Amir Rasti
@modares.ac.ir
Department of Mechanical Engineeering
Tarbiat Modares University
RESEARCH, TEACHING, or OTHER INTERESTS
Mechanical Engineering, Industrial and Manufacturing Engineering, Management Information Systems
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Mohammad Yazdani and Amir Rasti
Elsevier BV
Hamed Hassanpour, Amir Rasti, Javad Hashemi Khosrowshahi, and Sina Sabbaghi Farshi
Elsevier BV
Amir Rasti, Hamed Hassanpour, Sina Sabbaghi Farshi, and Javad Hashemi Khosrowshahi
Springer Science and Business Media LLC
J. Hashemi Khosrowshahi, M. H. Sadeghi, and A. Rasti
Springer Science and Business Media LLC
Hamed Hassanpour, Amir Rasti, Mohammad Hossein Sadeghi, and Javad Hashemi Khosrowshahi
Informa UK Limited
Abstract In this research, the effects of high speed milling on the main surface integrity characteristics, including surface roughness and topography, microhardness, white layer thickness, and surface chemical composition of Ti-6Al-4V were empirically studied. Totally, 18 experiments were carried out using a full factorial design of experiments method in the presence of minimum quantity lubricant. The results showed that by using high speed milling, it is possible to reach the surfaces with a higher quality and surface roughness of approximately 0.2 μm. Also, it was discovered that the microhardness variation with cutting speed has a dual nature. The maximum microhardness was obtained at the cutting speed of 375 m/min and the feed rate of 0.08 mm/tooth, which showed a 57% increase compared with the bulk material. In addition, by using the cutting speed of 450 m/min, the depth of heat-affected layer and work hardening effects declined up to 75% in comparison with the cutting speed of 300 m/min.
Amir Rasti, Mohammad Hossein Sadeghi, and Sina Sabbaghi Farshi
Springer Science and Business Media LLC
Amir Rasti, Mohammad Hossein Sadeghi, and Sina Sabbaghi Farshi
Elsevier BV
Amir Rasti, Mohammad Hossein Sadeghi, and Sina Sabbaghi Farshi
Springer Science and Business Media LLC
Hamed Hassanpour, Mohammad H. Sadeghi, Hamed Rezaei, and Amir Rasti
Informa UK Limited
In the present study, the effects of various cutting conditions on the surface integrity of titanium parts (Ti6Al4V) have been investigated during the micromilling process. In addition, to have a better understanding of the results, the cutting force was measured. The experiments were performed in the Minimum Quantity Lubrication condition using the tungsten carbide microtool with 0.5 mm in diameter. Micromilling parameters including feed rate, spindle speed and axial depth of cut were considered as process inputs, each in three levels, and their effects on the surface roughness, burr width, surface and in-depth microhardness as well as mean cutting force were evaluated. In the range of experimental parameters and according to the results, cutting speed and feed per tooth had the highest impact on the surface integrity characteristics of this alloy, respectively. While most research works concentrated on the feed per tooth as the main parameter in the micromilling process, the result of the study showed that the variation of cutting speed as one of the influential factors could also be used in order to decrease cutting forces and to improve surface quality.
Hamed Hassanpour, Mohammad H. Sadeghi, Amir Rasti, and Shaghayegh Shajari
Elsevier BV
A Rasti, I Sattarifar, M Salehi, and V Karimnia
SAGE Publications
Structural weight is one of the key criteria for vessels used in marine industries. The use of stiffeners and stringers strengthens the structure with the addition of a minimum weight. In cylindrical pressure vessels under hydrostatic pressure, mostly ring-type stiffeners are used. In order to join a stiffener ring to the vessel, welding is a conventional method. However, this process generates welding residual stresses and distortions, which can be added to external loads and cause structural failure. This study aims to develop a comprehensive simulation tool to predict distortions and residual stresses generated due to fillet-welded stiffener ring on an aluminum cylinder. Therefore, a hybrid numerical simulation approach has been employed. The simulation strategy has been implemented by using finite element software ANSYS enhanced with a number of subroutines. Results showed that the stiffener ring changes distortion trend in all orientation, especially in the radial direction with a reduction up to 15% in stiffener ring position. On the other hand, the radial residual stress was negligible and the hoop residual stress was tensile in the fillet weld region, with half of the base metal tensile strength magnitude, except in the start and the end of weld. Moreover, the axial residual stresses in the weld region on inner and outer surface of vessel in stiffener ring position were tensile and compressive, respectively.
S. Elhami, M. R. Razfar, M. Farahnakian, and A. Rasti
Springer Science and Business Media LLC