Mathematical Modeling of Friction Plug Welding with Preheating Effect

2014 ◽  
Vol 984-985 ◽  
pp. 600-603 ◽  
Author(s):  
N. Rajesh Jesudoss Hynes ◽  
P. Nagaraj ◽  
P. Thanga Kumar
Keyword(s):  
Temperature Profile ◽  
Analytical Modeling ◽  
Heating Temperature ◽  
Dissimilar Materials ◽  
Work Piece ◽  
External Heat Source ◽  
Friction Plug Welding ◽  
Recent Variation ◽  
Intermediate Surface ◽  
Land Width

Friction plug welding, a recent variation of friction welding is a process of joining of two similar or dissimilar materials. The joint efficiency can be enhanced by applying external heat source or pre-heating at the work piece surfaces. Heat flux generation at intermediate surface is computed due to friction between the materials considering the co-efficient of friction. The land width is varied by varying the diameter of the plug to find its effect on the temperature profile. Analytical modeling is carried out with and without the effect of pre-heating. Temperature distribution in the work piece was calculated for different plug diameter with different values of pre-heating temperature ranging from 300oC-600oC. It is observed that while decreasing the land width there is a linear fall in temperature profile. With preheating, higher peak temperature is achieved at less friction time. High quality weld could be achieved with less processing time.

Identification of Optimum Heating Temperature in Thermal Assisted Turning of Stainless Steel Using Three Different Approaches

2013 ◽  
Vol 393 ◽  
pp. 194-199 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
Muammer Din Arif ◽  
Noor Hawa B. Mohamad Rasdi ◽  
Khairus Syakirah B. Mahmud ◽  
Abdul Hakam B. Ibrahim ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Heating Temperature ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
304 Stainless Steel ◽  
Depth Of Cut ◽  
Work Piece ◽  
Optimum Temperature ◽  
Main Concept

Thermal or heat assisted machining is used to machine hard and difficult-to-machine materials such as Inconel and Titanium alloys. The main concept is that localized surface heating of the work-piece reduces the yield strength of the material significantly, making it amenable to plastic deformation and machining. Thus, heat assisted machining has been used for over a century. However, the heating technique and temperature are very much dependent on the type of working material. Therefore, a multitude of heating techniques has been applied over the years including Laser Assisted Machining (LAM) and Plasma Enhanced Machining (PEM) in the industry. But such processes are very expensive and have not been found in wide scale applications. The authors of the current research have therefore looked into the application of a simple Tungsten Inert Gas (TIG) welding setup to perform heat assisted turning of AISI 304 Stainless Steel. Such welding equipment is relatively cheap and available. Also, stainless steel is perennially used in the industry for high strength applications. Hence, it is very important to determine with optimal cutting temperature when applying a TIG setup for heat assisted machining of stainless steel. This paper describes three separate techniques for determining the optimum temperature. All three processes applied the same experimental setup but used different variables for evaluating the best temperature. The first process used vibration amplitude reduction with increment in temperature to identify the desired temperature. The second process used chip shrinkage coefficient to locate the same temperature. And finally, the third process investigated tool wear as a criterion for determining the optimum temperature. In all three cases the three primary cutting parameters: cutting speed, feed, and depth of cut, were varied in the same pattern. The results obtained from all three approaches showed that 450oC was undoubtedly the best temperature for heat assisted machining of stainless steel.

Clamp Load Decay in Preloaded Dissimilar Lightweight-Material Joints due to Cyclic Temperature

2014 ◽  
Author(s):  
Sayed A. Nassar ◽  
Amir Kazemi ◽  
Mohamad Dyab
Keyword(s):  
Finite Element ◽  
Temperature Profile ◽  
Thermal Loading ◽  
Dissimilar Materials ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Temperature Load ◽  
Cyclic Temperature ◽  
Material Creep ◽  
Aluminum And Magnesium Alloys

Experimental and Finite Element methods are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of dissimilar-materials. Joint material combinations include steel and lightweight materials such as aluminum and magnesium alloys, with various different thicknesses. The range of cyclic temperature profile varies between −20°C and +150°C. A computer-controlled environmental chamber is used for generating the desired cyclic temperature profile and duration. Real time clamp load data is collected using high-temperature load cells. Percent clamp load decay is investigated for various combinations of joint materials, initial preload level, and test specimen thicknesses. Thermal and material creep finite element analysis is performed using temperature-dependent mechanical properties. FEA result has provided insight into interesting experimental observations regarding model predictions and the experimental data is discussed.

Thermal Modeling of Direct Digital Melt-Deposition Processes

2010 ◽  
Vol 654-656 ◽  
pp. 1540-1544 ◽  
Author(s):  
Khershed P. Cooper ◽  
Samuel G. Lambrakos
Keyword(s):  
Tool Path ◽  
Complex Geometry ◽  
Dissimilar Materials ◽  
Functionally Graded ◽  
Heat Diffusion ◽  
Work Piece ◽  
Layer By Layer ◽  
Multiple Materials ◽  
Deposition Processes ◽  
Melt Deposition

Additive manufacturing involves creating three-dimensional objects by depositing materials layer-by-layer. The freeform nature of the method permits the production of components with complex geometry. Deposition processes provide one more capability, which is the addition of multiple materials in a discrete manner to create “heterogeneous” objects with locally controlled composition. The result is direct digital manufacturing (DDM) by which dissimilar materials are added voxel-by-voxel (a voxel is volumetric pixel) following a predetermined tool-path. A typical example is functionally-graded material such as a gear with a tough core and a wear resistant surface. The inherent complexity of DDM processes is such that process modeling based on direct physics-based theory is difficult, especially due to a lack of temperature-dependent thermo-physical properties and particularly when dealing with melt-deposition processes. To overcome this difficulty the inverse problem approach is adopted to develop thermal models for multi-material, direct digital melt-deposition. This approach is based on the construction of a numerical-algorithmic framework for modeling anisotropic diffusivity such as that which would occur during energy deposition within a heterogeneous work-piece. This framework consists of path-weighted integral formulations of heat diffusion according to spatial variations in material composition and requires consideration of parameter sensitivity issues.

Friction Stir Welding of Dissimilar AA 2024-T3 to AZ31B-H24 Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 3661-3666 ◽  
Author(s):  
Xin Jin Cao ◽  
Mohammad Jahazi
Keyword(s):  
Friction Stir Welding ◽  
Dissimilar Materials ◽  
Work Piece ◽  
Butt Joints ◽  
Friction Stir ◽  
Tilting Angle ◽  
Aa 2024 ◽  
First Time ◽  
Solid State Joining

As a relatively new solid-state joining process, friction stir welding (FSW) may provide a feasible approach to join dissimilar materials such as Mg to Al alloys. In this work, the effects of selected process parameters including work-piece placement, pin tilting angle, and pin location on the quality of dissimilar AA 2024-T3 to AZ31B-H24 butt joints were investigated for the first time. Sound butt joints with low distortion and no solidification cavities or cracks were successfully obtained indicating the potential of FSW to join dissimilar Al to Mg alloys.

A Study on Vacuum Brazing Procedure of Plate Heat Exchanger

2004 ◽  
Vol 471-472 ◽  
pp. 640-643
Author(s):  
Sheng Sheng Zhang ◽  
Y.H. Cheng ◽  
L. Cheng
Keyword(s):  
Heat Exchanger ◽  
Heating Temperature ◽  
Plate Heat Exchanger ◽  
Work Piece ◽  
Processing Property ◽  
Corrosion Resistant ◽  
Plate Heat ◽  
Vacuum Brazing ◽  
Joint Structure

The effects of work-piece heating temperature, holding time, and vacuity upon the quality of soldered fittings, when welding stainless heat exchanger (0cr17Ni12Mo2 plate) by vacuum brazing, are discussed in this paper. It also presents an optimized brazing procedure of welding heat exchanger. The processing property of soldered corrosion-resistant plate handled by the brazing procedure are discussed and optimized. Based on the analysis of samples taken from different sections of the welding seams, the paper studies the joint structure of brazing stainless steel.

scholarly journals Magnetic Pulse Welding Technology

2011 ◽  
Vol 7 (2) ◽  
pp. 169-179
Author(s):  
Ahmad Jassim
Keyword(s):  
Mechanical Energy ◽  
Dissimilar Materials ◽  
Electrical Energy ◽  
Work Piece ◽  
Magnetic Pulse ◽  
Metallic Materials ◽  
Welding Technology ◽  
Conventional Machine ◽  
Pulse Welding ◽  
Pulse Technology

In this paper, the benefits of using Magnetic Pulse machine which is belong to Non-conventional machine instead of conventional machine. Magnetic Pulse Technology is used for joining dissimilar metals, and for forming and cutting metals. It is a non contact technique. Magnetic field is used to generate impact magnetic pressure for welding and forming the work piece by converted the electrical energy to mechanical energy. It is enable us to design previously not possible by welding dissimilar materials and allowing to welds light and stronger materials together. It can be used to weld metallic with non metallic materials to created mechanical lock on ceramics, polymers, rubbers and composites. It is green process; there is no heat, no radiation, no gas, no smoke and sparks, therefore the emissions are negligible.

Analytical and High-Resolution EM Study of Crystalline Phases formed at Metal-Ceramic Interface

1990 ◽  
Vol 48 (2) ◽  
pp. 426-427
Author(s):  
N. Merk ◽  
A. P. Tomsia ◽  
G. Thomas
Keyword(s):  
Cross Section ◽  
Dissimilar Materials ◽  
Ceramic Materials ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Structural Applications ◽  
Metal Ceramic ◽  
The Subject ◽  
Ceramic Compounds ◽  
Scanning Electron

A recent development of new ceramic materials for structural applications involves the joining of ceramic compounds to metals. Due to the wetting problem, an interlayer material (brazing alloy) is generally used to achieve the bonding. The nature of the interfaces between such dissimilar materials is the subject of intensive studies and is of utmost importance to obtain a controlled microstructure at the discontinuities to satisfy the demanding properties for engineering applications . The brazing alloy is generally ductile and hence, does not readily fracture. It must also wett the ceramic with similar thermal expansion coefficient to avoid large stresses at joints. In the present work we study mullite-molybdenum composites using a brazing alloy for the weldment.A scanning electron micrograph from the cross section of the joining sequence studied here is presented in Fig. 1.

Interfacial structures of dissimilar materials joined by capacitor-discharge welding

1994 ◽  
Vol 52 ◽  
pp. 534-535
Author(s):  
C. P. Doğan ◽  
R. D. Wilson ◽  
J. A. Hawk
Keyword(s):  
Rapid Solidification ◽  
Fusion Zone ◽  
Dissimilar Materials ◽  
Solidification Process ◽  
Weld Interface ◽  
Capacitor Discharge ◽  
Fine Grained ◽  
Iron Aluminum ◽  
Conductive Ceramics ◽  
Capacitor Discharge Welding

Capacitor Discharge Welding is a rapid solidification technique for joining conductive materials that results in a narrow fusion zone and almost no heat affected zone. As a result, the microstructures and properties of the bulk materials are essentially continuous across the weld interface. During the joining process, one of the materials to be joined acts as the anode and the other acts as the cathode. The anode and cathode are brought together with a concomitant discharge of a capacitor bank, creating an arc which melts the materials at the joining surfaces and welds them together (Fig. 1). As the electrodes impact, the arc is extinguished, and the molten interface cools at rates that can exceed 106 K/s. This process results in reduced porosity in the fusion zone, a fine-grained weldment, and a reduced tendency for hot cracking.At the U.S. Bureau of Mines, we are currently examining the possibilities of using capacitor discharge welding to join dissimilar metals, metals to intermetallics, and metals to conductive ceramics. In this particular study, we will examine the microstructural characteristics of iron-aluminum welds in detail, focussing our attention primarily on interfaces produced during the rapid solidification process.

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