فهرست مطالب

Journal of Modern Processes in Manufacturing and Production
Volume:4 Issue: 4, Autumn 2015

  • تاریخ انتشار: 1394/10/30
  • تعداد عناوین: 6
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  • Hassan Gheisari*, Ebrahim Karamian, Mohammad Barati Pages 5-14
    The output error of the globoidal cam mechanism can be considered as a relevant indicator of mechanism performance, because it determines kinematic and dynamical behavior of mechanical transmission. Based on the differential geometry and the rigid body transformations, the mathematical model of surface geometry of the globoidal cam is established. Then we present the analytical expression of the output error (including the transmission error and the displacement error along the output axis) by considering different manufacture and assembly errors. The effects of the center distance error, the perpendicular error between input and output axes and the rotational angle error of the globoidal cam on the output error are systematically analyzed. A globoidal cam mechanism which is widely used in automatic tool changer of CNC machines is applied for illustration. Our results show that the perpendicular error and the rotational angle error have little effects on the transmission error but have great effects on the displacement error along the output axis. This study plays an important role in the design, manufacture and assembly of the globoidal cam mechanism.
    Keywords: Globoidal cam mechanism, Manufacture error, Transmission error, Automatic tool changer
  • Javad Shahbazi Karami *, Gholamhasan Payganeh, Hamid Rakhodaei Pages 15-28
    This paper presents a control model of the hydroforming and the dual hydroforming process of a tube. The theoretical part includes calculations to measure the change in tube thickness through the developed process. The hydroforming and the dual hydroforming processes are simulated in the SOLIDSIMULATION software and the static and the dynamic simulations are modeled. The obtained results for the T-shape and the X-shape dies are compared and investigated. Moreover, the developed software in MATLAB calculates the process parameters. The inputs of the developed software are the maximum internal pressure and the axial feed that could be adjusted with linear and non-linear functions. Furthermore, the material of the tube, as well as the tube’s parameters, such as length, thickness, and radius, must to be given to the software. However, the properties of the tube could automatically support the CAD model. The software-generated results are the applied stress, displacement, and the energy through the process. This paper deals with the control strategy model developed in thesoftware packages. The obtained results are then subsequently compared with those of several experiments.
    Keywords: Tube Hydroforming, Computer Aided Design, Dual Hydroforming
  • Mohammad Honarpisheh*, Mohammad Reza Aghili, Mahdi Kotobi Pages 29-38
    Equal channel angular rolling (ECAR) process is one of the methods that have been used to make ultra-fine materials by imposing severe plastic deformation. After repeating the process several times, a large effective strain is applied to the sample that can cause decreasing the grain size and improving the mechanical and physical properties of the metal. In this study, thermal conductivity of the samples that were produced by ECARwas investigated experimentally. Accordingly, the strips of aluminum alloy 3003 were ECARed up to 10 passes through route-A and route C. The effect of number of ECAR pass and routes of ECAR process (A and C) were investigated. Furthermore, tensile behavior and micro-hardness of ECARed samples werestudied.According to the results,the thermal conductivity of samples increased up to definite pass and raised to its maximum value, then had an oscillatory trend up to tenth pass. Although this improvement of the thermal conductivitywasn’t significantly, but the improvement of yield and ultimate strength and micro-hardness of the samples in passes associated with the maximum thermal conductivity, were meaningfully and so,this ECARed alloys can be used in harder situation.
    Keywords: Severe plastic deformation, Equal channel angular rolling, Thermal Conductivity, Aluminum alloy 3003
  • Sayed Ali Mousavi Pages 39-45
    Non-Destructive Testing & Evaluation methods are developed to inspect and investigate materials and structures. Ultrasonic Testing is an NDT method can be used for measuring the thickness of objects, as one of its significant applications. The objective of this paper is designing and applying an intelligent UT fuzzy control system for evaluating the thickness of thin metal objects in a range of 5-20 mm. The designed Fuzzy Logic Controller has five variables including four inputsand one output. The inputs are frequency of probe, couplant's acoustic impedance, object’s acoustic impedance, and temperature; also the output is thickness, particularly of thin objects. This suggested method has been applied to four metals. Our strategy consists of three steps; and it has been preferred to utilize pulse-echo method because of using the immersion method. The experimental results imply that the proposed procedure has been able to control and measure the thickness of thin objects (5-20 mm) successfully within a rate of mean error of 0.5%.
    Keywords: Non, Destructive, Fuzzy logic, Thin, Control
  • Mohammad Hossein Shahsavari, Farshid Ahmadi* Pages 47-58
    Among different SPD techniques, Equal channel Angular Pressing has attracted the most attentions, because of applying large strain to solid bulk materials. In this research, ECAP process up to 6 passes was carried out on a pure copper and a 6012 Al-Mg-Si alloy with BC route in ECAP dies with Φ=120 and Ψ=20 and diameter of 20and 10 millimeter respectively. Moreover, X ray diffraction (XRD) system was utilized to investigate changes of the crystallite size and texture variations using for calculating texture parameters and comparing the X-ray diffraction patterns of annealed samples and Ecaped samples. Dominant texture of (111) in annealed aluminum altered to a mixture plane. Also, dominant texture of annealed copper of (111) and (200) shifted to anotherplane. The opposite of copper samples, changes in diameter and length of aluminum specimens had no effect on diffraction pattern of them. The microstructures were evaluated by OM. The results showed that grain size of annealed aluminum after six passes of ECAP decreased by 75%.
    Keywords: Aluminum Alloy 6012, Pure Copper, SPD, Equal Channel Angular Pressing, Texture
  • Nahid Hassanzadeh Nemati, Shiva Yasini*, Maryam Aryana Pages 59-65
    Different methods have been evaluated for manufacturing the porous Ti6Al4V alloys according to decreasing stress shielding phenomenon and increasing mechanical compatibility between the metallic components and the host tissue. For this purpose, in this work Ti6Al4V alloy chips were pressed under 400 MPa pressure and then samples were categorized and heated into two groups at 1000 and 1150℃ under a vacuum about 10-4 mbar. The results implied a porosity about 35%, significant reduction of density in prepared segments comparing to bulk ones and a, reduction in the elasticity modulus and better matching with the host cancellous bone tissue. According to the results one can expect to manufacture porous Ti6Al4Vorthopaedic and dental implants using the discussed method.
    Keywords: Hard Tissue Replacement, Ti6Al4V, Chips of Alloy, Orthopaedic Implant