scholarly journals Challenges in the Forging of Steel-Aluminum Bearing Bushings

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 803
Author(s):  
Bernd-Arno Behrens ◽  
Johanna Uhe ◽  
Tom Petersen ◽  
Christian Klose ◽  
Susanne E. Thürer ◽  
...  
Keyword(s):  
Intermetallic Layer ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Internal Diameter ◽  
External Diameter ◽  
Forming Process ◽  
High Deformation ◽  
Eds Analysis ◽  
Steel Aisi ◽  
Metallurgical Bond

The current study introduces a method for manufacturing steel–aluminum bearing bushings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing FexAly phase in the resulting intermetallic layer.

scholarly journals Joining of SiO2 glass and 316L stainless steel using Bi–Ag-based active solders

2020 ◽  
Vol 56 (4) ◽  
pp. 3444-3454
Author(s):  
Felix Weber ◽  
Markus Rettenmayr
Keyword(s):  
Stainless Steel ◽  
Cross Sections ◽  
316L Stainless Steel ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Reaction Products ◽  
Cast State ◽  
Metallic Component ◽  
X Ray ◽  
Solder Interface

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.

Formation and Structure of Work Material in the Friction Stir Forming Process

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Sladjan Lazarevic ◽  
Kenneth A. Ogata ◽  
Scott F. Miller ◽  
Grant H. Kruger ◽  
Blair E. Carlson
Keyword(s):  
Steel Sheet ◽  
Dissimilar Materials ◽  
Mechanical Interlocking ◽  
Forming Process ◽  
Friction Stir ◽  
Joint Structure ◽  
Work Material ◽  
Formation Zone ◽  
Significant Process ◽  
Geometrical Effects

Friction stir forming (FSF) is a new environmentally friendly manufacturing process for lap joining of dissimilar materials. Fundamentally, this process is based on frictionally heating and mechanically stirring work material of the top piece in a plasticized state to form a mechanical interlocking joint within the bottom material. In this research, the significant process parameters were identified and optimized for Al 6014 alloy and mild steel using a design of experiments (DOE) methodology. The overall joint structure and grain microstructure were mapped as the FSF process progressed and the aluminum work material deformed through different stages. It was found that the work material within the joint exhibited two layers, thermomechanical affected zone, which formed due to the contact pressure and angular momentum of the tool, and heat affected formation zone, which was composed of work material formed through the hole in the steel sheet and into the anvil cavity. Two different geometries of anvil design were employed to investigate geometrical effects during FSF of the aluminum. It was found that the direction and amount of work material deformation under the tool varies from the center to the shoulder.

Numerical Study of the Flow Forming Process of AISI 630 Stainless Steel

2011 ◽  
Vol 264-265 ◽  
pp. 24-29 ◽  
Author(s):  
Seyed Mohammad Ebrahimi ◽  
Seyed Ali Asghar Akbari Mousavi ◽  
Mostafa Soltan Bayazidi ◽  
Mohammad Mastoori
Keyword(s):  
Feeding Rate ◽  
Surface Defects ◽  
Numerical Study ◽  
Internal Diameter ◽  
The Finite Element Method ◽  
Forming Process ◽  
Flow Forming ◽  
Cold Forming ◽  
External Variables ◽  
Experimental Process

Flow forming is one of the cold forming process which is used for hollow symmetrical shapes. In this paper, the forward flow forming process is simulated using the finite element method and its results are compared with the experimental process. The variation of thickness of the sample is examined by the ultrasonic tests for the five locations of the tubes. To simulate the process, the ABAQUS explicit is used. The effects of flow forming variables such as the angle of rollers and rate of feeding of rollers, on the external variables such as internal diameter, thickness of tube and roller forces are considered. The study showed that the roller force and surface defects were reduced with low feeding rate and low rollers attack angles. Moreover, the sample internal diameter increased at low feeding rate and low rollers attack angles. The optimum variables for flow forming process were also obtained.

Design and Construction of Cervix Phantom for Brachytherapy Dose Assessment Procedure for Clinical Application

2017 ◽  
pp. 106-109
Author(s):  
Justice Avevor ◽  
Issahaku Shirazu ◽  
Samuel Nii Adu Tagoe ◽  
J. H. Amuasi ◽  
J. J. Fletcher
Keyword(s):  
Clinical Application ◽  
Excellent Result ◽  
Dose Assessment ◽  
Internal Diameter ◽  
Cylindrical Shape ◽  
Assessment Procedure ◽  
External Diameter ◽  
Actual Patient ◽  
Average Patient ◽  
Patient Size

An important point to consider in a brachytherapy dosimetry study is the design of an appropriate phantom size in calculations or experimental measurements. Perspex sheets of various size and thickness are used to design the cervix phantom. The aim of the study is to design and construct cervix phantom to mimic the pelvic segment of a standard adult human patients undergoing Brachytherapy. This is to allow assessment of dose to cervix and the surrounding tissues during cervix Brachytherapy. The methodology include; first phantom design where physical dimensions of the phantom were determined from a sampling of 30 patients’ cases to simulate an average patient size. Secondly, construction of phantom with fabricated cylindrical shape, composed of 6 mm Perspex sheets, and the assembly enclosed with the 4 mm Perspex sheet. The result of the constructed phantom had lateral separation of 34 cm, an anterior and posterior separation of 27 cm; with length of 33 cm. The Perspex pieces were glued to each other with Trichloromethane (chloroform) at room temperature. Chloroform dissolves the Perspex (PMMA), and when applied to the surfaces of the Perspex sheets, the surfaces stick together after the chloroform dries up. In forming the surface of the phantom, the 4 mm Perspex sheet was oven heated to a temperature of 140?C to make the sheet malleable. One end of the phantom was made thicker than the other end by gluing another 6 mm Perspex sheet such that the thickness of that particular end of the phantom was 12 mm. A hole of diameter 6.5 cm, which was a little bit posterior to the phantom, was created central to the 12 mm end of the phantom. The opening created was covered by 11 x 11 cm2 and 12 mm Perspex slab which was formed by gluing two 6 mm sheets together. A hole of diameter 5 cm was also made central to the cover created, such that the centre of this hole matches that of the hole on the end of the phantom. A 2.4 cm thick ring with internal diameter of 5 cm and external diameter of 6 cm was fabricated from 2.4 cm Perspex slab, which was formed from gluing four pieces of 6 mm Perspex sheets together. The fabricated ring was mounted on the 11 x 11 cm2 cover created such that the internal walls of the ring and that of the hole in the cover matches. The ring was then glued to the cover using the chloroform. The built phantom simulate actual patient anatomy and produce an excellent result to be use for clinical application.

scholarly journals Instruments and Methods High Pressure Coupling for Pipe in Deep Water Filled Bore Holes

1963 ◽  
Vol 4 (36) ◽  
pp. 809-812
Author(s):  
R. L. Shreve
Keyword(s):  
High Pressure ◽  
Water Pressure ◽  
The Other ◽  
Internal Diameter ◽  
External Diameter ◽  
Synthetic Rubber ◽  
External Water Pressure ◽  
External Water ◽  
One Year ◽  
Aluminum Pipe

AbstractIn August 1961 an aluminum pipe (3.5 cm. internal diameter, 4.2 cm. external diameter) having 92 specially modified socket couplings (5.0 cm. external diameter) sealed with a quick-polymerizing synthetic rubber was sunk 226 m. in a vertical water-filled bore hole in Blue Glacier, Washington. U.S.A. The geometry of threads and mating surfaces of pipe and coupling was designed to cause increasing external water pressure to tighten the seal. One joint at a depth of 66 m. immediately developed an extremely slow leak (probably because of faulty cleaning), but the other 91 joints apparently were sound, as the pipe was free of water to a depth of at least 157 m. when resurveyed after one year.

Springback Analysis in Bilayer Material Bending

2017 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Fuel Consumption ◽  
Elastic Recovery ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
Thick Layer ◽  
High Strength ◽  
Geometric Error ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Geometric Defect

Exponential increase in the use of auto vehicles, and thus the fuel consumption, which relates to the air pollution, vehicle industry are in a strict environmental regulation from government. Due to which the innovation related to light-weighting is not only an option anymore but became a mandatory necessity to decrease the fuel consumption. To achieve this target, industry has been looking in fabricating components from high strength to ultra-high strength steels. With the usage of these material the lightweight was achieved by reducing a gage thickness. However due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from elastic recovery of a material, which is also known as a springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part, which would not be able to fit in the assembly without secondary operation or compensation in the forming process. Due to these many challenges, other research route involved is composite material, where light materials can be used with high strength material to reduce the overall vehicle weight. This generally includes, tailor welded blanks, multi-layer material, mechanical joining of dissimilar material, etc. Due to the substantial use of dissimilar materials, these parts are also called as hybrid components. It was noted that the part weight decreases with the use of hybrid components without compromising the integrity and safety. In this paper, a springback analysis was performed considering bilayer metal. For this two dissimilar materials aluminum and composite was considered as bonded material. This material was then bent in a channel forming set-up. The bilayer springback was compared in different condition like aluminum layer on punch side and then on die side. These results were then compared with the baseline springback of only aluminum thin and thick layer. It was found that the layer, which sees the punch side, matters due to the differences in elastic properties for both material and thus it directly influences the springback.

Experimental Investigations on Explosive Cladding of Cp-Titanium / AISI 304 Stainless Steel

2008 ◽  
Vol 580-582 ◽  
pp. 629-632 ◽  
Author(s):  
Pezhman Farhadi Sartangi ◽  
Seiyed Ali Asghar Akbari Mousavi
Keyword(s):  
Intermetallic Layer ◽  
Dissimilar Materials ◽  
Composite Plates ◽  
304 Stainless Steel ◽  
Experimental Investigations ◽  
Aisi 304 ◽  
Explosive Cladding ◽  
Metallic Bond ◽  
Wavy Interface ◽  
Weldability Window

The purpose of this study is to produce composite plates by explosive cladding process. This is a process in which the controlled energy of explosives is used to create a metallic bond between two similar or dissimilar materials. The welding conditions were tailored through parallel geometry route by using different explosive ratios to produce both wavy and straight interfaces. In this investigation, a two-pronged study was adopted to establish the conditions required for producing successful solid state welding: (a) Analytical calculations to determine the weldability window; (b) Metallurgical investigations of experiments carried out under different conditions. The required parameters in the experiments were selected through numerical simulations. The analytical calculations confirm the experimental results. Optical microscopy studies show that a transition from a smooth to wavy interface occurs with increase in explosive ratio. Scanning electron microscopy studies show the formation of intermetallic layer in the interface.

scholarly journals XIX.—Preliminary Note on the Compressibility of Glass

1880 ◽  
Vol 29 (2) ◽  
pp. 589-598
Author(s):  
J. Y. Buchanan
Keyword(s):  
Pressure Gauge ◽  
Steel Tube ◽  
Internal Diameter ◽  
Hydraulic Pressure ◽  
External Diameter ◽  
Preliminary Note ◽  
Actual Observation ◽  
Peculiar Form ◽  
Glass Tubes ◽  
The One

The following experiments were undertaken with a view to determine by actual observation the effect produced on solids by hydraulic pressure.The instrument was constructed according to my directions by Mr Milne of Milton House, about two years ago, but it is only now that I have been able to devote myself to its application to the purposes for which it was designed. It consists of a hydraulic pump, which communicates with a steel receiver capable of holding instruments of considerable size, and also with a second receiver of peculiar form. This receiver consists essentially of a steel tube, terminated at each end by thick glass tubes fitted tightly. It is tapped at the centre with two holes, the one to establish connection with the pump, and the other to admit a pressure gauge or manometer. The steel tube may be of any length, being limited only by the extent of laboratory accommodation at disposal. The tube which I am using at present has a length of a little over six feet, and an internal diameter of about three-tenths of an inch. The solid to be experimented on must be in the form of a rod or wire, and must, at the ends at least, be sufficiently small to be able to enter the terminal glass tubes, which have a bore of 0·08″ and an external diameter of 0·42″. The length of the solid is such that when it rests in the steel tube its ends are visible in the glass terminations.

scholarly journals 4. On the Compressibility of Glass

1880 ◽  
Vol 10 ◽  
pp. 697-698 ◽  
Author(s):  
J. Y. Buchanan
Keyword(s):  
Pressure Gauge ◽  
Steel Tube ◽  
Internal Diameter ◽  
Hydraulic Pressure ◽  
External Diameter ◽  
Hydraulic Pump ◽  
Actual Observation ◽  
Peculiar Form ◽  
Glass Tubes ◽  
The One

AbstractThe experiments related in this paper were undertaken with a view to determine, by actual observation, the effect produced on solids by hydraulic pressure. The instrument used consists of a hydraulic pump, which communicates with a steel receiver capable of holding instruments of considerable size, and also with a second receiver of peculiar form. This receiver consists essentially of a steel tube terminated at each end by thick glass tubes fitted tightly. It is tapped at the centre with two holes, the one to establish connection with the pump and the other to admit a pressure-gauge or manometer. The steel tube may be of any length, being limited only by the extent of laboratory accommodation at disposal. The tube which I am using at present has a length of a little over six feet and an internal diameter of about three-tenths of an inch. The solid to be experimented on must be in the form of rod or wire, and must, at the ends, at least, be sufficiently small to be able to enter the terminal glass tubes, which have a bore of 0·08 inch, and an external diameter of 0·42 inch. The length of the rod or wire is such that, when it rests in the steel tube, its ends are visible in the glass terminations.

Mechanics of large and small cerebral arteries in chronic hypertension

1994 ◽  
Vol 266 (3) ◽  
pp. H1027-H1033 ◽  
Author(s):  
M. A. Hajdu ◽  
G. L. Baumbach
Keyword(s):  
Cerebral Artery ◽  
Posterior Cerebral Artery ◽  
Cerebral Arteries ◽  
Internal Diameter ◽  
Chronic Hypertension ◽  
External Diameter ◽  
Cross Sectional ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

The goal of this study was to investigate factors that contribute to reductions in internal diameter of large and small cerebral arteries during chronic hypertension. We measured diameter of second- and third-order branches of the posterior cerebral artery in vitro during maximal dilation with EDTA in 6-mo-old stroke-prone spontaneously hypertensive rats (SHRSP, n = 7) and Wistar-Kyoto rats (WKY, n = 7). Cross-sectional area of the vessel wall, measured histologically, was not significantly different at 70 mmHg in SHRSP and WKY in large or small branches of posterior cerebral artery. In large branches of posterior cerebral artery, external and internal diameters were significantly less at 70 mmHg in SHRSP than in WKY, whereas external and internal diameters converged at 0 mmHg in the two groups of rats. In small branches, on the other hand, external and internal diameters were significantly less at all levels of intravascular pressure in SHRSP than in WKY. The stress-strain relation in posterior cerebral artery of SHRSP was shifted to the left in large branches and to the right in small branches, which indicates that distensibility was reduced in large cerebral arteries of SHRSP and increased in small cerebral arteries. These findings suggest that different mechanisms are responsible for impairment of maximal dilator capacity in large and small cerebral arteries of SHRSP: reduced distensibility in large arteries and remodeling with reduced external diameter in small arteries. Furthermore the findings provide additional support for the concept that hypertrophy may not be a primary factor in impaired maximal dilation.

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