Around 23% of the world’s energy consumption results from rubbing contacts, in which 20% is used to overcome friction and 3% is due to wear and the consequent failure. The implementation of lubricants and effective lubricant additives are indispensable to reduce friction and wear of rubbing materials. Protic Ionic Liquids (PILs), which are easily obtained by proton transfer from a Brønsted acid to a Brønsted base, have shown great potential to be used as lubricants due to their structures and tunable properties. In this study, two kinds of novel PILs, bis(2-hydroxyethylammonium) succinate (DSu) and tri-[bis(2-hydroxyethylammonium)] citrate (DCi), were synthesized and tested as lubricant additives. The tribological behavior of the two PILs is studied as additives in 1 wt. % to a base synthetic lubricant (PAO) for steel-steel contact under different temperatures (room temperature and 100°C) and normal loads (3 N and 4 N) using a ball-on-flat reciprocating tribometer. When 1 wt. % of any PILs is added into PAO, friction is reduced compared to that with neat PAO at all temperatures and loads studied, and good anti-wear performance is also obtained under the higher temperature studied. Particularly, 1 wt. % DCi +PAO shows the best high-temperature tribological behavior under 4N, with friction and wear reductions of 33% and 35%, respectively.

Titanium alloys have a wide range of application in the field of automotive, biomedical and the civil industry due to its excellent material properties such as high thermal resistance, high load bearing capacity and high corrosion resistance. However, the high cost of machining titanium limits its application in aerospace and shipbuilding industry. Minimum quantity lubrication (MQL) has emerged as a new lubrication technique to achieve sustainable and profitable machining, but multiple studies show that conventional cutting fluid in MQL is not sufficient to reduce the friction and the associated effects. Recently, ionic liquids have shown a great potential in reducing the friction and wear of materials in contact. This study focuses on using an environment-friendly protic ionic liquid (PIL) tri-[bis (2-hydroxyethylammonium)] citrate (DCi) as an additive to a biodegradable oil (BO) used as lubricant in a ball-on-flat reciprocating tribometer in the titanium-ceramic contact at three different frequencies (3Hz, 4Hz and 5 Hz) under different loads. Results show a maximum 50% reduction in friction coefficient and 23% wear reduction at a frequency of 5 Hz under a normal load of 2 N by using 1 wt% DCi as an additive to BO as compared to using neat BO as the lubricant.

Lubricants play a vital role in improving energy efficiency and reducing friction in any type of frictional contact. The automotive industry is facing strict regulations in terms of emissions from the petroleum fuel. Strict government norms are compelling automotive manufacturers to push their technological limits to improve the fuel economy and emissions from their vehicles. Improving the efficiency of the engine will ultimately result in saving fuel thus improving the fuel economy of the engine. Concerning energy consumption; 33% of the fuel energy developed by combustion of fuel is dissipated to overcome the friction losses in the vehicle [1]. Out of this, 11.56% of the total fuel energy is lost in engine system. The distribution of this 11.56% fuel energy lost in engine system includes 3.5% consumed in bearings, 1.16% in pumping and hydraulic viscous losses, 5.2% and 1.73% consumed in piston assembly and valve train respectively [1]. If we consider losses only in bearings, piston assembly and valve train it results in 10.4% energy loss as compared to the total energy generated by the fuel. In the last decade, ionic liquids have shown potential as lubricants and lubricant additives. This study focusses on the use ionic liquids as additives for friction and wear reduction resulting in energy conservation in an internal combustion engine. In this work, the contact between piston ring and cylinder wall was simulated using a ball-on-flat tribometer. Most of the engine oils are based on mineral oils and results showed that adding 1% of the ionic liquid to mineral oil reduced friction loses by 27% [2], which corresponds to conserving 2.8% of fuel energy if just the frictional loss in piston assembly, valve train and bearing are considered. In the United States, there are 253 million vehicles on average consuming 678 gallons of fuel per year [3], the use of ionic liquid can save an estimated 4.8 billion gallons of fuel per year, which results in estimated saving of 11.56 billion dollars.

A significant amount of energy dissipates from frictional losses of moving components in machinery and devices in industry. This contact friction leads to the wear and eventual failure of industrial mechanical components over extended time through adhesion, abrasion, fatigue, or corrosion. Frictional losses could be mitigated by utilizing more effective lubricants, which would allow the translating surfaces to slide over one another more fluently. There is reason to study eco-friendly alternatives over traditional lubricants to reduce negative impact to the environment. The implementation of Ionic Liquids (ILs) as additives to oil-based lubricants is a development in tribology with the potential to lower the friction coefficient and reduce wear. When carbon nanotubes are dispersed into these ionic liquids, the reduction of losses due to friction and wear can be even greater. In this experiment, single-walled carbon nanotubes (SWCNTs) of four concentrations, 0 wt.%, 0.01 wt.%, 0.02 wt.%, and 0.03 wt.% were dispersed in a room temperature ionic liquid, Trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl) phosphinate, or [THTDP][Phos] for short, to form four homogeneous mixtures. Then, each mixture was added in 1 wt.% to a base vegetable oil. Friction tests were also conducted with pure vegetable oil for comparative purposes. The experiments consist of a pin-on-disk rotational tribometer and a ball-on-flat reciprocating tribometer both applying a steel-steel (AISI 52100) contact to evaluate the lubricating ability of combining SWCNTs and ILs as lubricant additives. The load, speed, wear radius, sliding distance, and duration of the experiment were held constant to isolate lubrication as the experimental parameter. Optical microscopy (OM), thermogravimetric analysis (TGA), and viscometer analysis were utilized after experimentation to analyze and discuss the wear mechanisms of the worn surfaces. Results differed between rotational and translational experiments, with the rotational results yielding a decrease of 14.21% in wear loss with the VO+1%[THTDP][Phos] lubricant. The translational results yielded a continuous decrease in wear loss with the increase in SWCNT wt.%.

In manufacturing processes, the cost of tooling contributes to a significant portion of operating costs. Several papers have been dedicated to various improvements on tool life, including monitoring the effect of temperature conditions and flood cooling. Flood cooling is not economical, so research has also been done to investigate minimum quantity lubrication and the effects of different additives, such as nanofluids. Another additive, ionic liquids, have become popular in tribological studies because they have unique properties that allow them to form ordered molecular structures, which is ideal in lubrication. Research has proven ionic liquids to be effective in reducing wear and friction coefficients. Currently, utilizing ionic liquids specifically to reduce tool wear has been almost exclusively limited to titanium and steel applications. The goal of this study is to improve tribological performance of the subtractive manufacturing process using ionic liquid add-ins to widely available machine shop coolants and oils. A series of reciprocating ball-on-flat experiments will be conducted using a 1.5mm diameter 250 Chrome Steel G25 ball and 6061-T6 aluminum disk to simulate cutting conditions often seen in manufacturing processes. 6061 Aluminum is an alloy commonly seen in machine shops and large-scale manufacturing scenarios because of its versatile material properties and wide availability. The tests were run at constant sliding distance, velocity and load. The lubricating mixtures were prepared by adding 5 wt % of a phosphonium based ionic liquid, Trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)amide ([THTDP][NTf2]), to the base fluids Trim Sol™ emulsion fluid and Mobilmet™ 766 high performance neat cutting oil. The addition of the ionic liquid to both base lubricants (oil and coolant) increased the friction coefficient (18.60% and 4.89%, respectively) while the wear volume was reduced (28.75% and 7.84%, respectively). The results for the oil provided evidence that the ionic liquid did have an effect to reduce wear, however, the same conclusion could not be drawn for the coolant.

In this study, the tribological behavior of the Trihexyl tetradecylphosphonium-bis(2,4,4-trimethylpentyl)phosphinate [THTDP][Phos] ionic liquid with and without single-wall carbon nanotubes (SWCNT) dispersion as a thin boundary layer was intended for investigation. However, the surface heat treatment process was not sufficient to form a thin film on the sample surfaces. Thus, in each test condition, the lubricating agents were used as external (liquid) lubricants. Specifically, [THTDP][Phos] and ([THTDP][Phos]+0.1 wt.% SWCNT) boundary film layers were applied on 6061-T6 aluminum alloy disk samples and tested under sliding contact with 1.5 mm diameter 420C stainless steel balls using a ball-on-flat linearly reciprocating tribometer. A commercially available Mobil Super 10W-40 engine oil (MS10W40) was also tested and used as this investigation’s datum. The tribological behavior of [THTDP][Phos] and ([THTDP][Phos]+SWCNT) boundary film layers was analyzed via wear volume calculations from optical microscopy measurements, as well as by observation of the transient coefficient of friction (COF) obtained through strain gauge measurements made directly from the reciprocating member of the tribometer. Results indicate the potential for reduction of wear volume and coefficient of friction in the IL lubricated steel-on-aluminum sliding contact through (SWCNT) dispersion in the ionic liquid. Wear results are based on measurements obtained using optical microscopy (OM). Results discussed display improved tribological performance for both [THTDP][Phos] and ([THTDP][Phos]+SWCNT) over baseline MS10W40 oil lubricant for both roughness values tested for the steel-on-aluminum contact. No measurable improvements were observed between [THTDP][Phos] and ([THTDP][Phos]+SWCNT) tests.

Methods for scalable surface texturing continues to receive significant attention due to the importance of micro-textured surfaces toward improving friction, wear and lubrication ability of mechanical devices. Controlled textures on surfaces act as fluid reservoirs and receptacles for debris and wear particles, reducing friction and wear of mating components. There are numerous fabrication techniques that can be used to create micro-sized depressions on surfaces, but each has limitations in terms of control and scalability. In the present study, modulation-assisted machining (MAM) is demonstrated as a viable approach to produce such textures, offering a potentially cost-effective approach for scalable production of these features on component surfaces. In this work, the wear behavior of several textured surfaces created by MAM was studied using a ball-on-flat reciprocating tribometer. Textured and untextured alloy 360 brass disks were mated with stainless steel AISI 440C balls under lubricated conditions and variable sliding distance. The textured surfaces exhibited noticeably reduced wear under the longer sliding distances and the tribological performance of the surfaces depended on the size of the micro-dimples. Wear mechanisms are elucidated from the optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) observations and the implications for using such surfaces in practice are briefly discussed.

The machining process monitoring, especially the tool wear monitoring, is very critical in modern automated gear machining environment which needs instant detection of cutting tool state and/or process conditions, quick final diagnosis and appropriate actions. It has been realized that the non-uniform hardness of the workpiece material due to the improper heat treatment can cause expedited tool wear and unexpected tool breakage, which greatly increases difficulties and complexities in monitoring the tool conditions in gear cutting. This paper provides a solution to detect the wear conditions of the gear milling cutter in the cutting of workpiece materials with hardness variations using the audible sound signals. In this study, cutting tools and workpieces are prepared to have different flank wear classes and hardness variations respectively. A series of gear milling experiments are operated with a broad range of cutting conditions to collect sound signals. A machine learning algorithm that incorporates support vector machine (SVM) approach coupled with the application of time and frequency domain analysis is developed to correlate observed sound signals’ signatures to specified tool wear classes and workpiece hardness levels. The performance evaluation results of the proposed monitoring system have shown accurate predictions in detecting tool wear conditions and workpiece hardness variations from the sound signals in gear milling.

The lubricating ability of one halogen-free and one halogen-containing phosphonium-based ionic liquids are investigated as neat lubricants, lubricant additives and thin lubricant layers in steel-steel contact. The use of the ionic liquids in any of the three lubricating methods reduced friction and wear compared to a base mineral oil. The halogen-free ionic liquid outperformed the halogen-containing ionic liquid in the three methods of lubrication. The highest friction and wear reduction were obtained when ionic liquids were used as neat lubricants. Under this condition, friction reductions of 37.21% and 25.73 %, and wear reduction of 47.12% and 41.18% compared to the based mineral oil were obtained for the halogen-free and halogen-containing ionic liquids respectively. The wear mechanisms and surface interactions are discussed in terms of ionic liquid-metal surface interactions from optical and SEM images and EDS analysis.

The surface interactions and tribological behavior of titanium-steel contact have been previously studied under the application of several commercial Ionic Liquids (ILs). In certain cases, superior anti-wear characteristics have been experienced when lubricating using ILs. This is often attributed to the development of a protective tribolayer that forms during application. One anion in particular amide, [Tf2N], has exhibited these characteristics with particularly positive results. However, amide is an anion that contains halogens, which are toxic and can cause harm if not handled properly. Due to the toxicity of most lubricants there has been a growing need to transition to bio-lubricants due to their low impact to the environment. This particular work will investigate the use of Trihexyltetradecylphosphonium, [P6,6,6,14]-+, cation with anion decanoate [Deca] as a non-toxic alternative to amide [Tf2N]. [P6,6,6,14]-+[Deca] and [P6,6,6,14]-+[Tf2N] will be compared as additives (1.0 and 2.5 wt. %) in Coffee Bean oil (CB) for lubrication of titanium-steel contact at room temperature. In this work, tests are conducted using a ball-on-flat reciprocating tribometer as per ASTM G133 with lubricated titanium-steel contact. An AISI 420C stainless steel ball is used on a Grade 5 6Al-4V titanium alloy disk specimen. Friction and wear volume are measured, examined, and discussed.

This work will provide a method to characterize a variety of novel high performance lubricants. In particular, surface tension and evolution of the contact angle on a variety of surfaces over one hour were recorded. Contact angles were measured using a ramé-hart Goniometer. Surface tension is measured with the same device using the pendant drop method. Fluids studied here include: trihexyltetradecylphosphonium bis(trifluoromethyl-sulfonyl) amide ([THTDP][NTf2]), trihexyltetradecyl-phosphonium decanoate ([THTDP][Deca]), 1-ethyl-3-methyl imidazolium trifluorosulfonyl imide ([EMI][NTf2]), and 1-ethyl-3-methyl imidazolium trifluoromethanesulfonate ([EMI][FMS]). Contact angles were measured on the following surfaces: AISI 52100 stainless steel disks polished to 0.01–0.05 μm, Kapton, SU-8, Teflon, and glass slides. The resultant change in roughness on 52100 steel disks was measured to provide insight into the corrosive properties of each liquid.

A supercharger is a mechanical device that can be added to an engine of a car to increase engine power. It works by sucking air in at atmospheric pressure into the rotors and compressing it at high revolutions per minute. With the rotors spinning at high speeds, the supercharger gears are exposed to high values of friction and wear, which results in a reduction of their service life. Ionic liquids (ILs) are substances that possess unique lubricating abilities when added to base oil or when used as neat lubricants. Properties include low volatility, non-flammability, as well high thermal resistance. These liquids are able to form ordered layers and tribofilms on the contacting surfaces which further protects the surface materials. In this work, the effect of adding ILs to low viscosity synthetic oil used to lubricate gears and to organic oil was investigated in the reduction of friction and overall wear of superchargers. Mobil 1 5W-30 Full Synthetic Engine Oil (MS) was used as a control and compared to coffee bean oil (CB). Additionally, the performance of these oils was observed with ionic liquids as additives at 1 wt. %. The chosen IL consisted of the cation Trihexyltetradecylphosphonium, [P 6,6,6,14 ] + , with the anion Bis(trifluoromethylsulfonyl) amide, [NTf 2 ] − . Lubricated flat disks of AISI 52100 stainless steel and 420C steel balls were studied using a Pin-on-Disk configuration. A total sliding distance of 500 meters was tested with a wear track diameter of 20 mm. Wear volume and average friction coefficient were measured according to ASTM-G99. Results showed that the addition of the ILs to the CB and MS reduced friction coefficient of the steel disks at medium speeds, and wear values achieved were comparable to the friction observed. The wear width values were also found to be reduced at medium speeds.

Gear milling is one of the common gear manufacturing processes. In gear milling, the cutting edge of the cutting tool has an identical profile with the profile between gear teeth, and the cutting tool travels along the axial direction of the gear blank to produce the gear tooth by tooth. Due to the high requirements about the dimensional accuracy and the surface roughness during the gear manufacturing process, it is very crucial to understand the influences of cutting conditions on those requirements to improve the quality of the product and increase the production rate. In this study, a machined gear blank made from 1018 cold-rolled steel was subjected to variable speed and feed-rates in a traditional milling operation using a standard gear-milling cutter. The effect of the variable speed and feed-rates were analyzed by measuring the total lead (helix) error, total profile (involute) error, and surface finish of each gear tooth subjected to the variable cutting conditions. The objective is to experimentally investigate the correlation between the cutting conditions, i.e. cutting speed and feed, with the accuracy and quality of the machined surface during the gear milling process.

In the operation of many common devices and processes, more than 60% of consumed energy is wasted in many common processes. These loses come in many forms including heat, friction, and vibration. Energy harvesters are devices that can recapture some of this waste energy and convert it into electrical energy. This work will focus on electrostatic energy harvesting devices that recapture vibrational energy. Electrostatic energy harvesters recapture mechanical energy when a conductive mass translates or deforms in an electric field. Polymer ionic liquid gel beads may serve as a useful replacement for fluid droplets in electrostatic energy harvesters. This work uses a recently developed method for reliable synthesis of polymer gel beads. These beads are synthesized using a micro-reactor, which generates monomeric droplets in a silicon oil carrier fluid. The monomer solution also contains a photoinitiator and cross linker, which enables the monomer to polymerize when exposed to UV light. The present work demonstrates a method to rapidly synthesize uniform beads with a variety of chemical compositions. These chemical compositions can be used to tune the electromechanical properties of the beads to improve performance in applications such as energy harvesting devices.

The purpose of this paper is to describe an independent study project required before graduation with a master of engineering degree in the department of mechanical engineering at Rochester Institute of Technology. The goal of this graduation project was to design and build a Pin-on-Disk Tribometer. The tribometer will be used by the department for future student research projects. This paper includes the details of the design process, such as adaptations from existing tribometers, all required calculations, and descriptions of the machining and assembly. New design concepts presented demonstrate simplicity of construction and use. The required calculations include shear and bending moments in the arm, bearing calculations, lead screw load analysis, counterweight balancing, torque calculations for selecting the correct motor, and strain calculations for determining the correct strain gage set-up. The paper details part selection, pricing, machining, and assembly. Mistakes and alternate design considerations are also discussed.

Vision loss knows no boundaries; it can affect anyone, of any age, income level, race, or ethnic background, at any time. Regardless of the level of visual impairment, vision loss can impact a person’s life and their ability to complete everyday tasks. One of the greatest challenges that a blind or deaf blind person faces is the ability to navigate safely and independently through the physical world. Traveling with little or no vision at all can be challenged and inaccessible, limiting the ability to work, go to school, take care of personal needs, or socialize with others. The purpose of this paper is to describe and discuss a multidisciplinary project to design and build a low cost, light weight “Intelligent Mobility Cane” prototype that will aid deaf-blind and blind persons in navigating surroundings via real-time tactile and directional force feedback and guidance. The system is designed for providing information about a physical surrounding environment to a user. The solution developed by the team is a handle that attaches to a white cane and provides directional feedback to the user using a roller assembly. The roller assembly uses four bearings that rotate in one direction or another to indicate the direction the user should move to avoid obstacles. A vibration motor with different patterns of vibration is also embedded in the handle to warn about objects at upfront. The ultra-sonic sensors are used to convey the information of the environment to the handle itself. The finished cane physically resembles a conventional cane therefore allowing the user to still be able to sweep the cane, tap and feel the ground. To evaluate the performance and usability of the designed handle, the authors visited Association of Blind and Visual Impaired Association, where they formed a group of blind and deaf-blind evaluators. The result of the evaluations was positive and several suggestions were shared by the group to improve the cane.

Samarium Cobalt (SmCo) magnets have been the magnet of choice for a variety of industries for many years due to their favorable magnetic properties. Their high coercivity, combined with a low temperature coefficient, make them the ideal permanent magnet for demanding high temperature applications. One of the biggest concerns with rare earth magnets is their brittleness. Samarium Cobalt magnets in particular are prone to fracturing during machining and assembly. In manufacturing, great care must be taken to avoid chipping or fracturing these magnets due to their brittle nature. There are two main grades of Samarium Cobalt magnets, 1:5 and 2:17. These ratios define the nominal ratio of rare earth to transition metal content. In this paper, an investigation is performed on the fracture toughness of permanent magnets based on the Samarium Cobalt 2:17 composition. Various techniques are used to characterize the microstructure of the material, and quantify the material properties. Optical microscopy is used to characterize the grain structure of the material and quantify the porosity of the material after sintering. By comparing the average grain size and fracture toughness of several samples, grain size was shown to not affect fracture toughness in standard material. Latent cracks in defective material showed no preference to follow grain boundaries, oxides inclusions or voids. River marks in fracture surfaces are seen through scanning electron microscopy, confirming the transgranular cracking pattern seen by Li et al [1]This suggests that the toughness of the material is an inherent property of the main phase, not of grain boundaries or contaminants. Samarium Cobalt magnets exhibit both mechanical and magnetic anisotropy due to the alignment of their crystal structure in the manufacturing process. Using Palmqvist indentation crack techniques, the magnetic orientation of the grains was seen to greatly influence the direction of crack propagation from the tip of the indenter. Measurements of fracture toughness using this technique produce highly scattered data due to this anisotropic nature of the material. Specimens loaded with the indenter axis parallel to the direction of orientation show normal Palmqvist cracks, while specimens loaded perpendicular to the direction of magnetization exhibit crack propagation initiating from the faces of the indenter. To better quantify the material’s brittleness, fracture testing is performed on specially prepared samples to obtain an absolute measure of fracture toughness (K1c). Results show that SmCo is measurably weaker than other magnetic materials such as neodymium iron boron magnets[2]. Furthermore, neither relative concentration of Samarium nor source of raw material show notable effect on the fracture toughness of the material.