钛—镍—不锈钢接头中元素的扩散及其对性能的影响

采用纯镍作中间过渡金属，对镀合金ＴＣ４与不锈钢１Ｃｒ１８Ｎｉ９Ｔｉ扩散焊接头的结合性能进行了试验研究，利用电子探针测定了扩散层中元素的分布，结果表明，采用镍作中间过渡金属，可以获得钛合金与不锈钢的牢固连接，但在镍与钛之间还是形成了金属间化合物薄层，对接头的性能有较大的影响。     

不锈钢和钛合金异种金属焊接研究进展

不锈钢和钛合金异种焊接在化工、航空和核工业等领域均有广泛的应用,但不锈钢和钛合金因理化性能的差异,焊接界面常形成大量脆性金属间化合物,无法得到优质的焊接结果。以扩散焊、激光焊和电子束焊为主总结了不同焊接方法的工艺参数和接头组织成分对不锈钢和钛合金焊接质量的影响,展望了不锈钢与钛合金异种金属焊接的发展趋势。     

钛合金作动部件耐磨性能提升及工程化应用研究

为提升钛合金表面硬度，增强其耐磨性能以满足新一代航空作动系统部件对减重及耐高温的需求，开展钛合金化学镀镍及不锈钢CMT(冷金属过渡焊接技术)熔覆SCu6180(铝青铜)工艺研究，并对其不同强化状态摩擦副的耐磨性能进行了模拟工况条件下的环-块摩擦磨损试验。结果表明：钛合金前处理采用低压吹细砂+氢氟酸活化，化学镀镍层结合力良好，真空炉399℃热处理，硬度可达906 HV_{1 N},与不锈钢摩擦副的摩擦系数由0.79下降到0.32;与表面熔覆SCu6180减摩涂层不锈钢摩擦副的摩擦系数仅为0.12,磨损量下降2个数量级并实现发动机矢量作动部件的工程化应用。     

超弹性镍钛合金电镀前处理研究

研究了超弹性镍钛合金的电化学性质，镍钛合金表面存在的纯化膜而导致的镀层与基体结合力不良的问题，采用具有溶解和活化作用的浸蚀液以及合适的预镀层，并且选用具有整平能力的镀怪作用为中间镀层，从而得到结合力良好、外观平滑光亮的镀金层，解决了镍钛合金产品的装饰性问题。     

高温钛合金中杂质元素Fe的扩散行为及其对蠕变抗力的损害作用

高温钛合金是先进航空发动机压气机应用的理想材料,代替钢或镍基高温合金,可以显著提高发动机的推重比和服役性能.随着钛合金使用温度的提高,高温蠕变抗力越来越成为影响其使用温度和使用寿命最关键的力学性能.在400～600℃的温度范围内,钛合金的蠕变变形一般受位错攀移机制所控制,蠕变激活能近似等于有效扩散激活能,因此,扩散是影响钛合金高温蠕变抗力的最主要因素.杂质元素Fe在钛合金中具有反常大的扩散能力,是Ti自扩散系数的103～105倍,在Ti中的扩散可能受离解扩散机制所控制.钛合金中的微量Fe同时会显著促进Ti的自扩散,提高位错攀移速率,从而降低蠕变抗力.为了改善高温钛合金的蠕变性能,需要严格控制原材料如海绵钛和中间合金中杂质Fe的含量.     

TiNi形状记忆合金与不锈钢瞬间液相扩散焊工艺研究

采用AgCu中间.过渡层,研究了连接温度、保温时间和连接压力对TiNi形状记忆合金与不锈钢瞬间液相扩散焊接头剪切强度的影响规律.本实验条件下连接温度为860℃,保温时间为60min,连接压力为0.05MPa时接头剪切强度最大为239.4MPa.通过扫描电镜(SEM)和X射线衍射仪(XRD)研究了最佳工艺参数下接头的元素分布和相组成,结果表明:接头生成了TiNi2,TiFe和Ti3Ni4等金属间化合物,从而影响接头性能.     

超弹性镍钛合金血管内支架的有限元分析

镍钛合金由于其优良的机械性能和生物相容性已经被广泛的应用于生物医用领域,然而由于其超弹性为高度非线性的应力 应变关系,如何对其相关器械的性能进行分析与评价是设计人员面临的主要问题。本文介绍了有限元技术中镍钛合金材料模型的建立方法,并利用有限元软件 ANSYS8.0 分析了一种超弹性镍钛合金血管内支架的自膨胀过程。结论为支架释放后,将对支架端部血管产生较高的内应力,这容易损伤此处血管,引起血栓及内膜增生等问题;镍钛合金支架释放后,对应的应力水平只有 300MPa左右,远远小于不锈钢支架的应力值。因此,支架的柔顺性更好,对血管的刺激更小,这对于提高支架的植入效果将有很大的帮助;有限元技术可以方便的对镍钛合金器械进行模拟分析,这对于镍钛合金器械的研制与开发将有很大的帮助。     

DD3单晶合金对开叶片TLP扩散焊工艺探索研究

以我国第一代镍基单晶高温合金DD3为研究对象，采用为DD3合金配制的非晶态箔状中间层合金D1F，对DD3合金瞬间过渡液相扩散焊(TLP扩散焊)接头组织与性能进行了分析，接头高温持久性能达母材性能指标的90％。同时对DD3单晶合金对开叶片扩散焊可行性进行了探索。     

不锈钢与钛合金纳秒激光焊接工艺研究

目的 针对不锈钢与钛合金异种金属焊接时,容易产生间化合物,导致焊点拉力低的现象,通过纳秒激光焊接工艺来提高不锈钢与钛合金异种金属焊接的焊点拉力.方法 采用纳秒光纤激光器进行304不锈钢与TC4钛合金的焊接实验,通过激光运行螺旋线组成焊点,并对工艺参数进行正交试验,得到焊点拉力最大的工艺参数.结果 当激光功率为90 W,...     

一种新型医用高氮无镍不锈钢的生物相容性研究

研究了成骨细胞及血小板在不同氮含量的新型高氮无镍奥氏体不锈钢材料表面的粘附及细胞毒性表现。通过血小板粘附实验考察不同氮含量的高氮无镍奥氏体不锈钢材料的血液相容性;通过MTT实验和细胞粘附实验考察不同氮含量的高氮无镍奥氏体不锈钢材料的细胞相容性。结果表明,不同氮含量的高氮无镍奥氏体不锈钢材料对血小板粘附的影响不显著;不同氮含量的无镍不锈钢材料对成骨细胞的生长、形态和增殖不构成伤害,且氮含量对细胞的粘附影响并不显著;细胞毒性实验表明,高氮无镍奥氏体不锈钢和对照组钛合金材料性能稳定,对成骨细胞的生长没有产生明显的毒副作用。     

Diffusion bonding of titanium alloy to stainless steel wire mesh

Abstract

The feasibility and appropriate processing parameters of diffusion bonding of titanium alloy to stainless steel wire mesh directly and with a nickel interlayer have been investigated. The microstructures of the diffusion bonded joints were observed by optical microscopy, scanning electron microscopy, X-ray diffraction, and electron probe microanalysis and the main factors affecting diffusion bonding were analysed. The maximum shear strengths of the joints were 72 and 148 MPa for direct bonding and indirect bonding using a nickel interlayer respectively. Atomic diffusion and migration between titanium and iron are effectively prevented by adding pure nickel as the interlayer metal, and a firm joint is obtained.     

Al-Cu双金属复合结构的扩散连接试验研究

应用扩散连方法进行了Al-Cu双金属复合结构的试验研究，比较了不同的焊接工艺，材料组合以及母材状态情况Al合金与Cu的连接性，观察了接头区域的微观组织结构，研究表明，固相扩散连接是一种适用于异种材料连接的有效方法，通过在连接区域形成Al-Cu金属间化合物，达到Al和Cu的有效连接，材料组合，母材原始状态以及连接工艺参数对Al合金与Cu的扩散连接存在着明显的影响。表面镀Ni工艺不但能够有效阻止Al和Cu之间形成脆性相，而且Al和Ni之间形成了良好的扩散连接，改善了接头性能。     

Diffusion Bonding Technology of a Titanium Alloy to a Stainless Steel Web With an Ni Interlayer

The probability and appropriate processing parameters for diffusion bonding of a titanium alloy to a stainless steel web with an Ni interlayer have been investigated. The microstructure of the diffusion bonding joint has been observed by microscopy, SEM, and EPMA, and the main factors affecting diffusion bonding have been analyzed. The results show that atom diffusion and migration between Ti and Fe or C are effectively prevented by adding pure Ni as the interlayer metal, and a firm joint is obtained. When products were diffusion bonded, the relationship of exerting pressure and deformation is analyzed. A method of controlling deformation and attaining nondeformation bonding has been proposed. The optimum parameters are as follows: bond temperature is 850°C, bond-specific stress is 10MPa bond time is 10–15 min, and difference between ring-shaped bonding area radii D-d is 1–1.5mm.     

Vacuum hot roll bonding of titanium alloy and stainless steel using nickel interlayer

Abstract

Vacuum hot roll bonding of titanium alloy and stainless steel using a nickel interlayer was investigated. No obvious reaction or diffusion layer occurs at the interface between stainless steel and nickel. The interface between titanium alloy and nickel consists of an occludent layer and diffusion layers, and there are the intermetallic compounds (TiNi₃, TiNi, Ti₂Ni and their mixtures) in the layers. The total thickness of intermetallic layers at the interface between titanium alloy and nickel increases with the bonding temperature, and the tensile strength of roll bonded joints decreases with the bonding temperature. The maximum tensile strength of 440·1 MPa was obtained at the bonding temperature of 760°C, the reduction of 20% and the rolling speed of 38 mm s^–1.     

DD32单晶高温合金过渡液相扩散连接

为了提高DD32单晶高温合金过渡液相(TLP)扩散焊接头的力学性能,采用扫描电镜(SEM)和能谱分析仪(EDS)研究接头微观组织,TLP扩散焊过程中基体组织的变化,以及持久过程中基体组织的变化。结果表明,接头由连接区和基体区所组成,未发现明显的扩散区特征。连接区由等温凝固区和残余液相区组成。TLP扩散焊过程对基体组织有重要影响,接头需进行焊后热处理。此外,在持久过程中基体内产生了N型筏。控制TLP扩散焊接头内晶界的形成,可以有效提高接头力学性能。     

钨铜合金与纯铜焊接接头的电阻率测试

分别用真空扩散焊、真空钎焊和空气中钎焊3种方法进行了钨铜合金与纯铜的焊接,研究了不同连接方法对接头电阻率的影响。结果表明:真空钎焊和真空扩散焊较容易实现钨铜合金与纯铜的连接,但在空气中钎焊时接头较容易出现焊接缺陷,因而造成3种接头的电阻率不同。真空扩散焊接头的电阻率最低,与钨铜合金的电阻率接近,空气中钎焊接头的电阻率最高。当接头的导电性是最关键指标时,应首选真空扩散焊方法完成连接;如果对导电性要求不是很苛刻可以选择真空钎焊,其他情况在空气中钎焊即可。     

Diffusion bonding of zirconia to silicon nitride using nickel interlayers

The possibilities of diffusion bonding of zirconia to silicon nitride using a nickel interlayer were studied by carrying out bonding experiments under various processing conditions. The process parameters considered were temperature, bonding pressure and interlayer thickness. The optimal process conditions were determined by evaluating the mechanical strength using shear strength testing. It was found that the bonding is optimal in the temperature range 1000–1100°C. The bond strength appears to be independent of the bonding pressure and interlayer thickness if threshold values are exceeded (bonding pressure >14 MPa, interlayer thickness >0.2 mm). At the Si3N4 Ni interface, Si3N4 decomposes, forming a solid solution of silicon in nickel. At the ZrO2–Ni interface, no reaction was observed. © 1998 Kluwer Academic Publishers     

TiAl合金与高温合金的扩散焊接头组织及性能

采用直接扩散焊和加中间层的扩散焊方法进行了TiAl合金和高温合金异种材料组合的连接实验。在1000℃/20MPa/1h规范下直接扩散焊获得的TiAl/GH2036接头组织中存在大量未焊合的孔洞,接头室温剪切强度平均值仅有16MPa。采用Ti-Zr-Cu-Ni合金作为中间层在935℃加压3MPa保温10min和1h进行了TiAl/GH3536组合接头的液相扩散焊,获得的扩散焊缝中含有Ti3Al,NiTi等多种物相,中间层合金与两侧母材发生作用形成了具有一定厚度的反应层。在935℃/3MPa/1h规范下获得了与两侧母材结合良好的无缺陷扩散焊接头,室温剪切强度达到125MPa。     

Diffusion Bonding of Ti_3Al Base Alloy

: The effects of diffusion bonding temperature and holding time on the joint strength of Ti3Al base alloy has been investigated in this paper. The shear strength of Ti-14Al-21Nb-3Mo-V alloy diffusion bonding joint under pressure of 12 MPa at 990℃ for 70 min was obtained to 797.6 MPa which approaches the base material strength. In addition, a short-time diffosion bonding process was studied in order to decrease the bonding cost. With the deformation of the specimens of 2.5% and the bonding temperature of 990℃ for 15 min, the bonding strength could reach 801 MPa.     

Interfacial Microstructure of Diffusion Bonded Inconel 738 and Ferritic Stainless Steel Couple

In this study,Inconel 738 alloy was diffusion bonded to a ferritic stainless steel.The effect of bonding temperature on the microstructural development across the joint region was investigated.Following the diffusion bonding,conventional characterization techniques such as scanning electron microscopy(SEM),energy dispersive X-ray(EDX) and microhardness were used to examine the interfacial microstructure.It was seen that bonding temperature was effective on the diffusion of Ni from Inconel 738 to ferritic st...