Phosphor Bronze Research Articles

Fabrication of phosphor bronze/Al two-phase material by recycling phosphor bronze chips using hot extrusion process and investigation of their microstructural and mechanical properties

Despite the existence of conventional methods for recycling chips, solid-state techniques have become popular, whereby waste metals are directly recycled into consolidated products with the desired shapes and designs. We investigated the feasibility of recycling phosphor bronze chips through a hot extrusion process using aluminum powder as a metal binder for the fabrication of a metal-fiber-reinforced aluminum matrix composite. To do so, mixtures containing 20vol%–50vol% of chips were prepared, cold-compacted, and extruded. The quality of the consolidated samples was evaluated by determining the density of the fabricated composites and studying their microstructures. In addition, we performed tensile and hardness tests to evaluate the mechanical properties of the fabricated composites. We also analyzed the fracture surfaces of the samples to study the fracture mechanism as a function of the volume fraction of phosphor bronze chips in the fabricated composite. The results indicated that the most effective consolidation occurred in the sample containing 20vol% of chips extruded at 465°C in which the chips serve as ideal fibers for improving the mechanical properties, especially the ultimate tensile strength, in comparison with those of Al matrixes that contain no chips but are produced under the same conditions.

Viscoelastic analytical model and design of polymer-based bimodal piezoelectric motor

Polymers have attracted enormous attention due to their characteristics of low density and high energy density for potential applications in low weight piezoelectric motors. However, the viscosity of polymers presents a challenge to match two resonance frequencies of the longitudinal and bending modes of the bimodal piezoelectric motor. In this paper, polyphenylene sulfide (PPS)-based bimodal piezoelectric motor is researched. Concerning the viscoelasticity of PPS, the electromechanical coupling analytical model is established to describe the dynamics of the PPS-based motor by using the Kelvin-Voigt viscoelastic model. Based on the proposed model, the Taguchi method is adopted to match the resonance frequencies of the longitudinal and bending vibration. A PPS-based prototype motor is fabricated with optimized parameters. The frequency response characteristics, displacement response and electromechanical coupling coefficients are computed and compared to the finite element method and experimental results to validate the effectiveness of the model. The comparisons show that the proposed model is valid. The performance test demonstrates that the PPS-based motor can yield the maximal torque of 2 mNm with the stator weight of 5.4 g. Compared with the same volume of phosphor bronze material, 75% of weight reduction can be achieved.

Machining and Characterization of Micro-Channels Generated on Phosphor Bronze Using μ-EDM

Micro-Electro Discharge Machining ([Formula: see text]-EDM) is one of the nonconventional micro-machining processes in which electrical discharges are produced between the micro-sized electrodes — tool and workpiece immersed in dielectric fluid. The electrical discharges thus produced remove the workpiece material through melting and vaporization process and results in the creation of micro-craters. This paper focuses on machining of micro-channels on copper alloy — phosphor bronze plate using [Formula: see text]-EDM. Various micro-channels have been machined on phosphor bronze with input parameters: voltage, capacitance and pulse on-time varied at four levels. The experimental layout plans were designed with robust design technique — Taguchi-based L[Formula: see text] orthogonal array and the process parameters were optimized using optimization technique — Grey Relational Analysis (GRA). The dimensional aspects — depth, width, profile and surface roughness of machined channels were selected as output responses. The experimental results show that the parameters have individual and combined effect on responses. Analysis of Variance (ANOVA) technique has been used to explore the effect of parameters on responses. Detailed surface morphology of the machined features has also been analyzed using scanning electron microscope (SEM) and noncontact optical profiler images. As an extension of machining channels, Y-shaped channel has been machined on copper alloy which can be used for micro-fluidic applications.

A water distillation detritiation facility and its performance test

Water distillation is an effective method for detritiation of drainage from a nuclear power plant, and for the volume reduction of tritiated water from the cooling and safety systems of a nuclear fusion reactor. The height equivalent of theoretical plate (HETP) value is usually required for the conceptual column design to determine the height of the packing layer. A H2O-HTO water distillation engineering detritiation facility is established in Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics. Distillation in a total reflux mode for H2O-HTO with tritium activity of 13.5 MBq/kg has been performed in the column with 12 m height of packing layer and 261 mm inner diameter to measure the value of HETP for phosphor bronze bilayer gauze corrugated structured packing. When the column is operated at overhead pressure of 7 kPa and reflux rate of 25.0 kg/h, the pressure drop of the total column is just 2.0 kPa. The HETP value of the structured packing is 160 mm.

Friction Welding of Cast Iron and Phosphor Bronze

There is sometimes a need to fabricate machine parts that have the best properties of multiple materials while being economical at the same time. A prime example of such a scenario is with gears. Gears made out of cast iron are a poor choice because cast iron has poor impact resistance and is vulnerable to corrosion. The addition of phosphor bronze as an annulus to the cast iron hub in a composite gear provides the gear with those valuable resistances along with a superior intermeshing with mated gears. However, joining dissimilar materials such as cast iron to phosphor bronze is challenging when conventional welding techniques are employed. To overcome it, applying friction welding to join cast iron to phosphor bronze is focused in this thesis. The obtained results are analyzed and optimized for this particular combination of materials to facilitate their use in gears. The results show that there is an increased accumulation of graphite at the weld joints between cast iron and phosphor bronze for trials at higher (rotational) welding speeds, which leads to less favorable mechanical properties. At lower welding speeds, sound joints with acceptable mechanical and metallurgical properties were obtained.

Significance of tungsten disulfide on the mechanical and machining characteristics of phosphor bronze metal matrix composite

The phosphor bronze (PB) is widely preferred in various engineering applications due to its high strength, toughness, fine grain size, low coefficient of friction, and better corrosion resistance. The present work is to investigate the effect of tungsten disulfide (WS2) solid lubricant particle reinforcement in the phosphor bronze metal matrix composite (PBMC) through the mechanical and machining characteristics. The different variant of the composite is fabricated using stir casting technique by varying the volume percentage of WS2 particle from 0% to10%. The prepared PBMC samples are subjected to mechanical and machining (boring and high-speed turning) characterizations. The hardness (Brinell hardness) and flexural strength of the composites are examined as per the ASTM standard. The surface roughness (Ra) of the PBMC sample is analyzed through the boring and high-speed turning operations by varying the spindle speed, feed rate, and depth of cut. The scanning electron microscope (SEM) is employed to confirm the uniform dispersion of the reinforcement particle through the microstructural analysis. The presence of WS2 particles and other ingredients is ensured by X-ray diffraction analysis in the composites. The influence of WS2 reinforcement particles on tool life is analyzed on the PBMC4 (PBMC with 8% WS2) with the predefined machining parameters in the high-speed turning operation. The increase in WS2 particle (0–10%) improves the hardness (11.85%) and flexural strength in PBMC4 as compared to PBMC1 (PBMC with 0% WS2). At a higher spindle speed (1200 r/min), the Ra is reduced in PBMC1 as compared to 900 r/min, whereas the rest of the PBMC sample show higher surface irregularity at 1200 r/min.

A Monte Carlo Model for Pitting Corrosion in Phosphor Bronze Tape Used in Underground Power Transmission Cables

Life of underground oil-filled power transmission cables used with phosphor bronze tapes is greatly reduced by pitting corrosion and hence accurate prediction of the pit growth in these tapes becomes essential. In the present work, the probability distribution of corrosion pit depth on phosphor bronze tapes is calculated using probabilistic Monte Carlo simulations and compared with the measured pit depth distribution on samples of broken tapes which have been in service for about 50 y. This Monte Carlo simulation is performed on every stable pit that nucleates, propagates, and repassivates on the metal surface. Due to the random nature of pitting corrosion, the probability of failure of this class of cables can be simulated based on the Monte Carlo model. This paper shows that the simulated pit depth distribution is very similar to the experimental data. The results demonstrate that the Monte Carlo model by Engelhardt and Macdonald can be effectively applied to long-term field data of phosphor bronze tapes, even over 50 y. In addition, the probability of failure due to pitting corrosion can be evaluated analytically, without need of conducting expensive and time-consuming experimental campaigns. Therefore, this probabilistic pit depth distribution model will be a powerful tool in the decision-making strategy for the replacement of underground power transmission cables near their end of life.

OLIN BRASS ALLOY C42200

Abstract Olin Brass Alloy C42200 (Tradename: Lubronze) is a copper-zinc-tin alloy (tin brass). The mechanical properties and performance of C42200 are very similar to those of high-zinc brass alloys with the added benefit of improved resistance to stress relaxation. It is also a cost-effective alternative to phosphor bronze. This datasheet provides information on composition and physical properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-904. Producer or source: Olin Brass GBC Metals, LLC.

Investigate the effect of regenerator mesh on cooling performance

The regenerator is the heart of Stirling cryocooler. Proper selection of the regenerator mesh with high heat capacity in the operating temperature range is essential for the high effectiveness of the regenerator. To give better performance by the cryocooler, it is necessary to study characteristics of the regenerative matrix material, mesh size. In this paper, the physical properties of stainless steel and phosphor bronze were studied. In the FORTRAN software, the analysis was carried out by calculating the net refrigerating effect by considering different losses (conduction loss, temperature swing loss). The net refrigerating effect for mesh size 200, 250, 300, 350 and 400 was calculated. The optimum result obtained by cyclic analysis was considered for further validation. Two different displacer units were manufactured by filling 250 and 300 mesh separately. The testing was carried out for the same input conditions. The results were validated and compared with results obtained by thermal analysis.

Enhanced transfer efficiency of ultrasonic motors with polyimide based frictional materials and surface texture

In order to improve the transfer efficiency of the travelling wave ultrasonic motor (TRUM), the advanced polyimide-based (PI) frictional materials with high friction coefficient and elastic modulus were designed and prepared by hot press sintering. The friction coefficient of PI composite sliding against phosphor bronze was investigated by a flat-on-flat pattern tribo-meter simulated the running conditions of the TRUM. Besides, the micro-dimples with diameter of 300 μm and area density of 7.06% were fabricated on the surface of PI composites by laser ablation. The friction coefficient of the textured PI interface further increased compared to the smooth PI or polytetrafluoroethylene (PTFE) interface. Therefore, the mechanical output torque, rotational speed and transfer efficiency of the TURM with new frictional materials and surface texture were correspondingly improved. The enhancement mechanisms were discussed by analyzing the changes in friction coefficient and contact sate of the tribo-pairs.

Design and evaluation of a novel light arc-shaped ultrasonic motor

In order to achieve the application of ultra-sonic motors in small pan/tilt/zoom (PTZ), this study designed a light arc-shaped ultrasonic motor where the first-order longitudinal vibration mode and the second-order bending vibration mode were superimposed in the stator plane, in order to drive the rotation of the rotor. The stator was fabricated by phosphorous bronze and piezoelectric ceramic. ANSYS was used to simulate the motor performance in order to optimize its size and determine its operating mode. The motion trail of the end surface of the driving feet was also simulated. The frequency and amplitude of the motor prototype were measured using a three-dimensional (3D) laser vibration meter. The results, which were in good agreement with the simulation results, demonstrated that the prototype exhibited favorable vibration characteristics. The mechanical characteristics of the prototype were also tested. At an operating frequency of 126.5 kHz and an excitation signal of 350Vpp, the maximum rotating speed of the motor reached up to 230 rpm. Finally, the output torque of the motor configurations with single-stator and double-stator were proposed respectively was investigated. The output torque of the motor under the single-stator configuration reached up to 2.6×10-2 N·m, The double-stator which was 1.5 times greater than that under of single stator configuration. Conclusively, the designed motor is characterized by its light weight, high torque, and favorable output performances.

Mechanical and Tribological Properties of Polyimide Composites for Reducing Weight of Ultrasonic Motors

The travelling waves ultrasonic motors (TWUM) with nonmagnetic, large torque, high precision and simple structure was driven by frictional force, which had been applied aerospace, intelligent and precise instruments. In order to reduce the total weight of TWUM, the phosphor bronze stator with the biggest density among the all parts of TWUM (8.89 g/cm3) were substituted with light weight polymer or polymer composites. This study designed and prepared one types of low density polyimide (PI) composite (1.41g/cm3) reinforced with carbon fibers (CF) which can reduce the weight of stator over 85%. Importantly, this PI composite can meet the main requirements of TWUM, such as high elastic modulus, wear resistance, and suitable friction coefficient. The output stalling torque of TWUM with CF/PI stator still have 0.22 N·m (18.3% compared with TWUM with phosphor bronze stator). Moreover, this study systematically investigated the mechanical and tribological properties of CF/PI composite. For comparison, the pure PI, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) were also analyzed to reveal the wear mechanisms. The experimental results indicated that CF/PI had better wear resistance and lower friction coefficient than other polymer sliding against Si3N4. This light weight polymer composites would be an ideal candidate to reduce the weight of TWUM, which can broaden the lightweight application in the field of aerospace.

Ultrasonic motor with embedded preload mechanism

A linear/rotary ultrasonic motor, which is driven using a friction force, generally requires a preload mechanism between the slider/rotor and the stator. The preload mechanism is of considerable importance to the motor’s ability to produce a practical thrust/torque because the output thrust/torque is dependent on the friction force. However, the preload mechanism generally occupies a relatively large space as a proportion of the space for the entire motor, which may limit motor miniaturization. To overcome this limitation, a linear ultrasonic motor has been developed in this work with a slider that has an inherent preloading capability. The ultrasonic motor is composed of a phosphor bronze stator with piezoelectric ceramic plates and a U-shaped stainless steel slider. The stator is inserted into the slider with an interference fit, which means that the preload between the slider and the stator is applied mechanically. By selective excitation of the second or third resonance vibration modes of the stator, the slider can be driven bidirectionally. The maximum velocity, thrust and output power values of the proposed motor are 62.5 mm/s, 0.12 N and 1.01 mW, respectively. This simple but effective solution, which eliminates the need for an external preload mechanism, will contribute to progress in ultrasonic motor research and design.

Study on effects of ultrasonic vibration on sliding friction properties of PTFE composites/phosphor bronze under vacuum

This paper is a tribological problem extracted from the application of the ultrasonic motor under the vacuum. Nine frictional states were designed. Under the atmosphere and vacuum environment, the effects of longitudinal and torsional ultrasonic vibration modes on the sliding friction pair of phosphorus bronze and Polytetrafluoroethylene (PTFE) composites were studied. The results show that under vacuum, applying vertical or horizontal ultrasonic vibration can reduce the friction coefficient. However, comparing with sliding friction under ultrasonic vibration in atmosphere, the friction coefficient increases. With the increase of vacuum degree, the effect of friction reduction by ultrasonic vibration becomes weaker, which leads to the increases of the friction coefficient under high vacuum. The friction coefficient is almost no change under low excitation voltage. It is revealed that the increase of friction coefficient caused by ultrasonic vibration in vacuum is due to the decrease of air medium density, the reduction of acoustic levitation force and the increase of contact opportunity of friction pair.

Design and Material Analysis of a Suspension System in Scooter by using Finite Element Analysis Method

The principle part for a vehicle suspension is the compression spring system, which is fabricated for arresting shock impulse. Suspension system work on the principle of fluid transformation between compression and expansion cycle. Mostly the suspension system is used in motorcycles for providing better handling, prompt braking, safety, and comfort by keeping the passengers isolated from road noise, bumps, and vibration. The shock absorbers duty is to absorb or dissipate energy. In a vehicle, it reduces the effect of traveling over rough ground, leading to improved ride quality, and increase in comfort due to the substantially reduced amplitude of disturbances. In most of the cases, the spring which is used in the scooter suspension system is made up of beryllium copper, phosphor bronze and titanium, but in this research paper a scooter suspension system is designed and the designed suspension system is analyzed using ansys with different material properties. The composite material gives less deformation because of the high stiffness to load carrying capacity. So the Composite suspension system is recommended for two and three-wheeled vehicles.

Distilled water and ethyl alcohol boiling heat transfer on selected meshed surfaces

The article deals with the problem of pool boiling heat transfer enhancement on metal wire mesh coatings made of copper and phosphor bronze at nucleate boiling of distilled water and high purity ethyl alcohol under ambient pressure. The tests have been performed on horizontal samples containing different microstructures produced with the sintering technology. The samples were attached to the heating block with soldering. As a result of the experiments, boiling curves were obtained, describing the relationship between the dissipated heat flux and the superheat values for each specimen. A considerable augmentation of heat flux has been recorded for the meshed surfaces in relation to the smooth reference surface without any coating. Generally, the highest enhancement was recorded for the low superheat values. The presented test results have been discussed and then compared with selected correlations available in literature for nucleate boiling heat transfer on microstructure coated surfaces.

Metallurgical Analysis of Premature Failure of a Phosphor Bronze Worm Wheel

Worm drives are commonly used where large reduction in speed and greater transfer of torque are required within a small space. Phosphor bronze is normally used material for this application owing to its lower coefficient of friction and good wear and fatigue properties. This work presents a failure analysis of a worm wheel. Analysis revealed that around 40% of the teeth of worm wheel were broken. Failure mode was identified to be intergranular brittle fracture using scanning electron microscopy. A number of casting voids could be observed. In addition, network of intermetallic phases were present along the grain boundaries. These phases were identified to be Cu3Sn and Ni3P using elemental mapping through wavelength dispersive spectroscopy technique. These phases were found to have significantly higher hardness compared to the matrix and their precipitation along grain boundaries made the alloy susceptible to intergranular fracture even under small increase in service stress than nominal level.

A prototype handheld X-ray diffraction instrument.

A conceptual design for a handheld X-ray diffraction (HHXRD) instrument is proposed. Central to the design is the application of energy-dispersive XRD (EDXRD) in a back-reflection geometry. This technique brings unique advantages which enable a handheld instrument format, most notably, insensitivity to sample morphology and to the precise sample position relative to the instrument. For fine-grained samples, including many geological specimens and the majority of common alloys, these characteristics negate sample preparation requirements. A prototype HHXRD device has been developed by minor modification of a handheld X-ray fluorescence instrument, and the performance of the prototype has been tested with samples relevant to mining/quarrying and with an extensive range of metal samples. It is shown, for example, that the mineralogical composition of iron-ore samples can be approximately quantified. In metals analysis, identification and quantification of the major phases have been demonstrated, along with extraction of lattice parameters. Texture analysis is also possible and a simple example for a phosphor bronze sample is presented. Instrument formats other than handheld are possible and online process control in metals production is a promising area. The prototype instrument requires extended measurement times but it is argued that a purpose-designed instrument can achieve data-acquisition times below one minute. HHXRD based on back-reflection EDXRD is limited by the low resolution of diffraction peaks and interference by overlapping fluorescence peaks and, for these reasons, cannot serve as a general-purpose XRD tool. However, the advantages of in situ, nondestructive and rapid measurement, tolerance of irregular surfaces, and no sample preparation requirement in many cases are potentially transformative. For targeted applications in which the analysis meets commercially relevant performance criteria, HHXRD could become the method of choice through sheer speed and convenience.

EXPERIMENTAL ANALYSIS OF A SCREEN-COVERED GROOVE HEAT PIPE

In this research, a heat pipe with screen-covered groove capillary structure was experimentally analyzed. The heat pipe was manufactured from a copper tube with the external diameter of 9.45mm, inner diameter of 6.20mm, and a total length of 200mm. A Wire Electrical Discharge Machining, or Wire-EDM, was used to manufacture axial microgrooves in the heat pipe. A layer of phosphor bronze mesh #100 completed the capillary structure. Distilled water was the working fluid and the loading filling ratio was 60% of the evaporator volume. The condenser was cooled by air forced convection, the adiabatic section was insulated with fiberglass, and the evaporator was heated by an electrical resistor and it was insulated from the environment with aeronautic insulation. The heat pipe was tested in horizontal position, under different heat loads varying from 5 up to 30W. The experimental results showed that the screen-covered groove worked satisfactorily as a capillary structure.

Thermal Conductance and High-Frequency Properties of Cryogenic Normal or Superconducting Semi-rigid Coaxial Cables in the Temperature Range of 1–8 K

In this study, the characteristics of thin semi-rigid cables composed of different conductors and with outer diameters ranging from 0.86 to 1.19 mm were investigated at low temperatures. The thermal conductance was measured between approximately 1 and 8 K, and the frequency dependence of the attenuation in the cables was obtained at 3 K. The electrical conductors used in the cables were alloys: beryllium copper, brass, stainless steel (SUS304), phosphor bronze, cupronickel (CuNi), and niobium–titanium (NbTi). The thermal conductance of a commercial miniature coaxial cable with braided wires forming the outer electrical conductor was also examined for reference. The measured thermal conductance was compared to published data and that generated from material libraries and databases. Among the measured cables using normal metals, the semi-rigid cable composed of SUS304 conductors and a polytetrafluoroethylene insulator showed the lowest thermal conductance. The transmission performance of the semi-rigid cables using SUS304 or CuNi was improved by plating the central conductors with a silver coating of approximately \(3~{\upmu }\hbox {m}\) thickness, and their thermal conductance with the plating increased by approximately one order of magnitude. The superconducting NbTi semi-rigid cable exhibited the lowest thermal conductance of all the cables considered in the present study along with very small attenuation up to above 5 GHz.