Showing 3 results for Rasouli
I. Rasouli, M. Rafiei,
Volume 4, Issue 2 (Journal OF Welding Science and Technology of Iran 2019)
Abstract
In this research, microstructure and mechanical properties of AISI316 to AISI430 dissimilar joint were investigated. For this purpose, GTAW process using ER316L and ER2209 filler metals with diameter of 2.4 mm was used. The microstructure and fracture surface of the welded samples were characterized by optical microscopy and scanning electron microscopy. Also the mechanical properties of the welded samples were evaluated by tension, impact and microhardness tests. It was found that the microstructure of the welded sample with ER316L filler metal contained Widmanstatten austenite with inter-dendritic and lathy ferrites. Also, in the welded sample with ER2209 filler metal, Austenite phase in ferrite matrix was seen. In tension test, all samples were fractured from AISI430 side of the joint in a ductile manner. ER2209 weld metal indicated low impact energy of about 27 J, while ER316L weld metal indicated higher impact energy of about 43 J. The fracture surface in both welded samples indicated brittle fracture mode. The microhardness of the weld metal of the welded sample with ER316L filler metal was higher than the welded sample with ER2209 filler metal due to the presence of alloying elements, proper distribution of delta ferrite and finer microstructure.
Dr Homam Naffakh-Moosavy, Eng. Ali Rasouli,
Volume 7, Issue 2 (Journal OF Welding Science and Technology 2022)
Abstract
In this research similar joining of NiTi shape memory alloy was studied. For this purpose, NiTi alloy in the form of wires with circular cross section possessing martensitic phase structure at room temperature was used. By utilizing Nd:YAG pulsed laser welding method followed by optimizing its technical parameters, a defectless joint in terms of appearance and metallurgical properties was obtained. In the next step, the effect of various pulsed laser duration time on properties of the obtained similar joint of NiTi was investigated. Moreover, the resultant microstructures were studied using optical microscope (OP) and Scanning Electron Microscope (SEM) equipped with chemical analysis of EDS. Furthermore, the samples prepared under different pulsed laser duration time conditions were characterized by using tensile and micro-hardness tests. Investigating the results of the performed evaluations revealed that higher levels of heat input has resulted in grain growth, dissolution of precipitations as well as reduction in hardness and ultimate tensile strength of the samples in the joint zone.
M. Foumani, H. Naffakh-Moosavy, A. Rasouli, H. Aliyari,
Volume 8, Issue 1 (Journal OF Welding Science and Technology 2022)
Abstract
Surface roughness in the welding processes is one of the important parameters in the laser welded metal connections which affects laser beam absorption directly. When the laser beam is irradiated to the surface of the base metal, the surface roughness plays an important role in the amount of beam absorption and the amount of melting achieved and directly affects the penetration depth. The main purpose of this study is to investigate the effect of roughness mentioned above in the equal parameter for this widely used aluminum alloy. Microstructural Surveys were performed on three different roughness levels of the sample and the results obtained from the analysis of samples by optical microscope (OM), atomic force microscope (AFM) and Scanning electron microscopy (SEM) analysis showed that, increasing the surface roughness up to Ra = 0.16 micrometer, caused the greater degree of beam engagement by the surface grooves, hence more concentration of the beam photons and more melting obtained, so the depth of penetration increases by consuming a lower amount of energy.
