激光焊接对块体非晶合金Zr45Cu48Al7 晶化行为的影响

采用激光焊接技术连接块体非晶合金Zr45Cu48Al7(摩尔分数,%).结果表明:在焊接热循环作用下,熔化区和热影响区的晶粒形貌和组织具有很大的差异;焊接速率为2m/min时,熔化区主要生成τ5(Zr38Cu36Al26)、ZrCu和一未知相,热影响区主要生成ZrCu相;焊接速率为4 m/min时,熔化区保持了非晶特性,热影响区部分晶化,其主要生成相为ZrCu相;热影响区的晶化行为与非晶合金热处理过程的晶化行为有一定的区别,其主要原因是激光焊接时的高速加热及冷却过程对各晶化相生长速率影响程度不同.     

激光焊接块体非晶合金Zr45Cu48Al7

采用传统激光焊接技术连接块体非晶合金Zr45Cu48Al7,试验结果显示:焊接速率为2m/min时,熔化区主要生成τ5(Zr8Cu36Al26)相,热影响区主要生成ZrCu相,含有少量τ5相;焊接速率为4m/min时,熔化区保持了非晶特性,热影响区有晶粒生成;当焊接速率8m/min时,热影响区和熔化区均保持非晶特性.     

激光熔覆Zr65Al7.5Ni10Cu17.5复合涂层组织结构

在钛基体上激光熔覆Zr65Al7.5Ni10Cu17.5合金粉末，得到含非晶、纳米晶复合涂层。涂层由金属间化合物和非晶、纳米晶构成。涂层按组织形貌分为3层：表面枝晶区、中部细晶区和结合区枝晶区。金属间化合物为Al2Zr3,Zr2Cu和Zr2Ni，纳米晶为简单四方Al2Zr3相，晶格常数为：a=b=76．18nm，c=69．85nm。     

镁/钢激光-MIG熔钎焊接头微观组织分析及性能研究

在钢表面电镀20μm的纯铜,以AZ31B镁合金焊丝作为填充材料,采用激光-MIG熔钎焊连接AZ31B镁合金和Q235钢,研究不同参数下熔钎焊接头宏观形貌、微观组织及力学性能。结果表明:在合适的焊接参数下,激光-MIG熔钎焊能得到较好的焊缝表面成型。焊接速度为6 mm/s时,钢侧界面区有3～5μm的界面反应层,且为双层结构。通过EDS和XRD分析,钢侧反应层主要是Al Fe3、Al2Cu3化合物,靠反应层的焊缝区是α-Mg固溶体和Mg2Cu、Al CuMg化合物,焊缝中部为是α-Mg固溶体和Al12Mg17化合物。在最优焊接工艺下,抗拉强度最高,达到188.97 MPa。     

摩擦焊焊接块体非晶合金Zr65Cu12.5Al7.5Ni15

采用传统摩擦焊焊接方法连接具有良好非晶形成能力的Zr65Cu12.5Al7.5Ni15(at%)块体非晶合金.微区X射线衍射结果显示,整个焊接接头保持了非晶特性,无晶化反应发生.对摩擦焊焊接方法成功连接块体非晶合金Zr65Cu12.5Al7.5Ni15的原因进行了分析.     

一种新型钛基钎料合金对γ-TiAl合金的钎焊性

在钎焊温度范围为1050 ~ 1125 ℃下保温10 min,采用非晶Ti-Zr-Cu-Ni-Co-Mo钎料成功地实现了Ti-47Al-2Nb-2Cr-0.15B (原子分数,%)合金钎焊连接. 运用SEM,EDS,XRD,TEM和维氏硬度仪等分析研究了铸态和箔带钎料显微组织、温度(900 ~ 1125 ℃)和保温时间(0 ~ 15 min)对铸态钎料在TiAl基合金表面上润湿铺展面积的影响,以及钎焊接头中界面显微组织和维氏硬度在不同钎焊温度下的变化规律. 结果表明,随着温度和保温时间的增加,铸态钎料在TiAl合金母材表面润湿铺展面积的增幅先增大后减小. 钎焊接头界面组织主要包括TiAl母材层,α₂-Ti₃Al+AlCuTi (层Ⅰ)和γ-(Ti, Zr)₂(Ni, Cu)+α-(Ti, Zr)(层Ⅱ). 钎缝中各区域的硬度均随着钎焊温度的增加而增加,1125 ℃时获得最大值为872(±8) HV,主要与钎缝中生成的硬脆金属间化合物(Ti, Zr)₂(Ni, Cu)和α₂-Ti₃Al有关.     

Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15合金的非晶和晶态薄带吸氢行为研究

研究两种不同成分具有较大过冷液相区的四元合金Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15，非晶和晶态薄带吸氢行为，结果表qt两种薄带的吸氢量均随着温度的升高而增大，非晶薄带的吸氢量要小于同等条件下的晶态薄带的吸氢量且只有在673K吸氢后形成了氢化物，Zr65Al7.5Ni10Cu17.5非晶和晶态薄带吸氢后分别生成了Zr2NiH4.7和ZrH2；而Zr65Al10Ni10Cu15非晶和晶态两种薄带最后生成的氢化物同为ZrH2。     

摩擦焊焊接块体非晶体合金Zr65Cu12．5Al7．5Ni15

采用传统摩擦焊焊接方法连接具有良好非晶形成能力的Zr65Cu12．5Al7．5Ni15（at％）块体非晶合金。微区X射线衍射结果显示，整个焊接接头保持了非晶特性，无晶化反应发生。对摩擦焊焊接方法成功连接块体非晶合金Zr65Cu12．5Al7．5Ni15的原因进行了分析。     

铝硅焊丝成分对铜铝异种金属CMT焊接接头特征的影响

采用冷金属过渡(CMT)焊对异种金属T2和1060Al进行焊接,选用S301、ER4043、ER4047 3种焊丝作为填充材料,研究在适当工艺参数下,焊丝成分对焊接接头组织、相组成、界面化合物形态及硬度的影响。结果表明:3种焊丝焊接的接头均由焊缝区、结合区、熔合区组成,且靠Cu侧的焊缝结合区均生成了较厚的界面化合物层。结合区的组织主要为(α-Al+Cu Al2)共晶和Cu Al2金属间化合物相,当采用含Si量12.0%的ER4047焊接时结合区还析出了块状Si。焊丝中添加Si元素,抑制了靠Cu侧焊缝区界面化合物生长,并改变了化合物形态。同时,界面化合物生成,也导致3种焊缝均在靠Cu侧出现显微硬度的高峰区。     

TiAl/Ag-Cu-Ni-Li/35 CrMo感应钎焊接头的组织特征

利用扫描电镜、电子探针及能谱分析等方法,对TiAl／Ag-Cu-Ni-Li／35CrMo感应钎焊的接头组织进行了研究。结果表明,钎焊焊缝沿圆柱试件径向出现宽、窄两反应区：钎焊试件外侧为宽反应区,内侧为窄反应区．两区界线明显。900℃保温5min时的钎焊接头组织结构为：TiAl／TiAl与钎缝间的扩散层／富Ag、Cu相／Ti(Cu,Al)2相／富Ag相／AlM2Ti相(M代表Fe,Cu,Ni)／钎缝与35CrMo间的扩散层／35CrMo。靠近TiAl侧的反应层组织形态依次为等轴细晶和Ti(Cu,A1)2相柱状晶,Ti(Cu,Al)2相柱状晶与TiAl母材存在一定的位向关系。     

SiO2玻璃陶瓷与TC4钛合金的活性钎焊

分别采用活性钎料AgCuTi和TiZrNiCu对SiO2陶瓷和TC4钛合金进行了钎焊连接,使用扫描电镜和X射线衍射等手段对接头的界面组织和力学性能进行了研究.结果表明,采用两种钎料均能够实现对SiO2陶瓷和TC4钛合金的连接;SiO2/TiZrNiCu/TC4接头的典型界面为SiO2/Ti2O+Zr3Si2+Ti5Si3/(Ti,Zr)+Ti2O+TiZrNiCu/Ti基固溶体/TiZr-NiCu+Ti基固溶体+Ti2(Cu,Ni)/TC4;SiO2,AgCuTi/TC4接头的典型界面为SiO2/TiSi2+Ti4O7/TiCu+Cu2Ti4 O/Ag基固溶体+Cu基固溶体/TiCu/Ti2Cu/Ti+Ti2 Cu/TC4.当钎焊温度为880℃和保温时间为5 min时,SiO2/TiZrNiCu/TC4接头的最高抗剪强度为23 MPa;当钎焊温度为900℃和保温时间为5 min时,SiO2/AgCuTi/TC4接头的最高抗剪强度为27MPa.     

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.     

合金元素对Ti-Ni-Cu系钎料性能的影响

本实验设计一系列不同成分的Ti-Ni-Cu系钎料,研究合金元素B、Si、Zr等对钎料非晶形成能力和性能的影响.结果表明:微量B、Si元素均能显著改善Ti-Ni-Cu系钎料对Si3N4陶瓷的润湿性;在相同试验条件下,添加0.2%B的Ti40Ni15Cu钎料铺展面积最大;不含zr元素的Ti-Ni-Cu系钎料合金的非晶形成能力均很差.本实验设计的Ti40Zr20Ni20CuB0.2、Ti40Zr20Ni25CuB0.2两种钎料既具有良好的润湿性,又具有良好的非晶形成能力;与Ti40Zr25Ni15Cu非晶钎料钎焊Si3N4陶瓷的接头相比,Ti40Zr20Ni20CuB0.2、Ti40Zr20Ni25CuB0.2非晶钎料钎焊Si3N4陶瓷接头的室温强度变化不大,但高温强度有明显提高.     

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.     

Behaviors of interfacial elements during the brazing of SiO2 glass ceramic to Ti-6Al-4V with AgCu/Ni interlayer

AgCu/Ni composite interlayer was used to join SiO₂ glass ceramic to Ti-6Al-4V alloy successfully, obtaining the largest joint shear strength 110MPa. Ag, Cu and Ni in the interlayer and Ti in the Ti-6Al-4V alloy affect the joint formation and interfacial products significantly. To understand the joint formation process better, behaviors of elements Ag, Cu, Ni and Ti during the brazing of SiO₂ glass ceramic to Ti-6Al-4V alloy were investigated in the present work. Active element Ti is the most important component in the joining, realizing the metallurgical bonding of SiO₂ glass ceramic to braze alloy. Cu together with Ni reacts to Ti in the base material by Ti-Cu-Ni ternary eutectic reaction, which is beneficial for reducing the massive Ti-Cu and/or Ti-Ni brittle intermetallic compounds on the joint interface. Dispersion of Ag decreases the brittleness of the whole joint effectively.     

TiAl基合金与Ti合金的真空钎焊

采用Ag-Cu钎料与Ti-Zr-Ni-Cu钎料,对TiAl与Ti合金进行了真空钎焊试验,主要研究了采用两种钎料时的界面反应以及钎焊温度对界面组织及性能的影响.研究发现,采用Ag-Cu钎料时界面结构为:Ti/Ti(Cu,Al)2/TiCux Ag(s,s)/Ag(s,s)/Ti(Cu,Al)2/TiAl,当钎焊温度T=1 223 K,保温时间t=10 min时接头的剪切强度达到223.3 MPa;采用Ti-Zr-Ni-Cu钎料时在界面出现了Ti2Ni,Ti(Cu,Al)2等多种金属间化合物,当钎焊温度T=1 123 K,保温时间t=10 min时接头的剪切强度达到139.97 MPa.     

Microstructure evolution of the Si3N4/Si3N4 joints brazed using Au-Ni-V filler alloys with different V content

Au-Ni-V filler alloys with different vanadium contents were designed to braze Si₃N₄ ceramic at 1373 K for 30 min, and the microstructures of brazing seams were investigated by SEM and TEM. When the Au-Ni-V filler alloy contains 5 at.% V, round-like Ni[Si, V, Au] precipitates form in the Au[Ni] solid solution matrix and a VN reaction layer with 0.5 μm thickness appears on Si₃N₄ interface. When the V content increases to 10 at.%, a new polygonal Ni₂SiV₃ phase occurs in the seam, and the Ni[Si, V, Au] precipitate coarsens and VN layer thickens. With increase of V contents to 15 and 20 at.%, laminar Ni[Au] and polygonal Ni₃V precipitates form. With 25 at.% V content in the filler alloy, the Ni₂SiV₃ and Ni₃V precipitates distribute homogenously in the brazing seam. These microstructure evolutions were attributed to the reaction between Si₃N₄ and vanadium, which forms VN reaction layer and releases Si into the molten alloy.     

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.     

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。