Mechanical Performances and Failure Modes of Direct Diffusion Bonding Joints of 316L Stainless Steel

2006 ◽  
Vol 324-325 ◽  
pp. 979-982 ◽  
Author(s):  
Zi Liang An ◽  
Shan Tung Tu

Direct diffusion bonding of 316L stainless steel was performed at 850-1100°C for 1-3 h under a pressure of 10MPa in this study. The effect of bonding temperature and holding time on mechanical performances of the joints was investigated. Tensile tests were conducted to evaluate strength and elongation of the joints at room temperature and elevated temperature of 550°C. The microstructure and fracture surfaces of the joints were examined by optical microscope (OM) and scanning electronic microscope (SEM). The results indicated that the elongation of the joints increased with the increase of bonding temperature and holding time. However, overlong holding time had a side effect on the strength of the joint. Moreover, the change of the mechanical properties was closely related to the variation of the microstructure of the joints. The X-ray diffraction (XRD) analysis revealed that FeCr and Fe0.64Ni0.36 were formed at the DB6 joint during bonding process. It is suggested that FeCr should be detrimental to the improvement of high temperature strength of the joint.

Author(s):  
Gustavo Nuernberg ◽  
Grégori Rosinski ◽  
Priscila Gonçalves ◽  
Marcus Mortean ◽  
Regis Henrique Goncalves e Silva ◽  
...  

2015 ◽  
Vol 56 (10) ◽  
pp. 1683-1687 ◽  
Author(s):  
Takashi Harumoto ◽  
Osamu Ohashi ◽  
Hiroki Tsushima ◽  
Miho Narui ◽  
Kensaku Aihara ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7544
Author(s):  
Zhentao Wang ◽  
Shanglei Yang ◽  
Yubao Huang ◽  
Cong Fan ◽  
Zeng Peng ◽  
...  

In this paper, 316L stainless steel powder was processed and formed by selective laser melting (SLM). The microstructure of the sample was studied using an optical microscope, and the fatigue failure of the sample and the characteristics of crack initiation and propagation were analyzed, providing a research basis for the application of SLM-316L. Due to the influence of microstructure and SLM process defects, the fatigue cracks of SLM-316L mainly emerged due to defects such as lack of fusion and pores, while the cracks of rolled 316L initiated at the inclusions near the surface of the specimen. After fatigue microcrack initiation of the SLM-316L specimen, due to the existence of shear stress and tear stress, the crack tip was passivated and Z-shaped propagation was formed. The existence of internal defects in SLM-316L made the microcrack initiation random and diverse. At the same time, the existence of defects affected the crack propagation in the form of bending, bifurcation and bridge, which made the main crack propagation deviate from the maximum load direction.


2019 ◽  
Vol 15 (6) ◽  
pp. 1037-1052
Author(s):  
A. Arun Negemiya ◽  
S. Rajakumar ◽  
V. Balasubramanian

Purpose The purpose of this paper is to develop an empirical relationship for predicting the strength of titanium to austenitic stainless steel fabricated by diffusion bonding (DB) process. Process parameters such as bonding pressure, bonding temperature and holding time play the main role in deciding the joint strength. Design/methodology/approach In this study, three-factors, five-level central composite rotatable design was used to conduct the minimum number of experiments involving all the combinations of parameters. Findings An empirical relationship was developed to predict the lap shear strength (LSS) of the joints incorporating DB process parameters. The developed empirical relationship was optimized using particle swarm optimization (PSO). The optimized value discovered through PSO was compared with the response surface methodology (RSM). The joints produced using bonding pressure of 14 MPa, bonding temperature of 900°C and holding time of 70 min exhibited a maximum LSS of 150.51 MPa in comparison with other joints. This was confirmed by constructing response graphs and contour plots. Originality/value Optimizing the DB parameters using RSM and PSO, PSO gives an accurate result when compared with RSM. Also, a sensitivity analysis is carried out to identify the most influencing parameter for the DB process.


2015 ◽  
Vol 787 ◽  
pp. 495-499 ◽  
Author(s):  
K. Dheenadayalan ◽  
S. Rajakumar ◽  
V. Balasubramanian

In this investigation, Commercially Pure (Cp) titanium was diffusion bonded to AA7075-T6 aluminium alloy at various temperatures of 450, 475, 500, 525 and 5500C, bonding pressure of 17, MPa and holding time of 40 minutes was applied during the diffusion bonding. The effects of reaction temperature, Bonding time and atmosphere on the diffusion welding characteristics of titanium and aluminum have been studied. The maximum Lap shear strength was found to be 89 MPa for the specimen bonded at the temperature of 525°C, Bonding Pressure 17 MPa and Holding time for 40 min.


2014 ◽  
Vol 548-549 ◽  
pp. 310-315
Author(s):  
W.M.F.W. Mohamad ◽  
M.Z. Selamat ◽  
B. Bundjali ◽  
M. Musa

This present paper is aims to study the influence of cold rolling process on the microstructure and corrosion behaviors of 316L stainless steel using potentiodynamics polarization testing techniques. The steel with initial thickness of 2.0 mm was unidirectional cold rolled to 10%, 30% and 50% reduction in thickness. The corrosion behaviors of the cold rolled steels were evaluated in phosphate buffered saline (PBS) as their simulated body fluids environment. The pH and temperature of the solution was maintained at 7.31 and 37°C and took approximately 5 hours for each individual test. The microstructure observations of the steels were studied using optical microscope and scanning electron microscopy (SEM). The results showed that the cold rolling process has modified the microstructure of 316L stainless steel by producing extensive surface defects. The microstructure modifications of the cold-rolled steel caused to enhance the corrosion resistance by lowering its corrosion rate to 23% and reduce the pitting resistance by lowering its breakdown potential to 61%. The pit corrosion was extensively appeared after reaching the breakdown potential.


2011 ◽  
Vol 121-126 ◽  
pp. 10-14
Author(s):  
Fei Lin ◽  
Tie Peng Li ◽  
Lu Lu Sun ◽  
Qing Sen Meng

In this investigation a study on vacuum diffusion bonding of as-extruded AZ31 magnesium alloys was carried out according to atomic diffusion theory. The bonding quality of the joints was checked by microstructure analysis, shear test and micro-hardness testing. The results showed that the diffusion temperature and holding time had a great effect on the the bonding quality of the joints. The maximum of joint shear strength was 76.2MPa with the bonding temperature being 420°C and the holding time reaching 90min.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1129-1133
Author(s):  
Hui Li ◽  
Xuan Wang ◽  
Yong Zhu ◽  
Peng Cheng Zhang

In order to provide the best technic parameter for hot pressing, the distributions of Fe and Be near the Be and 00Cr17Ni14Mo2 stainless steel (Be/SS) diffusion bonding interface under different technic parameter were simulated by the finite element method and measured by means of scanning auger microspectroy (AES). The simulated results were compared with experimental value, The distributions of Fe and Be near the Be/SS diffusion bonding interface and the relationships between the width of diffusion layer, the heating temperature, the holding time and the pressure were also discussed. The results indicate that under the condition of heating temperature 1323K and 1023K with diffusion pressure 60MPa and holding time 7200s, respectively, the simulated distributions of Fe and Be near the Be/SS diffusion bonding interface fit with the experimence values, and the width of diffusion layer at 1323K is about 2.5 times the one at 1023K. Under the condition of heating temperature 1023K with holding time 7200s, the width of diffusion layer measured at 30MPa, 40MPa, 50MPa and 60MPa is fit well with the simulated results and the relationship between the width of diffusion layer (x/μm) and the diffusion pressure (p/MPa) follows the eqution 0fx=-1.5×10-2p2+2.8275p-0.1575. Under the condition of heating temperature 1023K with diffusion pressure 60MPa, the simulation curve between the width of diffusion layer (x/μm) and the holding time (t/s) follows the eqution 0fx=10t3-60.571t2+135.64t+0.2143.


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