Engineering Commons^™

Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara

Journal of Metals, Materials and Minerals

Hypoeutectic 26 wt% Cr cast irons without and with Mo were prepared in order to investigate their abrasion wear resistance. The annealed specimens were hardened from 1323 K (As-H) and then tempered at three levels of temperatures between 673 and 823 K for 7.2ks, the temperature giving the maximum hardness (HTmax), lower temperature than that at HTmax (L-HTmax ) and higher temperature than that at HTmax (H-HTmax). The abrasive wear resistance was evaluated using Rubber Wheel abrasion test (three-body-type). It was found that hardness and volume fraction of retained austenite (V) in the heat-treated specimens varied with the Mo content …

Evaluation Of Cassava Tuber Resistance To Deformation, Oladele Peter Kolawole Engr.

Oladele Peter Kolawole Ph.D

A study was carried out, hardness and resistant ability of cassava tuber was investigated, the study involved the use of laboratory penetrometer and a data lodger. Hand-drilling machine was fitted with a 500mm diameter blade. These devices were powered manually and by application of electricity. Forces were applied by allowing direct cutting of the tubers using rotating sharp blade. The penetrometer was used to test the strength of fresh tuber. The result obtained indicated that cassava tuber hardness increases with the reduction of moisture content. The penetration force of 5.4 Newton at 70% moisture content wet basis was recorded while …

Influences Of Sample Preparation On The Indentation Size Effect And Nanoindentation Pop-In On Nickel, Zhigang Wang

Doctoral Dissertations

Careful experiments were performed with a well characterized indenter to systematically investigate the influences of sample preparation on the indentation size effect (ISE) and nanoindentation pop-in behavior in nickel. The Ni (100) surface was prepared by electropolishing and then damaged in a controlled way by polishing with alumina slurry. The damaged layer was systematically removed in steps by colloidal silica polishing (0.02 µm (micrometer)) with the pop-in behavior statistically characterized and the depth dependence of the hardness measured at each step. AFM observation revealed that the electropolished surface is free from scratches, and has the largest roughness. Numerous scratches were …

Treatment Technology Validation For Water Softening Technology, Caitlin Brown, Nathan Dillon, Kevin Tweeten, Peixi Yan, Kayla Lester, Tim Lewis

Senior Design

MT Hard Water of Montana Tech of the University of Montana submits Task 3: Treatment Technology Validation for Water Softening Technology as an entry into the 2012 WERC Environmental Design Contest.

Currently, there are several commercially available technologies that treat water hardness. The objective of this project is to develop a strategy to evaluate and validate different water hardness treatment technologies. MT Hard Water (MTHW) has studied several technologies including: electromagnetic water treatment, ion exchange, and reverse osmosis. For validation purposes, an electromagnetic water treatment system (ScaleRID) was selected according to the WERC task description.

Effect Of The Austenitising Heat Treatment On The Microstructure And Hardness Of Martensitic Stainless Steel Aisi 420, Lilian D. Barlow, Madeleine Du Toit

Faculty of Engineering and Information Sciences - Papers: Part A

The effect of austenitizing on the microstructure and hardness of two martensitic stainless steels was examined with the aim of supplying heat-treatment guidelines to the user that will ensure a martensitic structure with minimal retained austenite, evenly dispersed carbides and a hardness of between 610 and 740 HV (Vickers hardness) after quenching and tempering. The steels examined during the course of this examination conform in composition to medium-carbon AISI 420 martensitic stainless steel, except for the addition of 0.13% vanadium and 0.62% molybdenum to one of the alloys. Steel samples were austenitized at temperatures between 1000 and 1200 C, followed …

Measuring The Nanoindentation Properties Of Alendronate-Time Treated Canine Cortical, Folorunso Ashaolu

Master's Theses

This study examines the nanoindentation (energy inclusive) properties of 0.2 mg/kg alendronate treated ribs at one and three years against a vehicle treated control in a fresh-frozen, non-cold-mounted, condition. This was to verify if the tissue-level properties for 0.2 ALN treated beagles would increase because of an increased level of mineralization despite a microdamage increase.

A total of twelve (12) skeletally mature (1–2 years old) female beagle dogs were treated daily for three years and one year with oral doses of vehicle (VEH, 1 mL/kg saline) or alendronate (ALN, 0.2 Merck, Rahway, NJ). The 0.2 mg dose corresponds, on a …

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

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

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

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 …

Degradation Of Physical Properties Of Different Elastomers Upon Exposure To Palm Biodiesel

A.S. Md Abdul Haseeb

Biodiesel, as an alternative fuel, is gradually receiving more popularity for use in internal combustion engines. However questions continue to arise with regard to its compatibility with elastomeric materials. The present work aims to investigate the comparative degradation of physical properties for different elastomers [e.g. ethylene propylene diene monomer (EPDM), silicone rubber (SR), polychloroprene (CR), polytetrafluroethylene (PTFE) and nitrile rubber (NBR)] upon exposure to diesel and palm biodiesel. Static immersion tests in B0(diesel), B10 (10% biodiesel in diesel), B20, B50 and B100(biodiesel) were carried out at room temperature (25 °C) for 1000 h. Different physical properties like, changes in weight …

Addition Of Cobalt Nanoparticles Into Sn-3.8ag-0.7cu Lead-Free Solder By Paste Mixing

A.S. Md Abdul Haseeb

Purpose - The purpose of this paper is to investigate the effects of addition Co nanoparticles on the characteristic properties of Sn-3.8Ag-0.7Cu solder. Design/methodology/approach - Cobalt (Co) nanoparticles were added to Sn-Ag-Cu solders by thoroughly blending various weight percentages (0-2.0 wt%) of Co nanoparticles with near eutectic SAC387 solder paste. Blending was done mechanically for 30 min to ensure a homogeneous mixture. The paste mixture was then reflowed on a hot plate at 250°C for 45 s. The melting points of nanocomposite solder were determined by differential scanning calorimetry. Spreading rate of nanocomposite was calculated following the JIS Z3198-3 standard. …

Hardness And Microstructural Gradients In The Heat Affected Zone Of Welded Low-Carbon Quenched And Tempered Steels, W Pang, N Ahmed, D Dunne

Faculty of Engineering and Information Sciences - Papers: Part A

This paper concentrates on the form of the hardness gradient in the heat affected zones (HAZs) produced by submerged arc welding of two low-carbon Q & T steels. The results show unequivocally that the gradient differs from that found in steels of lower carbon equivalent in that the peak HAZ hardness is displaced from the grain coarsened heat affected zone (GCHAZ) into the grain refined heat affected zone (GRHAZ). Weld thermal cycle simulation has been used to confirm the results obtained from actual welds and to clarify the cause of this unexpected phenomenon.

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 …

Nanoindentation Of Annealed And As-Sputtered Thin Films Of Nickel Titanium Shape Memory Alloys, Matthew Tyson Lewis

Master's Theses

The bottom-up processing techniques used for making Microelectromechanical systems (MEMS) devices can produce material properties different from bulk processing. The material properties must be evaluated with the process parameters used and for changes in the process parameters. The mechanical properties are needed to design MEMS devices. A material of interest for MEMS devices is nickel titanium (NiTi) shape memory alloy (SMA) because of the high work output (~107 J/m3). This thesis will focus on the fabrication of thin film NiTi by DC magnetron sputtering deposition and testing mechanical properties of the fabricated films by nanoindentation. Thin film NiTi SMA was …

Compatibility Of Elastomers In Palm Biodiesel

A.S. Md Abdul Haseeb

In recent time, environmental awareness and concern over the rapid exhaustion of fossil fuels have led to an increased popularity of biodiesel as an alternative fuel for automobiles. However, there are concerns over enhanced degradation of automotive materials in biodiesel. The present study aims to investigate the impact of palm biodiesel on the degradation behavior of elastomers such as nitrile rubber (NBR), polychloroprene, and fluoro-viton A. Static immersion tests in B0 (diesel), B10 (10% biodiesel in diesel), B100 (biodiesel) were carried out at room temperature (25 °C) and at 50 °C for 500 h. At the end of immersion test, …

Methods For Characterizing Mechanical Properties Of Wood Cell Walls Via Nanoindentation, Yujie Meng

Masters Theses

Nanoindentation is a method of contacting a material whose mechanical properties are unknown with another material whose properties are known. Nanoindentation has the advantage of being able to probe a material’s microstructure while being sensitive enough to detect variations in mechanical properties. However, nanoindentation has some limitations as a testing technique due to the specific formation and structure of some biomaterials. The main objective of this research is to identify any factors that influence the nanoindentation measurement of wood cell walls (a typical biomaterial).

The function of the embedding media in describing the properties of wood cells is poorly understood. …

Tribological Comparison Of Traditional And Advanced Firearm Coatings, Greg Boban

Master's Theses

The objective of this project is to find which type of coating has the best performance characteristics for finishing firearms. This is accomplished by measuring and comparing several performance characteristics, such as: adhesion, hardness, wear resistance, friction control, and corrosion resistance. Appearance is not a factor since any exterior coating that is flashy can be subdued or camouflaged with special purpose paints, which have proven durable enough for such purposes. Cost will not be a limiting factor for this experiment, but will be discussed in the conclusion as a secondary concern. This data will be used to identify the best …

Nanomechanics Of Muscovite Subjected To Nanoindentation And The Pertinent Indentation Size Effect, Hang Yin

LSU Master's Theses

Two groups of nanoindentation experiments, including repeated loading tests and monotonic loading tests, were performed on muscovite with a sharp indenter tip and loading direction normal to the basal plane. By varying the maximum load in the first group of repeated experiments, influences of the load level can be examined on the modes of nanoscale deformation and the resulting estimation of hardness and elastic modulus. The incipient kink band concept was employed to interpret the observed dispersed loading-unloading hysteresis loops by considering formation and annihilation of IKBs. Furthermore, the material’s contact stiffness behavior was characterized by comparing the normalized unloading …

Mechanical And Chemical Characterization Of Biological Composite Structures, Bonnie Zimmerman

All Theses

A better understanding of the bioresponse of naturally occurring systems will help
to optimize the engineering of synthetic biomaterials. The aim of this thesis was to
characterize the mechanical and chemical behavior of two distinct biological composite
systems, human teeth and wool fibers. These mechanical and chemical properties were
also studied as a function of natural structure and environmental conditions.
Human teeth are composite systems consisting primarily of hydroxylapatite and
protein. This project investigated how the use of clinical dental treatments and
procedures, such as whitening and etching, affects mechanical properties. Analysis of
nanoindentation with the Oliver-Pharr model provided elastic …

Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications

A.S. Md Abdul Haseeb

For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are higher than …

High-Throughput Screening Of Shape Memory Alloy Thin-Film Spreads Using Nanoindentation, Arpit Dwivedi, Thomas J. Wyrobek, Oden L. Warren, Jason R. Hattrick-Simpers, Olubenga O. Famodu, Ichiro Takeuchi

Faculty Publications

We have demonstrated the utility of nanoindentation as a rapid characterization tool for mapping shape memoryalloy compositions in combinatorial thin-film libraries. Nanoindentation was performed on Ni–Mn–Al ternary composition spreads. The indentation hardness and the reduced elastic modulus were mapped across a large fraction of the ternary phase diagram. The large shape memoryalloy composition region, located around the Heusler composition (Ni₂MnAl), was found to display significant departure in these mechanical properties from the rest of the composition spread. In particular, the modulus and the hardness values are lower for the martensite region than those of the rest of the …

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

Nanoindentation in conjunction with piezoresponse force microscopy was used to study domain switching and to measure the mechanical properties of individual ferroelectric domains in a tetragonal BaTiO₃ single crystal. It was found that nanoindentation has induced local domain switching; the a and c domains of BaTiO₃ have different elastic moduli but similar hardness.Nanoindentationmodulus mapping on the a and c domains further confirmed such difference in elasticity. Finite element modeling was used to simulate the von Mises stress and plastic strain profiles of the indentations on both a and c domains, which introduces a much higher stress level than …

Friction Stir Welding Of High-Strength Automotive Steel, Eric Michael Olsen

Theses and Dissertations

The following thesis is a study on the ability to create acceptable welds in thin-plate, ultra-high-strength steels (UHSS) by way of friction stir welding (FSW). Steels are welded together to create tailor-welded blanks (TWB) for use in the automotive industry. Dual Phase (DP) 590, 780, and 980 steel as well as Transformation-Induced Plasticity (TRIP) 590 steel with thicknesses ranging from 1.2 mm to 1.8 mm were welded using friction stir welding under a variety of processing conditions, including experiments with dissimilar thicknesses. Samples were tested under tensile loads for initial determination if an acceptable weld had been created. Acceptable welds …

Effect Of Solution Annealing Temperature On Structure And Mechanical Properties Of En Aw 2024 Aluminium Alloy, M Fujda, R Mišičko, L Rusňáková, M Sojko

Journal of Metals, Materials and Minerals

The effect of solution annealing temperature on the change of microstructural and mechanical properties of EN AW 2024 aluminium alloy was investigated using a metallographic analysis, Vickers hardness measurement and tensile test. An intensive growth of solid solution grains was the result of the increase of solution annealing temperature by the finely dispersed particles dissolved during applied annealing process. The role of these finely dispersed particles was to inhibit the recrystallization process and grain growth of solid solution matrix through its pinning effect on the migrated solid solution grain boundaries. Observed changes of the microstructure involved the strength decline and …

Multilayered Systems Of Nanostructured Tib2 Thin Films And Its Mechanical Properties, N Panich, P Wangyao, S Hannongbua, P Sricharoenchai, S Sun

Journal of Metals, Materials and Minerals

This study focuses on the development of single and multilayer TiB2 coatings with Ti interlayer with the aim of improving the mechanical integrity of the coating-substrate system. The nanostructured TiB2 thin films and multilayered coatings were deposited on high speed steel substrates by magnetron sputtering. The resultant coating systems were evaluated with respect to microstructure, fractured cross-section and fundamental properties such as cross-sectioned fracture, surface roughness, hardness, modulus and coating adhesion to the substrate. It was found that the adhesion strength of TiB2 coating to HSS substrate could be significantly enhanced in the multilayer system, and by a proper combination …

The Relationship Between Reheat-Treatment And Hardness Behaviour Of Cast Nickel Superalloy, Gtd-111, P Wangyao, V Krongtong, P Tuengsook, W Hormkrajai, N Panich

Journal of Metals, Materials and Minerals

he microstructure of cast polycrystalline nickel base superalloy, GTD-111, operated for long-term services were investigated by SEM after different re-heat-treatment conditions. It was found that the exposed specimen after long-term service could be recovered in some extent by re-solution treatment followed by two-step aging treatment. The obtained dispersed precipitation of gamma prime particles was more uniform than those of the long-term exposed microstructure. The results showed that the couple of the lower (1125°C) and/or higher (1175°C) solution annealing temperatures resulted in less total volume fraction of coarse gamma prime precipitates and less homogeneous distribution in microstructure than the medium (1150°C) …

Top-Down Structure And Device Fabrication Using In Situ Nanomachining, Xiaodong Li, Xinnan Wang, Qihua Xiong, Peter C. Eklund

Faculty Publications

We demonstrate the potential of an alternative tool for the fabrication of nanoscale structures and devices. A nanoindenter integrated with an atomic force microscope is shown to be a powerful machine tool for cutting precise length nanowires or nanobelts and for manipulating the shortened wires. We also demonstrate its utility in cutting grooves and fabricating dents (or periodic arrays of dents) in ZnSnanobelts. This approach permits the direct mechanical machining of nanodevices that are supported on a substrate without the inherent complications of e beam or photolithography.

Mechanics Of Hydrogenated Amorphous Carbon Deposits From Electron-Beam-Induced Deposition Of Paraffin Precursor, W. Ding, D. A. Dikin, X. Chen, R. D. Piner, R. S. Ruoff, E. Zussman, X. Wang, Xiaodong Li

Faculty Publications

Many experiments on the mechanics of nanostructures require the creation of rigid clamps at specific locations. In this work, electron-beam-induced deposition(EBID) has been used to depositcarbonfilms that are similar to those that have recently been used for clamping nanostructures. The film deposition rate was accelerated by placing a paraffin source of hydrocarbon near the area where the EBIDdeposits were made. High-resolution transmission electron microscopy, electron-energy-loss spectroscopy, Raman spectroscopy, secondary-ion-mass spectrometry, and nanoindentation were used to characterize the chemical composition and the mechanics of the carbonaceous deposits. The typical EBIDdeposit was found to be hydrogenated amorphous carbon (a-C:H) having …

Nanomechanical Characterization Of Cavity Growth And Rupture In Hydrogen-Implanted Single-Crystal Batio3., Young-Bae Park, Patrick Nardi, Xiaodong Li, Harry A. Atwater

Faculty Publications

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 …