Showing 11 results for Transient Liquid Phase
A. Anbarzadeh, H. Sabet,
Volume 3, Issue 1 (8-2017)
Abstract
The aim of this study is investigation of TLP variables on microstructure and mechanical properties of Al2024 to Ti-6Al-4V bonding for TLP joint. For this purpose, the sheets were prepared with dimension of 130×32×3 mm from Ti-6Al-4V and Al2024 alloys and 50µm thick Sn-5.3Ag-4.2Bi foil as interlayer. Sn-5.3Ag-4.2Bi foil prepared with dimension of 32×25 mm. Two alloys was joint together by process of Successive stage Transient Liquid Phase (S-TLP). This process is contains two stages. The first one is Transient Liquid Phase (TLP) of Ti-6Al-4V and the second stage is diffusion bonding of Al2024 to Ti-6Al-4V. In the first stage, TLP process was used for joining of Ti-6Al-4V to Ti-6Al-4V samples. This process carried out under argon gas at 2 atmosphere and at 620 °C. After the end of first stage, the samples were broken from the joint region and then, the obtained surface was jointed to Al2024 with new interlayer. In the second stage, that is soldering, the samples were placed in furnace under argon gas at 2 atmosphere and at 453 °C. Maximum tensile strength of diffusion bonding was about 62 Mpa.
R. Abdolvand, M. Atapour, M. Shamanian, A. Allafchian,
Volume 3, Issue 2 (1-2018)
Abstract
Transient liquid phase bonding of UNS S32750 super duplex stainless steel to AISI 304 austenitic stainless steel using BNi-2 interlayer was carried out at 1050 oC for 45 min. Microstructure analyses of the joint were carried out using optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Microhardness indentation and shear strength test were performed to assess mechanical behavior of the joint. No eutectic contents was seen at the joint and thus Isothermal solidification was completed at 45 min bonding time. The shear strength of the joint was about 0.7 of duplex stainless steel shear strength. Froctographic studies revealed that the fracture mode was completely ductile in the case of the joint made at bonding time of 45 min.
A. Khorram, A. Davoodi Jamalooei, A. Jafari,
Volume 3, Issue 2 (1-2018)
Abstract
In this study, microstructural evaluation and mechanical properties of similar TLP bonded of Inconel 600 by using of BNi-2 interlayer were investigated. The bonding tests were carried out at 1050°C and 1100°C for 5-45 min which homogenization treatment was performed on the best of the bonded samples. Results showed that Ni-B eutectic compound was formed in the a-thermally solidification zone (ASZ) of the bonded sample at 1050°C. In addition to existence of the Ni-B compound, Cr-B was observed in the ASZ of the bonded sample at 1100°C. Ni-B and Ni-Cr-B were formed in the diffusion affected zone (DAZ). TLP bonded sample at 1050°C for 45min including discontinuous areas of ASZ in isothermal solidification zone (ISZ) was the best bonded sample. Homogenization process was carried out on this sample caused to elimination of the eutectic compounds, completely. Mechanical investigation revealed that due to existence of the intermetallic compounds in the ASZ and DAZ, value of hardness for this region were about 510 and 311 HV, respectively. Whit elimination of the intermetallic compounds by performing of homogenization treatment, mechanical properties of the boding region were improved.
S. Ghaderi, F. Karimzadeh, A. Ashrafi,
Volume 5, Issue 2 (1-2020)
Abstract
In the present study, the effect of time and base metal microstructure on the Transient Liquid Phase (TLP) bonding of 304L stainless steel was studied. TLP was performed at 1050 0C for 5 and 60 minutes on the coarse grain austenitic and martensitic microstructure using BNi-2 interlayer. To prepare martensitic microstructure, as-received 304L was rolled at -15 0C up to 80% rolling reduction. TEM analysis was proved that the microstructure of 80% rolled samples consisted of two different morphologies of martensite namely as lath-type and dislocation cell type martensite. It was observed that the structure of bonded zone after 5 min has consisted of isothermally solidified zone (ISZ) containing γ solid solution and athermally solidified zone (ASZ) containing complex boride phases. Meanwhile, after 60 min of heating, the structure of bonded zone completely solidifies isothermally. The obtained results also showed that the martensitic microstructure considerably effect on the width of diffusion affected zone (DAZ) which was related to the reversion of martensite to ultrafine grain austenite during heating.
S. A. Beheshti Bafqi, M. Mosallaee,
Volume 6, Issue 2 (12-2020)
Abstract
In the present study, the transient liquid phase bonding of AISI 2205 dual phase stainless steel with amorphous BNi-3 interlayer was carried out. Based on the initial experimental and analytical studies, the parameters of temperature and bonding time were determined. In order to investigate the effect of bonding temperature on the microstructural changes of the joint, bonding was performed in the temperature range of 1050-1200℃ for 20 min. The microstructural and phase analyses indicated the completion of isothermal solidification and the formation of a uniform Ni-solid solution in the bonding zone centerline. The interdiffusion between the bonding zone and the adjacent base metal resulted in the formation of boride and nitride intermetallic compounds in the base metal adjacent to the bonding zone, which the area fraction of this intermetallics significantly decreased with increasing bonding temperature from 1050℃ to 1200℃ (reduction of the intermetallic area fraction from 85% to 40%). Evaluation of shear strength of samples showed that despite the completion of isothermal solidification in all samples and shear strength of bonded samples significantly depends of amount and morphology of intermetallic compounds on the transient liquid phase bonding shear strength. By increasing the bonding temperature to 1200℃ and reducing the area fraction of intermetallic compounds up to 40% of the shear strength of the samples increased from 450 MPa of TLP bonded specimen of 1050℃ to about 85% of base metal shear strength.
H. Tazikeh, S. E. Mirsalehi, A. Shamsipoor,
Volume 7, Issue 1 (8-2021)
Abstract
In this research, the effect of bonding temperature on the microstructure and mechanical properties of Inconel 939 super alloy by transient liquid phase bonding method. For this purpose, the middle layer of MBF20 with a thickness of 50 microns and three temperatures of 1060 °C, 1120 °C, 1180 °C and a time of 45 minutes have been used. In order to evaluate the microstructure, a scanning electron microscope equipped with an elemental analysis system has been used. Vickers hardness test and shear strength test have been used to evaluate the mechanical properties. The research findings showed that with increasing temperature from 1060 °C to 1120 °C, the width of the athermal solidification zonedecreased from 38µm to 35µm and with increasing temperature at 1180 °C, the athermal solidification zone was completely removed and isothermal solidification zone was replaced. In addition, with increasing temperature, the hardness in the joint center decreases and the shear strength increases.
Dr Behzad Binesh, Dr Sima Mirzaei, Mr Amin Taghi-Ahari,
Volume 7, Issue 2 (1-2022)
Abstract
Transient liquid phase (TLP) bonding of AISI 304L stainless steel was carried out using BNi-2 amorphous interlayer. The microstructure of the joint area was studied by using optical and scanning electron microscopes and energy dispersive spectroscopy. The effect of bonding temperature (1030-1110 °C) was studied on the microstructure and corrosion behavior of the TLP bonded samples. Electrochemical corrosion resistance of the bonded samples was evaluated in 3.5% NaCl solution at room temperature. The mechanism of the microstructure formation and the solidification sequence at the joint area were discussed. Ni- and Cr-rich borides, Ni-Si-B compound and fine Ni3Si particles were identified in the γ-Ni matrix at the joint centerline. The microstructural investigations revealed that the solidification sequence of these phases is: L→ γ + L → γ + Ni boride + Cr boride + L → γ + Ni boride + Cr boride + Ni-Si-B Compound. The highest corrosion resistance was observed in the sample bonded at 1070 °C for 30 min, which is comparable to that of the as-received AISI 304L stainless steel. It was attributed to the bond region microstructure with a negligible amount of eutectic constituents formed in the athermally solidified zone.
A. Anbarzadeh, H. Sabet, A.r. Geranmayeh,
Volume 8, Issue 1 (8-2022)
Abstract
In this study, to bond AA2024 and AA6061 alloys to each other, three elements (Sn, Zn and Ga) were considered as interlayer elements in terms of atomic diffusion depth in the base metal and storage at 453°C for 2 days, 10 hours, 210 minutes, and 30 seconds that they were examined for atomic diffusion modeling. Finally, the two alloys were connected at a temperature of 453°C in a furnace environment under a vacuum of 7.5×10-13 Torr under a transient liquid phase process. The effect of changing the thickness of the interlayer on the connection of the two alloys are examined with practical tests such as metallography, SEM, the distribution map of the elements, hardness test, the linear scan of the elements at the joint, and tensile strength test in two modes, 1: investigating the effect of changing the thickness of the interlayer on strength, and 2: investigating the change in joint strength by increasing sample retention time in the furnace. As the thickness of the interlayer increases (from 20 to 70 μm), the bond strength decreases. The maximum tensile strength of joint with the 20 μm thickness Sn-5.3Ag-4.6Bi interlayer is 52 MPa.
M. M. Taghvaei, M. Shamanian, Behzad Niroumand, H. Mostaan,
Volume 8, Issue 2 (1-2023)
Abstract
Joining of Hastelloy C276 nickel-base superalloy to AISI316 Stainless Steel using BNi-2 interlayer performed by transient liquid phase process (TLP) at 1150°C for 5 and 30 minutes. Bonding microstructure was studied using an Optical microscope and a scanning electron microscope (SEM). Vickers hardness test and shear strength test have been used to evaluate the mechanical properties. Microstructural studies showed that at 5 and 30 minutes of bonding time, isothermal solidification is completely formed, and the Center of the joint is free of any eutectic intermetallic compounds. Also, Findings showed that the DAZ of Hastelloy C276 nickel-base superalloy contains rich borides of Ni, Cr, Mo, and W, and the DAZ of 316 austenitic stainless steel contains borides rich in Fe, Cr, and Ni.
Behnam Heidari-Dehkordi, Mahdi Rafiei, Mahdi Omidi, Mohsen Abbasi-Baharanchi,
Volume 9, Issue 2 (8-2024)
Abstract
In this study, 316L stainless steel and WC-10Co cermet were bonded by transient liquid phase process with BNi-2 interlayers with different thicknesses of 25 and 50 μm. The bonding process was conducted at 1050 °C for 1, 15, and 30 min. After bonding, the microstructure of the joints was examined using optical microscopy and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. Microhardness and tensile-shear tests were also performed to study the mechanical properties of the bonded samples. Microstructural analyses revealed that the formation mechanism of the solidified region in all samples was isothermal solidification, resulting in an isothermal solidification zone upon bonding. Additionally, the only phase present in the isothermal solidification zone was a nickel-based solid solution. In the diffusion-affected zone of the steel base material, complex borides formed regardless of the interlayer thickness. In the diffusion-affected zone of the WC-Co material, a brittle eta phase formed. Microhardness tests indicated that the maximum hardness in all samples was approximately 1100 Vickers, which was attributed to the presence of hard WC particles in the WC-Co base material. Furthermore, the highest tensile-shear strength, approximately 240 MPa, was observed in the bonded sample for 15 min with 50 μm thickness interlayer.
H. Zeidabadinejad, M. Rafiei, I. Ebrahimzadeh, M. Omidi, F. Naeimi ,
Volume 10, Issue 1 (6-2024)
Abstract
In this research, the transient liquid phase bonding of St52 carbon steel to WC-Co cermet using a copper interlayer with 50 μm thickness was done. For this purpose, samples were jointed to each other at a constant temperature of 1100 ºC and bonding times of 1, 15, 30, and 45 min. The microstructure of the joints was examined using an optical microscope and scanning electron microscope equipped with energy-dispersive X-ray spectroscopy. XRD analysis was also used to investigate the effect of bonding on the phase changes of the bonding area. Microhardness and tensile shear tests were also conducted to study the mechanical properties of the samples. Microstructural investigations showed the formation of three different zones including isothermal and athermal solidification zones and DAZ in the WC-Co base material side, which determine the characteristics of the samples. The isothermal solidification zone contained a Fe-rich solid solution and the athermal solidification zone contained a Cu-rich solid solution. η phase was not formed in the DAZ of WC-Co cermet at bonding times of 1 and 15 min. This phase was formed in the DAZ of WC-Co cermet by increasing the bonding time to 30 and 45 min. The microhardness studies showed that all samples had the same trend. Maximum microhardness was 1100 HV which was related to WC-Co base cermet and the lowest microhardness was about 220 HV which was related to steel base metal. Also, the maximum tensile-shear strength of the bonded samples was about 180 MPa for a bonded sample at a bonding time of 15 min, which was due to the increase in the volume fraction of iron-rich solid solution, as well as proper microstructural continuity and the presence of an optimal amount of copper-rich phase in the microstructure.
