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Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study Dec 2003

Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study

A.S. Md Abdul Haseeb

Three aluminium metal matrix composites containing reinforcing particles of B4C, SiC and Al2O3 (0-20vol.%) were processed. The stir-casting manufacturing route followed by hot extrusion was utilized, being one of the cost-effective industrial methods. A clear interfacial reaction product/layer was found at Al-SiC interface for composites held for a relatively long processing time (>30 min). No reaction product was observed at Al-B4C and Al-Al2O3 interfaces at the resolution limit of the SEM used. On the other hand, two secondary phases (alumina and another phase containing aluminium, boron and carbon) were found in the aluminum matrix away from the interface in ...


Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study Dec 2003

Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study

A.S. Md Abdul Haseeb

Three aluminium metal matrix composites containing reinforcing particles of B4C, SiC and Al2O3 (0-20vol.%) were processed. The stir-casting manufacturing route followed by hot extrusion was utilized, being one of the cost-effective industrial methods. A clear interfacial reaction product/layer was found at Al-SiC interface for composites held for a relatively long processing time (>30 min). No reaction product was observed at Al-B4C and Al-Al2O3 interfaces at the resolution limit of the SEM used. On the other hand, two secondary phases (alumina and another phase containing aluminium, boron and carbon) were found in the aluminum matrix away from the interface in ...


Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study, Haseeb Asma Dec 2003

Microstructure And Interface Characteristics Of B4c, Sic And Al2o3 Reinforced Al Matrix Composites: A Comparative Study, Haseeb Asma

Haseeb ASMA

Three aluminium metal matrix composites containing reinforcing particles of B4C, SiC and Al2O3 (0-20 vol.%) were processed. The stir-casting manufacturing route followed by hot extrusion was utilized, being one of the cost-effective industrial methods. A clear interfacial reaction product/layer was found at Al-SiC interface for composites held for a relatively long processing time (>30 min). No reaction product was observed at Al-B4C and Al-Al2O3 interfaces at the resolution limit of the SEM used. On the other hand, two secondary phases (alumina and another phase containing aluminium, boron and carbon) were found in the aluminum matrix away from the interface ...


Memories Of Dad 15.11.1902- 16.10.1970 A Celebration Of The Life And Works Of Edmund Ramsay Wigan, Marcus R. Wigan Nov 2003

Memories Of Dad 15.11.1902- 16.10.1970 A Celebration Of The Life And Works Of Edmund Ramsay Wigan, Marcus R. Wigan

Marcus R Wigan

Edmund Ramsay Wigan was a distinguished Acoustical and Mechanical Engineer, who patented literally several dozen devices and ideas, was responsible for the field radios used by the Allied forces in Europe in World War 2, and when invited as the special merit Senior Principal at the BBC Research lab in Kingston, Surrey, invented the quality meters, tuned all the BBC broadcasting aerials for quality, and did applied research creating a reliable measure for subjective levels of sound distortion. As a minor practical measure invented the one cycle offset used ever since to avoid feedback in large multi-miked rooms. He was ...


Analysis Of Core Buckling Defects In Sheet Metal Coil Processing, P.M. Lin, Jonathan A. Wickert Nov 2003

Analysis Of Core Buckling Defects In Sheet Metal Coil Processing, P.M. Lin, Jonathan A. Wickert

Jonathan A. Wickert

The elastic stability of a wound coil comprising a central core and many layers of sheet metal is modeled and analyzed. A common failure mode resulting from unfavorable internal stresses—called v-buckling—is characterized by a section of the core buckling inward, possibly with several nearby sheet metal layers. In the present study, the core is modeled as a thin cylinder that is subjected to (i) the uniform external pressure generated by the coil's wound-in stresses and (ii) a nonuniform elastic foundation around its circumference that represents core-coil contact or loss thereof. The model and an iterative numerical technique ...


Vibration Of Flex Circuits In Hard Disk Drives, Jonathan A. Wickert Jul 2003

Vibration Of Flex Circuits In Hard Disk Drives, Jonathan A. Wickert

Jonathan A. Wickert

A flex circuit connects the stationary electronic components in a hard disk drive to the rotating arm that carries the read/write heads and positions them above data tracks on the disk. Flex circuits are conventionally formed as a laminate of polyimide substrate, adhesive, and copper conductors. Deformation of a flex circuit is discussed in the context of the following stages: the initial unstressed shape, configurations in which stresses set and relax in response to elevated temperature, equilibrium, and small amplitude vibration. The model involves displacements of the flex circuit in the directions tangent and normal to the local equilibrium ...


Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data Jun 2003

Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data

A.S. Md Abdul Haseeb

This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected ...


Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data Jun 2003

Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data

A.S. Md Abdul Haseeb

This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected ...


Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data Jun 2003

Wear Failure Of A Leaded Bronze Bearing: Correlation Between Plant Experience And Laboratory Wear Test Data

A.S. Md Abdul Haseeb

This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were subjected ...


Study On The Nature Of The Electrochemically Synthesized Hard Fe-15.4 Mass % Ni-0.70 Mass % C Alloy Film, Haseeb Asma Apr 2003

Study On The Nature Of The Electrochemically Synthesized Hard Fe-15.4 Mass % Ni-0.70 Mass % C Alloy Film, Haseeb Asma

Haseeb ASMA

Electrochemical synthesis of hard Fe-15.4 mass% Ni-0.70 mass% C alloy film with a hardness 750 HV was carried out from sulfate-based bath containing a small amount of citric acid and L-ascorbic acid. The nature of the alloy was investigated by different characterization techniques including x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, Mossbauer spectroscopy, differential scanning calorimetry, and magnetic measurements. The decomposition behavior of the alloy was also studied and compared with that of thermally prepared martensite. It was found that the electrochemically deposited Fe-Ni-C alloy exists in a state that is ahead of the ...


Vortex-Induced Flame Extinction In Two-Phase Counterflow Diffusion Flames With Ch Planar Laser-Induced Fluorescence And Particle-Image Velocimetry, Alix Lemaire, Terrence R. Meyer, Katharina Zahringer, Juan C. Rolon, James R. Gord Mar 2003

Vortex-Induced Flame Extinction In Two-Phase Counterflow Diffusion Flames With Ch Planar Laser-Induced Fluorescence And Particle-Image Velocimetry, Alix Lemaire, Terrence R. Meyer, Katharina Zahringer, Juan C. Rolon, James R. Gord

Terrence R Meyer

Here the interaction between a laminar two-phase, non-pre-mixed counterflow flame and a vortex is examined. Special emphasis is given to the influence of different flame and vortex parameters on the extinction behavior of the flame. Simultaneaous planar laser-induced fluorescence of the CH radical layer produced by the flame and particle-image velocimetry measurements of the flowfield are used to characterize the flame–vortex interaction. These simultaneous diagnostics are used for the first time in this configuration. The extinction processes occurring during the flame–vortex interaction can be analyzed by this method, especially the influence of strain at the flame surface. The ...


Development Of A Fan Airflow Station For Airflow Control In Vav Systems, David Yuill, Nathan Redmann, Mingsheng Liu Feb 2003

Development Of A Fan Airflow Station For Airflow Control In Vav Systems, David Yuill, Nathan Redmann, Mingsheng Liu

David Yuill

A fan airflow station has been developed by the authors. This station is used to determine fan airflow using fan speed and fan head as inputs. These inputs can be measured accurately in variable air volume (VAV) systems, so they can be used as a cost-effective control monitoring method for heating, ventilation and air conditioning (HVAC) systems. Theoretical models have been developed for the flow station using both second and third order relationships between the airflow and the inputs. The theoretical model has been experimentally tested and excellent agreement between the model and the experimental values was found. The second ...


Fretting Wear Of Metallic Multilayer Films Jan 2003

Fretting Wear Of Metallic Multilayer Films

A.S. Md Abdul Haseeb

Fretting wear behaviour of electrodeposited Cu/Ni multilayer films with 10 and 5 nm thick sublayers has been investigated against a hardened steel ball as the counter body and compared with that of the constituents, Cu and Ni. The wear tests were carried out by using a ball-on-flat geometry at a translation frequency of 8 Hz and slip amplitude of 100 μm. Friction force was recorded on line during the tests. At the end of the tests, the wear scars were examined by laser surface profilometry, scanning electron microscopy and energy dispersive X-ray microanalysis. It has been observed that the ...


Three-Dimensional Landau Theory For Multivariant Stress-Induced Martensitic Phase Transformations. Iii. Alternative Potentials, Critical Nuclei, Kink Solutions, And Dislocation Theory, Valery I. Levitas, Dean L. Preston, Dong Wook Lee Jan 2003

Three-Dimensional Landau Theory For Multivariant Stress-Induced Martensitic Phase Transformations. Iii. Alternative Potentials, Critical Nuclei, Kink Solutions, And Dislocation Theory, Valery I. Levitas, Dean L. Preston, Dong Wook Lee

Valery I. Levitas

In part III of this paper, alternative Landau potentials for the description of stress-and temperature-induced martensitic phase transformations under arbitrary three-dimensional loading are obtained. These alternative potentials include a sixth-degree (2-4-6) polynomial in Cartesian order parameters and a potential in hyperspherical order parameters. Each satisfies all conditions for the correct description of experiments. The unique features of the potentials are pointed out and a detailed comparison of the potentials is made for NiAl alloy. Analytic solutions of the one-dimensional time-independent Ginzburg-Landau equations for the 2-3-4 and 2-4-6 potentials for a constant-stress tensor and invariant-plane strain are obtained and compared. Solutions ...