应产物以Ti₅Si₃为主,含少量TiC. 钎缝中有TiCuSi相生成.     

Nanostructured bulk glassy Cu_(60)Zr_(30)Ti_(10) alloy with high strength and good ductility in cast state

1　INTRODUCTIONSinceaseriesofmetallicbulkglassyalloyswithexpectedmechanicalpropertiesandhighglassformingabilityhavebeenfound[13] ,particularattemptshavebeendonetoimprovethemechanicalpropertiesoftheglassyalloystomeetengineeringapplications .Bycrystallizingthemetallicglasses ,nanostructuredal loyscontainingnanocrystallinephasesandglassyma trixwereobtainedandthemechanicalpropertiesofthealloyswereenhancedbyhomogeneousdispersionofnanoscalemetallic particlesintheAl [4 ,5] ,Fe Ni [6 ] andMg [7]…     

Cf/SiC复合材料与钛合金(Ti-Zr-Cu-Ni)+W复合钎焊分析

在适当的工艺参数下,用(Ti-Zr-Cu-Ni)+W复合钎料真空钎焊Cf/SiC复合材料与钛合金,采用SEM,EDS和XRD分析接头组织结构,利用剪切试验检测接头的力学性能.结果表明,钎焊时复合钎料中的钛、锆与Cf/SiC复合材料反应,在Cf/SiC复合材料与连接层界面生成Ti3SiC2,Ti5Si3和少量TiC(ZrC)化合物的混合反应层,在连接层与钛合金界面形成Ti-Cu化合物扩散层.增强相钨粉能有效缓解接头的残余热应力,提高接头力学性能,在连接温度930℃,保温时间20 min的工艺条件下,增强相钨粉含量为15%(体积分数)时,接头抗剪强度最高为166 MPa.     

Si元素的添加对快冷Ti合金组织与力学性能的影响

通过铜模铸造法制备出直径为3mm的（Ti66Ni20Cul3A11）100-xSix（x=0,1,3,5）合金圆柱棒。利用X射线衍射仪（XRD）和扫描电子显微镜（SEM）等研究了Si元素的添加对（Ti66Ni20Cul3Al1）100-xSi,（x=0,1,3,5）（原子百分比）合金组织与力学性能的影响。结果表明：当x=0时,形成Ti基非晶复合材料,塑性应变量达4．5％,同时应力达到1774MPa;当x=1时,试样塑性变形量为3．3％,断裂强度达1825MPa。Si的添加使合金析出脆性相,导致试样破坏性脆断。     

添加QCr0.8阻隔层的钛/钢电子束焊接接头组织与性能

采用1.5 mm厚QCr0.8铬青铜作为阻隔层进行了TA15钛合金与304不锈钢的电子束焊接,重点分析了焊接接头的横截面形貌、微观组织和力学性能。结果表明,焊缝中存在约0.5 mm宽的未熔QCr0.8阻隔层,实现了Ti元素与Fe元素的物理隔离,避免了Ti-Fe化合物的形成。铜/钢侧焊缝由铜基固溶体与铁基固溶体组成。而钛/铜侧焊缝中V元素的加入很好地抑制了Ti-Cu界面化合物的大量生成,焊缝组织由铜基固溶体、(Ti,V)基固溶体及少量Ti-Cu化合物组成,提高了该区域的强度和塑性。未熔铜阻隔层在热作用下发生软化,接头拉伸断裂发生在未熔的QCr0.8上,接头抗拉强度为293 MPa,为塑性断裂模式。     

Brazing C/SiC composites and Nb with TiNiNb active filler metal

Abstract

C/SiC composites and Nb were vacuum brazed with the Ti_39·4Ni_39·4Nb_21·2 alloy being the active filler metal. The mechanical properties of the filler material, the microstructure and the strength of brazing joints were investigated. The results showed that the filler TiNiNb alloy has a tensile strength of 860?MPa, an elongation of 51% and an elastic modulus of 78?GPa. Both Ti and Nb elements in the filler reacted with C/SiC during the brazing process, and a well bonded C/SiC–Nb joint was obtained. The ductile filler metal released the thermal stress in the joint. When the brazing was performed at 1220°C for 20?min, the shear strength of brazed joints reached 149, 120 and 73?MPa at 20, 600 and 800°C respectively.     

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 mechanical properties of hot roll bonded joints between titanium alloy and stainless steel using copper interlayer

Abstract

The hot roll bonding was carried out in vacuum condition between titanium alloy and stainless steel using copper interlayer. The stainless steel/Cu can not be bonded if the bonding temperature is lower than or equal to 730°C, and the Cu–Ti alloy can not be bonded if the bonding temperature is higher than or equal to 880°C. The testing results show that the total thickness of intermetallic layers at the interface between copper and titanium alloy increases with the bonding temperature, and the tensile strength of bonded joints decreases with increasing bonding temperature. The maximum strength of 343 MPa was obtained at the bonding temperature of 780°C, the reduction of 20% and the rolling speed of 38 mm s^–1.     

添加铜填充层的Ti-15-3钛合金与304不锈钢电子束焊接过程中的温度与应力场(英文)

采用铜填充金属对Ti-15-3钛合金与304不锈钢进行电子束焊接,对Ti/Fe和Ti/Cu/Fe接头在焊接过程中的温度场和应力场进行数值模拟和试验测量。结果表明,高斯旋转体热源适用于电子束焊接过程的模拟。温度场对于焊缝中心呈非对称分布,钛侧的温度高于不锈钢侧的。热应力同样呈非对称分布,残余拉应力主要存在于不锈钢侧。铜填充金属的加入,降低了焊接过程中的峰值温度、温度梯度以及残余应力,纵向和横向残余拉应力分别降低了66MPa和31MPa。从温度场和应力场的角度可以看出,铜合金是一种较好的Ti-15-3钛合金与304不锈钢电子束焊接的填充金属材料。     

Influence of reinforcement grade and matrix composition on corrosion resistance of cast aluminium matrix composites (A3xx.x/SiCp) in a humid environment

A study of the influence of the silicon carbide (SiC_p) proportion and the matrix concentration of four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) exposed to high relative humid environment was carried out under simulation in a climatic chamber. The matrix of A360/SiC/xxp composites was virtually free of copper while the A380/SiC/xxp matrix contained 3.13‐3.45wt% Cu and 1.39‐1.44wt% Ni. The kinetics of the corrosion process was studied on the basis of gravimetric tests. The nature of corrosion products was analysed by Scanning Electron Microscopy (SEM) and Low Angle X‐Ray Diffraction (XRD) before and after accelerated testing to determine the influence of microstructural changes on corrosion behaviour during exposure to the corrosive environment. The corrosion damage to Al/SiCp composites was low at 80% Relative Humidity (RH) and increased with temperature, SiCp proportion, relative humidity and Cu matrix concentration. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement.     

碳纤维增强Cu-Ti3SiC2自润滑复合材料的研究

介绍了碳纤维的表面处理及碳纤维增强铜基复合材料的制备工艺与性能的研究进展.三元层状碳化物Ti3SiC2兼具金属和陶瓷的优良性能,更有意义的是它具有很好的自润滑性能和比传统的固体润滑剂石墨、二硫化钼更低的摩擦系数.将Ti3SiC2弥散强化Cu与碳纤维复合强化Cu结合,制备出的复合材料,可望有效提高其自润滑性能,被认为在许多领域有着广泛的应用前景.     

CNTs/SiC/Cu复合材料制备及性能

以碳纳米管(CNTs)、碳化硅(SiC)粉体、锌(Zn)粉和CuSO_4·5H_2O为主要原料,用化学镀的方法制备CNTs /Cu复合粉体,再采用非均相沉淀法制备CNTs/SiC/Cu复合粉体.在750 ℃、100 MPa的制度下进行真空热压烧结后制得CNTs/SiC/Cu复合材料,其中Cu的含量(体积分数,下同)为70%,CNTs的含量(体积分数, 下同)分别为0,3%,5%,8%,12%.利用XRD、SEM分析样品的物相组成和显微结构;利用阿基米德排水法、显微硬度计、三点弯曲法测试了复合材料的密度、显微硬度和抗弯强度.结果表明,随着碳纳米管含量的增加,CNTs/SiC/Cu复合材料的密度、显微硬度和抗弯强度等性能发生相应变化,其中,抗弯强度呈现逐渐升高趋势.与未添加碳纳米管的30SiC/70Cu复合材料相比,添加12%CNTs的12CNTs/18SiC/70Cu 样品,抗弯强度提高了21.45 MPa.     

Microstructures and mechanical properties of Al 2519 matrix composites reinforced with Ti-coated SiC particles

Ti-coated SiC_p particles were developed by vacuum evaporation with Ti to improve the interfacial bonding of SiC_p/Al composites. Ti-coated SiC particles and uncoated SiC particles reinforced Al 2519 matrix composites were prepared by hot pressing, hot extrusion and heat treatment. The influence of Ti coating on microstructure and mechanical properties of the composites was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that the densely deposited Ti coating reacts with SiC particles to form TiC and Ti₅Si₃ phases at the interface. Ti-coated SiC particle reinforced composite exhibits uniformity and compactness compared to the composite reinforced with uncoated SiC particles. The microstructure, relative density and mechanical properties of the composite are significantly improved. When the volume fraction is 15%, the hardness, fracture strain and tensile strength of the SiC_p reinforced Al 2519 composite after Ti plating are optimized, which are HB 138.5, 4.02% and 455 MPa, respectively.     

新型铜基块体非晶合金Cu55-xZr37Ti8Inx的制备及性能

利用铜模吸铸法合成Cu—ZrTi—In非晶棒。块体非晶合金Cu50Zr37Ti8In5的△瓦值最大,为66K。从原子尺寸大小和热力学角度分析在铜基非晶合金中添加适量In元素后能够提高其非晶形成能力的原因。在所测的块体非晶合金Cu55．Zr37Ti8Inx（x≤〈5）,Cu52Zr37Ti8In3表现出最高的抗压强度（1981MPa）和最佳的塑性,其在压缩断裂前的总塑性变形量约为1．2％。