Interface Microstructure and Strength Properties of the Diffusion-Bonded Joints of Titanium ∣Cu Interlayer ∣ Stainless Steel

Abstract

In the present study, copper was used as an intermediate material in diffusion bonding between titanium and stainless steel. The process was carried out in the temperature range of 850°C to 1000°C for 60 minutes and at 900°C for 30 to 150 minutes under the compressive stress of 3 MPa in a vacuum. The effects of temperature and time on the microstructure of Ti OECu OE stainless steel diffusion-bonded joints were studied. The interface microstructures of the bonded assemblies were observed in optical and scanning electron microscopes and an electron probe microanalyzer. Formation of various types of reaction products near the interface was detected using the X-ray diffraction technique. The maximum tensile and shear strength of~101 pct of that of Ti and of~86 pct of that of Ti, respectively, along with~8.5 pct elongation, were obtained at 900°C for 60 minutes. Observation of fracture surfaces demonstrates that failure takes place through the SS-Cu interface.

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

“…The maximum tensile strength of the diffusion bonded joint between commercially pure Ti and 304 SS is previously reported to be 322 MPa. 13 Apparently, significant improvement in bonding strength is achieved in the present study. Fracture morphology observations of SS side are given in Fig.…”

“…The tensile strength is limited, and cleavage patterns are frequently observed on the fracture surfaces, clearly indicating the brittleness of the IMCs. 1,[8][9][10][13][14][15] For instance, when Ti is diffusion bonded to SS using a Ni interlayer, TiNi 3 , TiNi and Ti 2 Ni are formed at the Ni/ Ti interface. Upon tensile loading, fracture takes place through the Ti x Ni y IMC layers and the joint strength is only 270 MPa.…”

“…Consequently, a wide spectrum of alternative joining techniques, particularly the solid state ones specific to this dissimilar joining couple, has been developed. [2][3][4][5][6][7][8][9][10][11][12][13] Of the techniques available, diffusion bonding has been demonstrated to be a feasible approach to eradicate the problems associated with fusion welding and has emerged as a near net shape forming processing. 1,[8][9][10] The main hindrance to achieve a high strength diffusion bonding of Ti to SS is the fundamental brittleness owing to the formation of intermetallic compounds (IMCs) at the interfaces of the joint.…”

Evolution of Interface Microstructure and Mechanical Properties of Titanium/304 Stainless Steel Diffusion Bonded Joint Using Nb Interlayer

“…12) In a prior research work, the present authors improved the strength and ductility of the diffusion bonded joints between titanium and type 304 stainless steel using nickel (Ni) or copper (Cu) individually as an intermediate materials. 13,14) In this respect niobium can also be considered as a intermediate materials to improve the mechanical properties. Phase diagram shows that pure titanium and pure niobium does not form any intermetallic compound.…”

Microstructure and Mechanical Properties of Joints of Titanium with Stainless Steel Performed using Nickel Filler

“…Such types of joints have applications in aerospace, chemical and nuclear industries [1][2][3][4]. Conventional fusion welding is not a feasible technique to join these materials due to the different problems like formation of stress concentration at the bond interface and development of chemical heterogeneities [5][6][7]. Hence, diffusion brazing offers a feasible solution to overcome these problems [8].…”