Search published articles


Showing 4 results for Interface
Effect of diffusion bonding temperature on microstructure properties of Zr/Ti interlayer in the diffusion bonded joints of Zr702 to A516 steel
A. Pourjafar, R. Dehmolaei, R. Alavi Zaree, Kh. Ranjbar, M.r. Tavakoli Shoushtari,
Volume 8, Issue 2 (1-2023)
Abstract
In this study, the effect of temperature on the microstructure and reactive layer at the interface between the Ti interlayer and the base metal related to the diffusion bonding of Zr702 to A516 low alloy steel was investigated. The joining was done using the spark plasma sintering technique at temperatures of 900, 950 and 1000°C for 30 minutes. Field Emission Scanning Electron Microscope (FESEM) equipped with EDS analysis was used to investigate the microstructure of the interfaces in various joints. Investigations showed that at all temperatures, with the diffusion of atoms and the formation of a reactive layer between the Ti interlayer and Zr702, no intermetallic phases, cracks, porosity and discontinuities were formed at their interfaces. . It was found that increasing the bonding temperature did not cause the formation of new phases and compounds in the interface and only increased the thickness of the reaction layer. The measurement of the thickness of the reactive layer showed that the maximum and minimum amounts of diffusion were 84 microns at 1000 °C and 64 microns at 900 °C respectively

Influence of Rolling on Microstructure and Mechanical Properties of Bronze-Steel Explosive Welded Sheets
Gh. Khalaj, E. Asadian,
Volume 8, Issue 2 (1-2023)
Abstract

In this paper, the microstructure and mechanical properties of the plain carbon steel-bronze interface of explosive welding and rolling were investigated. Explosive connection was done at two stop distances and with two different thicknesses of explosive material. Rolling of the welded composite was done at both ambient and preheated temperatures of 300 °C and with a constant thickness reduction of 33.3%. The results showed that the wave interface of the steel-bronze connection includes different parts. By rolling, the connection interface was stretched and flattened and the vortex areas were compressed together and in some cases entered the steel field. The steel particles separated from the background along the wave crest and remained as isolated islands in the bronze background. On the other hand, in the areas near the vortex, a part of the bronze flying metal was caught under the wave and was observed as islands separated from the bronze background inside the steel. Porous areas were crushed and compressed as a result of rolling. The rolling force and temperature had partially removed the diffusion barriers and a metal bond had been formed between bronze and steel. During the connection, the voids and shrinkage pores were pressed together due to rolling and the separate borders were close to each other. Explosive joining and cold rolling had increased the hardness in the interface, and hot rolling has led to a decrease in the hardness in the interface. In the hardness test, the welding samples are arranged in the order of the highest impact energy. The effects of welding parameters remain after cold and hot rolling and the hardness rating does not change.


Effect of post weld heat treatment on the structure and mechanical properties of explosive welding of austenitic steel 321 - aluminum 1050 - aluminum 5083
Gh. Khalaj, A. Fadaei,
Volume 9, Issue 1 (5-2023)
Abstract
In this research, the effect of post weld heat treatment on the microstructure and mechanical properties of the three-layer explosion welding joint of austenitic steel 321-aluminum 1050-aluminum 5083 was investigated. The welded samples were heat treated at 250 and 350°C for 10000 seconds. The structure and properties were investigated using optical microscope, scanning electron microscope, microhardness measurement and shear-compressive strength. The results showed that in all conditions, the interface of aluminum 5083-aluminum 1050 was smooth and with complete continuity; However, the interface between stainless steel 321 and aluminum 1050 had a reaction layer with variable and discontinuous thickness. During the heat treatment, the thickness of the interface layer increases according to the diffusion kinetics and reaches 18.6 microns in the maximum value. With the increase of heat treatment temperature, the average concentration of aluminum in the reaction layer of the interface increased from 85% to more than 90%, but the concentration of iron decreased from 10% to less than 5%. Also, shear-compressive strength decreases from 94.6 to 56.7 MPa.

Investigation of the Joint Interface in Explosive Welding of Austenitic Stainless Steel 321 - Aluminum 1050 - Aluminum 5083 after Heat Treatment
Gh. Khalaj, J. Khalaj, F. Soleymani,
Volume 10, Issue 1 (6-2024)
Abstract
In this study, the microstructure of the joint interface in three-layer explosive welding of austenitic stainless steel 321 - aluminum 1050 - aluminum 5083 was examined before and after heat treatment. The welded samples were subjected to heat treatment at temperatures of 250°C and 350°C for durations of 1000, 3000, and 10000 seconds. Microstructural analysis was performed using optical microscopy and scanning electron microscopy. The results revealed that under all conditions, the Joint Interface of aluminum 5083 - aluminum 1050 exhibited a flat and defect-free structure. With increasing standoff distance, the Joint Interface of stainless steel 321 - aluminum 1050 transitioned from a smooth to a wavy pattern, and the average layer thickness increased from 4.95 μm to 6.7 μm. During heat treatment, the layer thickness in the Joint Interface increased proportionally to the diffusion kinetics, reaching maximum values of 18.56 μm and 15.02 μm for samples with standoff distances of 6.75 mm and 6 mm, respectively. The activation energies for diffusion were calculated as 46.6 kJ/mol and 42.4 kJ/mol, and the diffusion constants were 142.2 ms-1  and 45.3 ms-1 for the same samples.


 
Page 1 from 1     

© 2024 CC BY-NC 4.0 | Journal of Welding Science and Technology of Iran

Designed & Developed by : Yektaweb