钛合金与不锈钢超塑性扩散连接工艺及机理研究

基于微细晶超塑性扩散连接方法,对TC4钛合金与1Cr18Ni9Ti不锈钢成功实现了直接扩散连接,系统分析了接头性能、界面微观结构及超塑性扩散连接机理。结果发现：TC4钛合金与1Cr18Ni9Ti奥氏体不锈钢直接超塑性扩散连接时,较佳连接工艺规范为：温度T=760~820 ℃,压力p=6~9 MPa,时间t=20~40 min;接头剪切强度τ＝125.3~148.7 MPa。与一般直接扩散连接相比,连接温度降低了约100 ℃,接头的剪切强度提高了1倍以上,且连接试样无明显变形。细化热处理TC4钛合金与1Cr18Ni9Ti不锈钢超塑性扩散连接时,其接头的形成过程大致可分为3个阶段：形成紧密接触阶段、接触表面激活阶段及靠近活化中心的界面冶金结合区形成阶段。     

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.     

表面纳米化钛合金与不锈钢扩散连接

采用高能喷丸(HESP)对TA17钛合金和0Cr18Ni9Ti不锈钢棒材的连接面进行了表面自纳米化(SSNC)处理,在连接面获得了一定厚度的纳米晶组织层。将钛合金和不锈钢的纳米化处理连接面对接,在热模拟试验机上进行恒温恒压和脉冲加压扩散连接。测试接头拉伸强度,并对断口和接头显微组织进行分析。结果表明,采用脉冲加压扩散连接,接头界面处生成的金属间化合物层较薄,接头抗拉强度高达384.0MPa;断口呈脆性断裂特征。     

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.     

TiC-TiB2陶瓷与Ti6Al4V熔化连接及层状复合材料制备

通过引入Ti-6Al-4V合金板,采用超重力场燃烧合成技术,在制备细晶TiC-TiB2凝固陶瓷的同时,实现了陶瓷-钛合金的熔化扩散焊,进而制备出具有成分梯度特征的陶瓷-钛合金层状复合材料.陶瓷-钛合金层间接头组织表明,正是因超重力场燃烧合成的爆燃特性及超重力场对燃烧产物形成的高温真空环境,使得钛合金表面发生熔化,进而发生液态陶瓷-钛合金液相层间的原子互扩散现象,故在陶瓷-钛合金连接区形成钛合金与富钛碳化物呈相间分布且细小TiB2片晶镶嵌其上的凝固组织,并使陶瓷-钛合金接头呈现成分梯度特征,进而使得陶瓷-钛合金的连接抗剪强度达到450 MPa±35 MPa,层状复合材料硬度从陶瓷至钛合金一侧则呈线性逐渐减小.     

中间过渡金属对钛合金与不锈钢扩散焊接头强度的影响

采用加中间过渡金属的工艺方法，对钛合金ＴＣ４与不锈钢１Ｃｒ１８Ｎｉ９Ｔｉ扩散焊接头的结合强度进行了试验研究，利用扫描电镜，电子探针仪等对接头进行了微观分析。结果表明，采用纯镍作中间过过渡金属虽然有效地防止了钛与铁，碳间的相互扩散和迁移，但在镍与钛之间却形成了金属间化合物薄层，致使接头的最高强度在３８０ＭＰａ左右；采用钒＋铜复合过渡金属彻底地消除了钛合金－不锈钢接头中的金属间化合物和碳化物。     

Diffusion bonding/superplastic forming of Ti-6Al-6V-2Sn/SUS 304 stainless steel/Ti-6Al-6V-2Sn

The superplasticity of the Ti- 6Al- 6V- 2Sn alloy for different temperatures was evaluated by single-sheet free blowing. The optimal superplastic temperature for the Ti- 6Al- 6V- 2Sn alloy was found to be 850 °C. Diffusion bonding of Ti- 6Al- 6V- 2Sn and 304 stainless steel was carried out in a vacuum. The interface of both bonded alloys was examined by EPMA. The concentration profile of Ni exhibited a peak at the interlayer and a valley adjacent it, whereas that of Cr exhibited a peak where Ni showed the valley. X- ray diffraction (XRD) analyses showed that the Fe ₂ Ti, NiTi, and CrMn Intermetallic compounds and the Cr element formed at the interface. The thickness profiles of the blown specimens were measured and compared with theoretical calculations.     

表面纳米化钛合金与不锈钢脉冲加压扩散连接

采用高能喷丸（HESP）对TA17钛合金和0Cr18Ni9Ti不锈钢棒材的端面进行了表面自纳米化（SSNC）处理,在端面获得了一定厚度的纳米晶组织层。将钛合金和不锈钢的纳米化处理端面对接,在Gleeble-1500D热模拟试验机上进行脉冲加压扩散连接。对接头进行了拉伸试验,并对断口和接头显微组织进行了研究分析。结果表明,接头强度高达384．0MPa,与在相同条件下获得的常规粗晶的接头强度相比,有显著的提高。接头在拉伸时发生脆性断裂,接头剖面的显微硬度随显微组织而变化。     

超声波焊接制备功能梯度材料

采用超声波焊接的方法成功制备了功能梯度材料,它具有简便、环保、快速成型的特点.实验以铝合金6061、3003、纯钛、钛合金Ti-6Al-4V和纯镍为材料,利用超声波焊接方法制备Al/Ti/Ni功能梯度材料.通过金相显微分析、显微硬度分析、EDS分析对其焊接界面的微观结构、显微硬度、焊缝原子扩散程度进行测试和表征.结果表...     

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.     

Transient liquid phase diffusion bonding of copper alloy to stainless steel using CuMn alloys as interlayer

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Diffusion bonding of copper alloy to stainless steel with Ni and Cu interlayer

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Ti3Al基合金的弹性变形能与空蚀

利用旋转圆盘装置研究了Ti3Al基合金Ti-24A1-15Nb-1Mo的空蚀行为，并用洛氏硬度仪模拟空蚀过程中微射流所产生的局部载荷对Ti-24A1-15Nb-1Mo合金的作用，测量了压头加载过程中该合金吸收的总能量和弹性变形能(选择我国水利机械常用0Cr13Ni5Mo马氏体不锈钢作对比材料)。结果表明：Ti-24Al-15Nb-1Mo合金的抗空蚀性能优于0Cr13Ni5Mo不锈钢，空蚀40h后前者的累积体积损失量仅为0．551mm^3，而后者的累积体积损失量达到2．615mm^3；在局部载荷作用下，Ti-24Al-15Nb-1Mo合金不仅有较高的加工硬化能力，而且有较好的弹性性能；在压痕试验中其弹性变形能在总变形能量中所占比例达到1／3。这些性能特点使Ti-24Al-15Nb-1Mo合金在空蚀过程中能吸收和释放较多的冲击能量，延缓裂纹形成，减少体积损失，呈现良好的抗空蚀性能。     

机械合金化制备纳米晶Ti-6Al-4V合金

采用机械合金化制备Ti-6Al-4V粉末。结果表明:采用机械合金化可以制备纳米晶Ti-6Al-4V合金粉,其反应机理以扩散为主,该固态反应是缺陷能和碰撞能共同作用的结果;随球磨时间延长,部分V固溶于Ti中形成置换固溶体Ti(V),球磨过程中没有中间相生成。球磨40 h后都能获得纳米晶,60 h的粉末为纳米晶和非晶的混合物,晶粒尺寸小于60 nm;60 h后晶粒尺寸变化缓慢。球磨后Ti、Al、V的原子比近似为90:6:4,与Ti-6Al-4V元素成分一致。     

Cavitation erosion resistance and ratio of elastic deformation energy to total deformation energy for Ti_3Al and TiNiNb alloys

1　INTRODUCTIONCavitationerosioniscausedbythegrowthandcollapseofvaporcavitiesorbubblesduetolocalpres surefluctuationinaliquid[1] .Itisaseriousprobleminhigh speedcomponentsofhydraulicmachines .Al thoughagreatamountofworkonthecavitationphe nomenahasbeen published ,thecavitationerosionmechanismofmaterialsisstillnotunderstoodcom pletely .Itisgenerallybelieved[2 ,3] thatmechanicalattackisadominantmechanismforcavitationero sion .Manyinvestigations[4 6 ] attemptedtocorrelatethemechanicalproperti…     

钛合金板与不锈钢丝网异质接头焊接

采用不同的滚焊和真空扩散焊工艺研究了TC4钛合金板与00Cr18Ni13不锈钢丝网的异质接头的焊接问题.焊缝显微分析显示,无论是滚焊或真空扩散焊,无论焊接参数大小,都无法避免异质接头直接扩散焊时产生内应力和脆性的金属间化合物相,并形成裂纹.滚焊和较小的焊接参数只能减少焊接缺陷的产生,较大的焊接参数的扩散焊直接导致未熔合和开裂.采用中间过渡层并产生微观机械咬合的焊接接头性能较好.     

采用氢化-脱氢（HDH）钛粉和氢化钛粉制备MIMTi-6Al-4V合金

以HDH钛粉制备MIM Ti-6Al-4V合金的过程为参照,对使用氢化钛粉为原料制备P/M模压钛合金以及MIM钛合金的工艺过程进行了探索.使用HDH钛粉制备的MIM Ti-6Al-4V合金抗拉强度为819 MPa,拉伸样延伸率为7%;使用氢化钛粉制备的P/M模压Ti-6Al-4V合金拉伸样抗拉性能高于850 MPa;使用氢化钛粉为原料制备MIM Ti-6Al-4V合金,顺利实现了脱氢-脱脂过程.     

Ti_2AlNb相合金Ti-22Al-25Nb的TLP扩散连接

以Ti-15Cu-15Ni合金薄带作中间层,用Gleeble 1500D热-力学模拟试验机对Ti2AlNb相合金Ti-22Al-25Nb进行TLP扩散连接。研究了连接参数对接头组织演变、元素分布、接头强度及其断裂特征的影响。结果表明,接头形成过程由5个阶段组成,Nb是接头成分均匀化的扩散主控元素。适当延长保温时间和适当提高连接温度有利于获得组织与成分均匀的高强接头。保温结束后接头快速冷却时,其连接区室温组织为B2相;而采用慢冷工艺有利于促进高温β相的相变从而改善连接区组织,室温组织为B2相基体和少量α2、O相。连接温度和保温时间分别为990℃和90min且采用慢冷工艺时,接头的室温和650℃抗拉伸强度分别为1041MPa和659MPa,分别达到原始母材强度的95％和81％,明显高于采用快冷工艺的接头强度。     

新型含钯镍基钎料钎焊不锈钢接头的性能分析

对新型Ni-Pd-Ag-Cr-Si钎料钎焊1Cr18Ni9Ti不锈钢的接头性能进行了分析。结果表明,新型Ni-Pd-Ag-Cr-Si钎料对1Cr18Ni9Ti不锈钢有良好的润湿性;钎焊接头中,紧靠钎缝与母材界面的是与该界面平行的长条形齿状镍钯基固溶体致密组织。这种固溶体具有较高的强度和塑性,钎缝宽度为170μm时,钎缝仍具有较高的剪切强度,利于保证钎焊不锈钢产品质量不发生重大变化。     

模拟酸雨组分对1Cr18Ni9Ti不锈钢土壤腐蚀行为的影响

利用极化曲线和电化学阻抗谱(EIS)等方法研究了模拟酸雨组分对1Cr18Ni9Ti不锈钢在土壤中腐蚀行为的影响。结果表明,酸雨组分对1Cr18Ni9Ti不锈钢腐蚀行为影响显著。随着SO42-与NO3-浓度比的减小,不锈钢的腐蚀速率减小,说明硫酸型酸雨对本体系的腐蚀性明显强于硝酸型酸雨。不锈钢的电化学阻抗谱表现为双容抗弧,其腐蚀过程主要受氧扩散过程控制。