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Structure, Composition, And Mechanical Properties Of Australian Orthodontic Wires, Brian M. Pelsue, Spiros Zinelis, T. Gerard Bradley, David W. Berzins, Theodore Eliades, George Eliades
Structure, Composition, And Mechanical Properties Of Australian Orthodontic Wires, Brian M. Pelsue, Spiros Zinelis, T. Gerard Bradley, David W. Berzins, Theodore Eliades, George Eliades
T. Gerard Bradley
Objective: To investigate the surface morphology, structure, elemental composition, and key mechanical properties of various sizes and tempers of Australian wires. Materials and Methods: Three types of Australian wire were used: 0.016″ regular, 0.018″ regular+, and 0.018″ special+ (A.J. Wilcock, Whittlesea, Victoria, Australia). Each type of wire was subjected to scanning electron microscopy (SEM) analysis, x-ray energy dispersive spectroscopy (EDS) investigation, Vickers hardness testing, and tensile testing. The modulus of elasticity and ultimate tensile strength were determined. Hardness, modulus, and strength data were analyzed with one-way analysis of variance (ANOVA) and Tukey testing at the .05 level of significance. Results: …
Nanomechanical Characterization Of Cavity Growth And Rupture In Hydrogen-Implanted Single-Crystal Batio3., Young-Bae Park, Patrick Nardi, Xiaodong Li, Harry A. Atwater
Nanomechanical Characterization Of Cavity Growth And Rupture In Hydrogen-Implanted Single-Crystal Batio3., Young-Bae Park, Patrick Nardi, Xiaodong Li, Harry A. Atwater
Xiaodong Li
A thermodynamic model of cavitynucleation and growth in ion-implanted single-crystal BaTiO3 layer is proposed, and cavity formation is related to the measured mechanical properties to better understand hydrogen implantation-induced layer transfer processes for ferroelectric thin films. The critical radius for cavitynucleation was determined experimentally from blistering experiments performed under isochronal anneal conditions and was calculated using continuum mechanical models for deformation and fracture, together with thermodynamic models. Based on thermodynamic modeling, we suggest that cavitiesgrow toward the cracking criteria at a critical blister size whereupon gas is emitted from ruptured cavities. The main driving force for layer splitting is the …
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
George G. Adams
The proper selection of electrical contact materials is one of the critical steps in designing a metal contact microelectromechanical system (MEMS) switch. Ideally, the contact should have both very low contact resistance and high wear resistance. Unfortunately this combination cannot be easily achieved with the contact materials currently used in macroswitches because the available contact force in microswitches is generally insufficient (less than 1 mN) to break through nonconductive surface layers. As a step in the materials selection process, three noble metals, platinum (Pt), rhodium (Rh), ruthenium (Ru), and their alloys with gold (Au) were deposited as thin films on …
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
George G. Adams
A finite element model was developed to study adhesion of elastic-plastic microcontacts in a previous investigation. An interesting result was the identification of two distinct separation modes, i.e. brittle and ductile separation. In the current study, that model is used to conduct a series of simulations to determine the influence of four nondimensional parameters (including the maximum load parameter) on the contact and on the separation modes. The results show that the parameter S (the ratio of the theoretical stress to the hardness) and δƒ/δc (representing the loading level) are the most important. Smaller S can only lead to brittle …
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Nicol E. McGruer
The proper selection of electrical contact materials is one of the critical steps in designing a metal contact microelectromechanical system (MEMS) switch. Ideally, the contact should have both very low contact resistance and high wear resistance. Unfortunately this combination cannot be easily achieved with the contact materials currently used in macroswitches because the available contact force in microswitches is generally insufficient (less than 1 mN) to break through nonconductive surface layers. As a step in the materials selection process, three noble metals, platinum (Pt), rhodium (Rh), ruthenium (Ru), and their alloys with gold (Au) were deposited as thin films on …
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
Nicol E. McGruer
A finite element model was developed to study adhesion of elastic-plastic microcontacts in a previous investigation. An interesting result was the identification of two distinct separation modes, i.e. brittle and ductile separation. In the current study, that model is used to conduct a series of simulations to determine the influence of four nondimensional parameters (including the maximum load parameter) on the contact and on the separation modes. The results show that the parameter S (the ratio of the theoretical stress to the hardness) and δƒ/δc (representing the loading level) are the most important. Smaller S can only lead to brittle …
Structural And Mechanical Properties Of Nanostructured Tio2 Thin Films Deposited By Rf Sputtering
Structural And Mechanical Properties Of Nanostructured Tio2 Thin Films Deposited By Rf Sputtering
A.S. Md Abdul Haseeb
This study mainly aims to evaluate the effects of substrate temperatures on the mechanical properties of TiO2 thin films deposited on glass substrates by radio-frequency (RF) magnetron sputtering. All titania films possess anatase structure having a nodular morphology. AES results reveal that Si and Na ions from glass diffuse into TiO2 films at higher substrate temperatures. Micro-scratch and wear tests were conducted to evaluate their mechanical and tribological properties. The adhesion critical loads of TiO2 films deposited at room temperature, 200 and 300°C are found to be 1.51, 1.54 and 1.08N, respectively. Scratch hardness also increases from 11.5 to 13.6GPa …
On The Nature Of The Electrochemically Synthesized Hard Fe-0.96 Mass Pct C Alloy Film
On The Nature Of The Electrochemically Synthesized Hard Fe-0.96 Mass Pct C Alloy Film
A.S. Md Abdul Haseeb
A hard Fe-0.96 mass pet C alloy with a hardness value of 810 HV has been electrochemically synthesized from a ferrous sulfate bath containing a small amount of citric acid and L-ascorbic acid. The nature of the alloy has been investigated by a number of techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Mössbauer spectroscopy, differential scanning calorimetry (DSC), and magnetic measurements. The decomposition behavior of the alloy is also studied and compared with that of thermally prepared martensite. It has been found that the electrochemically deposited Fe-C alloy exists in …
Study Of The Wear Behaviour Of Al-4.5% Cu-3.4% Fe In Situ Composite: Effect Of Thermal And Mechanical Processing
A.S. Md Abdul Haseeb
Wear behaviour of as-cast and heat-treated spheroidal graphite (SG) cast iron has been studied under dry sliding conditions using a pin-on-disc type apparatus. Wear tests were carried out at a linear sliding speed of 0.88 m s -1, under a constant load of 1.5 kg. All tests were performed in ambient air at room temperature. Extent of wear damage and wear mechanisms were investigated by means of weight loss measurement, optical microscopy, microhardness measurement and X-ray diffractometry on wear debris. The wear rate measured after 9500 m of sliding is found to be about three times higher in the as-cast …