铜中间层钛-钢扩散复合界面组织与性能

利用真空扩散焊方法制备了铜中间层钛-钢焊接接头,并采用OM、SEM、EDS、显微硬度和拉伸试验方法,研究了铜中间层钛-钢扩散复合界面组织和性能。结果表明,Fe、Ti原子在界面处发生了互扩散,钛侧形成α-βTi+αTi或βTi+α-βTi+αTi组织,钢侧发生脱碳并形成柱状晶组织;拉伸强度随扩散温度升高呈现先增加后减小的趋势,950℃、30 min扩散试样拉伸强度最高,达到262 MPa;拉伸断口具有塑性断裂区与脆性断裂区特征,并在断口上检测出TiC相。     

钒中间层钛/钢复合板结合界面结构与力学性能

利用真空热轧复合方法制备了钒中间层钛/钢复合板,采用SEM、EDS和XRD等分析结合界面形貌、元素扩散行为和界面相组成。结果表明:钒中间层钛/钢复合板界面实现了良好的冶金结合。与拉剪强度测试相结合,研究了钒中间层钛/钢复合板结合界面结构与力学性能。结果表明:钒中间层钛/钢复合板剪切强度均优于国家标准(140 MPa)。950℃轧制的复合板界面扩散层厚度大于900℃轧制的复合板扩散层厚度。钒中间层与Ti、Fe元素形成固溶体,有效阻止了金属间化合物TiFe和TiFe_2的产生。900℃轧制的钛钢复合板剪切强度为223 MPa,大于950℃轧制的复合板剪切强度。对剪切断口的分析表明裂纹多沿钒铁固溶体产生并扩展。     

钛-钢扩散复合界面组织与结合强度

将钛管、钢管利用冷拔-内压扩散法制备了内包覆钛-钢复管.用扫描电镜、能谱分析、X-光衍射和拉剪试验等方法,研究了扩散退火温度与时间对钛-钢扩散复合界面附近组织、成分和界面剪切强度的影响.结果表明,该制备方法可使钛-钢实现冶金结合;界面剪切强度随扩散温度升高先增加后减小;750-800℃×0.5h扩散退火界面剪切强度最高,可达210MPa左右;扩散退火中Fe、Ti原子发生了互扩散;界面上有TiC形成;750℃×0.5 h扩散退火试样断口未检测到TiFe、TiFe2相;900-950℃×0.5h扩散退火钢侧出现柱状晶区,钛侧出现无晶界晶区与针状马氏体晶区.     

TiNi形状记忆合金与不锈钢的瞬时液相扩散焊

采用AgCu金属箔作中间过渡层,对TiNi形状记忆合金与不锈钢进行了瞬时液相扩散焊,分析了接头的显微组织、元素分布和物相组成等,研究了接头的抗剪强度和断裂方式。结果表明:接头界面区由TiNi侧过渡区,中间区,不锈钢侧过渡区组成,主要相分别为Ti(Cu,Ni,Fe),AgCu,TiFe等。连接温度为860℃,保温时间为60min,连接压力为0.05MPa时,接头最大抗剪强度为239MPa。断裂发生在TiNi母材和AgCu中间层扩散界面上,断口为混合断裂形貌。通过中间层等温凝固过程动力学模型,结合界面形貌和元素扩散分析,认为TiNiSMA与不锈钢异种材料瞬时液相扩散焊过程存在明显的非对称性。     

Ti_3Al/Ti/Ti_2AlNb扩散连接工艺及性能

采用钛箔作为中间层扩散连接Ti3Al与Ti2AlNb,利用SEM,EDS和XRD等分析方法发现,接头界面组织结构为Ti3Al/α+β双相组织/富B2相/Ti2Al Nb.分别研究了中间层厚度,连接温度,保温时间等工艺参数对接头界面组织形貌以及力学性能的影响.结果表明,当钛箔厚度10μm,T=900℃,t=120 min,p=5 MPa时,接头组织性能最佳.钛箔厚度增加会导致Ti,Al,Nb等元素扩散不均匀;Ti3Al/Ti2Al Nb直接固相扩散连接温度为1 000℃,加入钛中间层可将其降低至900℃,减小了高温热循环对母材性能的损伤,接头整体抗拉强度从795 MPa提升至906MPa;保温时间90~120 min可保证扩散充分连接可靠.     

钛-钢扩散复合界面组织与结合强度

将钛管、钢管利用冷拔-内压扩散法制备了内包覆钛-钢复管。用扫描电镜、能谱分析、X-光衍射和拉剪试验等方法，研究了扩散退火温度与时间对钛-钢扩散复合界面附近组织、成分和界面剪切强度的影响。结果表明，该制备方法可使钛～钢实现冶金结合；界面剪切强度随扩散温度升高先增加后减小；750—800℃×0．5h扩散退火界面剪切强度最高，可达210MPa左右；扩散退火中Fe、Ti原子发生了互扩散；界面上有TiC形成；750℃×0．5h扩散退火试样断VI未检测到TiFe、TiFe2相；900—950℃×0．5h扩散退火钢侧出现柱状晶区，钛侧出现无晶界晶区与针状马氏体晶区。     

用复合中间层扩散连接钛铝基合金与镍基合金

采用Ti／Nb和Ti／Nb／Ni复合中间层扩散连接钛铝基合金与镍基合金．采用扫描电镜、电子探针等手段对接头的界面组织及断口进行分析,采用抗剪强度测试对接头的连接强度进行评价．结果表明,在连接温度为900℃,连接压力为20MPa固定的情况下,采用Ti／Nb复合中间层,在连接时间为30min时,接头抗剪强度最高为273．8MPa,接头断裂于GH99／Nb界面;采用Ni／Nb／Ti复合中间层,在连接时间为60min时,接头抗剪强度最高为314．4MPa,接头断裂于Ti／TiAl界面的Ti3Al反应层．采用Ni／Nb／Ti复合中间层所得接头强度较Nb／Ti复合中间层有较大提高,且接头的断裂位置发生变化,说明镍中间层的加入,对缓解接头应力有一定的作用．     

轧制加热温度对钛/钢复合板组织与性能的影响

采用钢/钛/隔离剂/钛/钢对称结构复合板坯,研究了轧制加热温度(850-1000℃)对钛/钢复合板显微组织、基材强韧性和界面结合性能的影响。结果表明,随着轧制加热温度的升高,界面剪切性能逐步下降。加热温度影响着界面反应相的种类和厚度。在850,875,900℃条件下,轧后冷却扩散过程中,C极容易在钛/钢界面形成TiC层,阻碍了Fe向Ti中扩散,因而界面形成TiC和β-Ti反应层;在950℃和1000℃条件下,由于C在β-Ti中的扩散系数为C在γ-Fe扩散系数的10倍以上,C不能在结合界面富集形成有效的TiC屏障,此时Fe能够在Ti中充分扩散,从而形成了Fe-Ti金属间化物层、TiC层、β-Ti层和α-β Ti层。脆性反应相的厚度与加热温度呈正相关关系。脆性相种类和厚度增加使得钛/钢复合板界面剪切强度出现下降。     

保温时间对316L不锈钢与TC4钛合金扩散焊组织与性能的影响

利用真空扩散焊接方法,研究了不同保温时间对不锈钢和钛合金焊接接头组织与性能的影响。结果表明,不锈钢与钛合金在900℃下直接进行扩散焊接,难以得到较好的性能。随保温时间延长接头强度逐渐降低,在保温120 min时得到最高屈服强度为43.01 MPa。焊缝界面处主要形成α-Ti、β-Ti、FeTi、Fe_2Ti、Cr_2Ti、Fe_2Ti_4O、χ等金属间化合物相,由钛合金侧到不锈钢侧依次为针状魏氏体区域、β-Ti区、脆性化合物区。随着保温时间延长,脆性相含量逐渐增多。断裂发生在脆性化合物区,断口呈现河流花样,为脆性断裂。     

Q345/Al_2O_3陶瓷扩散接头的组织与性能

采用铜粉(75wt%)+钛粉(25wt%)做中间层对Q345钢与Al_2O_3陶瓷进行了扩散连接,用扫描电镜、能谱仪和X射线衍射仪对接头界面和剪切断口进行了微观表征,并用电子万能试验机测试了接头的剪切强度。结果表明:Q345/Al_2O_3接头界面成形良好,连接可靠;在加热温度1000℃、保温时间30 min、压力45 k Pa参数下,接头存在明显的Q345侧反应层、Cu-Ti中间层、Al_2O_3侧反应层,物相主要为Ti Al3、Ti O_2、Cu_2Ti_4O、Ti_2Cu_3、Cu O、Ti Fe_2、Ti Mn5和Fe基固溶体。剪切试验显示,随着温度的增加剪切强度先增加后降低,加热温度为1000℃时,剪切强度达到最大(70.6 MPa),剪切断口形貌为脆性断裂,断裂位置主要发生在近陶瓷侧。     

Impact pressuring diffusion bonding of TA17 to 0Cr18Ni9Ti

Impact pressuring diffusion bonding tests were carried out to produce joint between TA17 titanium alloy and 0Cr18Ni9Ti stainless steel. The reaction products and microstructure near the bonding interface were analyzed. The diffusion of Fe, Cr, Ni and Ti in the bond was revealed by energy dispersive spectroscopy. A number of phases, such as β-Ti, Fe2Ti and σ phases were identified by X-ray diffraction. It was concluded that the bonded joint broke in the region somewhere between Fe-Ti intermetallics and β-Ti during tensile loading. The relationship between bonding parameters and tensile strength of the joint was also determined experimentally, and the optimum time of bonding was only 220 s with 293 MPa joint strength.     

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.     

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...     

钛合金与不锈钢真空热轧连接界面微观结构及性能

完成了TC4钛合金与304不锈钢的直接真空热轧连接,连接界面微观结构的研究结果表明,当压缩率20%,轧制速度0.038 m/s时,轧制温度800℃时连接界面存在未连接的孔洞,轧制温度850℃时连接界面形成了三层金属间化合物层,其中富铬层硬度约为母材钛合金硬度的2倍,轧制温度900℃时连接界面产生了金属间化合物层之间或金属间化合物层与母材之间的开裂现象.轧制温度850℃时接头抗拉强度最高,可达77.33 MPa.拉伸试样均为脆性断裂,不锈钢一侧的断口存在γFe,Cr,Fe₂Ti,σ和Cr₂Ti.     

Solid state diffusion bonding of titanium to steel using a copper base alloy as interlayer

Dissimilar titanium/steel metals were successfully joined by diffusion bonding process with the help of a copper-based interlayer. The appropriate processing parameters have been investigated and the joints were analyzed by means of scanning electron microscopy (SEM), microhardness measurement, shear strength test, and X-ray diffractometry (XRD). The results show that the joint could not be bonded at a temperature lower than 800 °C even at holding time of 180 min. However, at 850 °C successful joining was achieved at all holding times. On the other hand, atom diffusion and migration between Ti and Fe or C were effectively prevented by adding a copper-based interlayer and hence, Fe–Ti and Ti–C intermetallics were not formed in the joint. This technique provides a reliable method of bonding titanium to steel.     

Study of diffusion bonding of Ti-6Al-4V and ZQSn10-10 with metal interlayer

The diffusion bonding was carried out to join Ti alloy (Ti-6Al-4V) and tin-bronze (ZQSn10-10) with Ni and Ni Cu interlayer. The microstructures of the diffusion bonded joints were analyzed by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that when the interlayer is Ni or Ni Cu transition metals both could effectively prevent the diffusion between Ti and Cu and avoid the formation of the Cu-Ti intermetallic compounds (Cu3Ti, CuTi etc.). But the Ni-Ti intermetallic compounds (NiTi, Ni3Ti) are formed on the Ti-6Al-4V/Ni interface. When the interlayer is Ni, the optimum bonding parameters are 830℃/10 MPa/30min. And when the interlayer is Ni Cu, the optimum bonding parameters are 850℃/10MPa/20min. With the optimum bonding parameters, the tensile strength of the joints with Ni and Ni Cu interlayer both are 155.8MPa, which is 65 percent of the strength of ZQSn10-10 base metal.     

Microstructure and mechanical properties of diffusion bonded titanium/304 stainless steel joint with pure Ag interlayer

Abstract

In the present study, diffusion bonding of commercially pure titanium to 304 stainless steel (SS) using a pure Ag interlayer was carried out. It is found that the pure Ag interlayer can effectively block the interdiffusion and interaction between Ti and SS. The resultant joints were composed of Ti substrate, Ti–Ag solid solution, TiAg intermetallic phase, the remnant Ag interlayer and SS. Upon tensile loading, fracture took place through the remnant Ag interlayer, indicating that the TiAg intermetallic phase exhibits no detrimental effect on the strength of the joints. A maximum tensile strength of 421 MPa was achieved, which is notably improved compared with previous results. Furthermore, extensive dimples were observed on the fracture surfaces, clearly indicating that the joints were ductile in nature.     

退火对TA1/5052爆炸复合板界面组织与性能的影响

将TA1/5052爆炸焊接复合板在350、400及450 ℃分别保温1、3、6、9 h退火,对退火前后复合板组织和性能进行分析。结果表明:随退火温度升高,原子扩散加剧,界面形成的扩散层逐渐变厚;退火过程中铝易于向钛侧扩散,白色亮带和柯肯达尔孔洞主要位于靠近界面的5052铝合金侧;退火前界面处物相组成为α-Ti、α-Al、TiAl₃,经350、400 ℃退火3 h及450 ℃退火1、3、6、9 h后,物相组成不变。经不同温度退火后,复合板界面抗拉强度低于退火前,而断面收缩率和伸长率明显高于退火前。拉伸断口分析表明,复合板TA1侧为以脆性断裂为主、韧性断裂为辅的韧脆混合断裂,5052侧为韧性断裂;复合板在350 ℃退火时界面剪切强度和剥离强度最大,较爆炸态分别增加8.24%和45.68%,随退火温度升高,界面剪切强度和剥离强度降低。退火前后界面结合区硬度均高于基复板两侧硬度,且随离界面距离增加,硬度逐渐降低直至降至钛铝两侧母材硬度。退火后界面结合区硬度明显低于爆炸态硬度。     

Diffusion bonding of Ti-6Al-4V to ZQSn10-10 in vacuum

The experimental investigation of the direct diffusion bonding of Ti-6Al-4V to ZQSn10-10 was carried out in vacuum. The microstructure of bonded joint was studied by scanning electron microscopy （SEM）, energy dispersive spectroscopy （ EDS ） and the mechanical properties were detected by the tensile experiments. The microstructure and tensile strength of the joint mainly depend on the bonding temperature and bonding time. A satisfying diffusion bonded interface with a tensile strength of 73.9 MPa can be obtained under the condition of bonding temperature 850℃ for 30 rain. Three kinds of reaction products were observed in the bonded interface, namely β-Ti, CoaTi and CuSn3Ti5. And the brittle Cu3Ti and CuSn3 Ti5 are mainly responsible for lowering the strength of the bonded joint. The diffusion distances of Sn , Cu and Ti and square root of bonding time are approximately linear relationship. And diffusion velocity of Sn, Cu and Ti in the diffusion reaction layer are 0. 013 9,0. 069 7 and 0. 056 4 mm^2/s.