The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Ali Shamsipur - One of the best experts on this subject based on the ideXlab platform.

  • transient liquid phase bonding of az31 magnesium alloy Metallurgical Structure and mechanical properties
    Journal of Manufacturing Processes, 2018
    Co-Authors: Sohrab Ghahri Saremi, Seyyed Ehsan Mirsalehi, Ali Shamsipur
    Abstract:

    Abstract In the present paper, AZ31 magnesium alloy was transient liquid phase bonded using aluminum interlayers (with two different thicknesses of 9 and 14 μm), two bonding temperature of 440 and 455 C and different holding times. Optical and scanning electron microscopies were employed to determine the progression of isothermal solidification. In addition, X-ray diffraction method was used to determine the formation of the brittle Al12Mg17 compound. The hardness was found to be higher at the joint center compared to the joint sides, which can be related to the eutectic Structure and high amount of intermetallic compounds at the center. The results showed that the 9 μm-interlayer led to greater shear strength, elongation and failure energy than the 14 μm interlayer, and the highest shear strength of ∼35 MPa was obtained for 75 min bonding time and 9 μm interlayer. The fracture surface evaluation revealed the presence of more plastic deformation for the joints made by the thinner interlayer.

  • investigation on Metallurgical Structure and mechanical properties of dissimilar al 2024 cu fsw t joints
    Transactions of The Indian Institute of Metals, 2017
    Co-Authors: Mostaan Lotfalian Saremi, Seyyed Ehsan Mirsalehi, Ali Shamsipur
    Abstract:

    In this research, T-joining of AA2024-T4 and commercially pure copper were performed successfully using friction stir welding. Effect of welding parameters on Metallurgical and mechanical characteristics of the joints was studied. For this purpose, tensile strength, microhardness, and macro- and microStructures of the joints were investigated. Also, the fracture surfaces were examined using XRD and SEM. The best results were obtained for the 1130 rpm rotation speed (ω) and 12 mm/min travel speed (v), with the UTS of 156 MPa (~70% of Cu strength). The microhardness test showed that TMAZ and base metal of Al side had the maximum hardness amounts (148 and 155 HV, respectively). Generally, increase in the ω2/v ratio caused the nugget zone and HAZ grain size to increase. The results revealed the formation of Al2Cu and Al4Cu9 intermetallic compounds in the border zone of the joints. The fractography results showed the occurrence of cleavage fracture in all the samples.

A.k. Lahiri - One of the best experts on this subject based on the ideXlab platform.

  • An online parallel controller for the runout table of hot strip mills
    IEEE Transactions on Control Systems Technology, 2001
    Co-Authors: R.k. Kumar, S.k. Sinha, A.k. Lahiri
    Abstract:

    In a hot strip mill, the strip is cooled by spraying water from top and bottom on the runout table (ROT), before the strip is coiled. The desired mechanical properties and Metallurgical Structure of the strip are achieved by controlling the cooling rate and temperature of the strip on the ROT. This paper describes a novel online parallel controller which incorporates both feedforward and feedback actions to control the temperature of the strip on the ROT. The performance of the proposed controller has been studied with the aid of a real-time simulator and is reported in this paper.

R.k. Kumar - One of the best experts on this subject based on the ideXlab platform.

  • An online parallel controller for the runout table of hot strip mills
    IEEE Transactions on Control Systems Technology, 2001
    Co-Authors: R.k. Kumar, S.k. Sinha, A.k. Lahiri
    Abstract:

    In a hot strip mill, the strip is cooled by spraying water from top and bottom on the runout table (ROT), before the strip is coiled. The desired mechanical properties and Metallurgical Structure of the strip are achieved by controlling the cooling rate and temperature of the strip on the ROT. This paper describes a novel online parallel controller which incorporates both feedforward and feedback actions to control the temperature of the strip on the ROT. The performance of the proposed controller has been studied with the aid of a real-time simulator and is reported in this paper.

Pawel Pawlus - One of the best experts on this subject based on the ideXlab platform.

  • effects of Metallurgical Structure and cylinder surface topography on the wear of piston ring cylinder assemblies under artificially increased dustiness conditions
    Wear, 1994
    Co-Authors: Jacek Michalski, Pawel Pawlus
    Abstract:

    Abstract The aim of this work is to determine the effects of Metallurgical Structure and cylinder surface topography on the abrasive wear of piston-piston ring assemblies. The cylinders tested were made of grey cast irons of different Structures. They had also various surface topographies as a result of honing by abrasive tools. These cylinders were tested during automotive gasoline engine operation under artificially increased dusty conditions. Similar investigations were carried out using a tribotest machine. After the engine tests, it is evident that cylinders of pearlitic-ferritic Structure show the best abrasive wear resistance. This result can be explained by the possibility that quartz particles can be embedded in the comparatively big graphite flakes located within a soft ferrite matrix. The effect of the presence of phosphorus eutectic on the wear of piston ring-cylinder assemblies in comparison to the pearlitic Structure is negligible. However, the influence of the surface topography of grey cast iron cylinders on abrasive wear during engine operation under increased dusty conditions is substantial.

Seyyed Ehsan Mirsalehi - One of the best experts on this subject based on the ideXlab platform.

  • transient liquid phase bonding of az31 magnesium alloy Metallurgical Structure and mechanical properties
    Journal of Manufacturing Processes, 2018
    Co-Authors: Sohrab Ghahri Saremi, Seyyed Ehsan Mirsalehi, Ali Shamsipur
    Abstract:

    Abstract In the present paper, AZ31 magnesium alloy was transient liquid phase bonded using aluminum interlayers (with two different thicknesses of 9 and 14 μm), two bonding temperature of 440 and 455 C and different holding times. Optical and scanning electron microscopies were employed to determine the progression of isothermal solidification. In addition, X-ray diffraction method was used to determine the formation of the brittle Al12Mg17 compound. The hardness was found to be higher at the joint center compared to the joint sides, which can be related to the eutectic Structure and high amount of intermetallic compounds at the center. The results showed that the 9 μm-interlayer led to greater shear strength, elongation and failure energy than the 14 μm interlayer, and the highest shear strength of ∼35 MPa was obtained for 75 min bonding time and 9 μm interlayer. The fracture surface evaluation revealed the presence of more plastic deformation for the joints made by the thinner interlayer.

  • investigation on Metallurgical Structure and mechanical properties of dissimilar al 2024 cu fsw t joints
    Transactions of The Indian Institute of Metals, 2017
    Co-Authors: Mostaan Lotfalian Saremi, Seyyed Ehsan Mirsalehi, Ali Shamsipur
    Abstract:

    In this research, T-joining of AA2024-T4 and commercially pure copper were performed successfully using friction stir welding. Effect of welding parameters on Metallurgical and mechanical characteristics of the joints was studied. For this purpose, tensile strength, microhardness, and macro- and microStructures of the joints were investigated. Also, the fracture surfaces were examined using XRD and SEM. The best results were obtained for the 1130 rpm rotation speed (ω) and 12 mm/min travel speed (v), with the UTS of 156 MPa (~70% of Cu strength). The microhardness test showed that TMAZ and base metal of Al side had the maximum hardness amounts (148 and 155 HV, respectively). Generally, increase in the ω2/v ratio caused the nugget zone and HAZ grain size to increase. The results revealed the formation of Al2Cu and Al4Cu9 intermetallic compounds in the border zone of the joints. The fractography results showed the occurrence of cleavage fracture in all the samples.