Beryllium Copper Research Articles

A simple and efficient passive vibration isolation system for large loads in closed-cycle cryostats.

We present a system for passive damping of vibrations along three spatial degrees of freedom for cryostats equipped with closed-cycle coolers. The system, designed to isolate a payload of 30kg, consists of two stages of isolation for vibrations in the vertical direction. The first isolation stage incorporates a trapezoidal beryllium copper cantilever blade. The second stage is attached to the blade via a steel wire and consists of four extension springs with an extended length of 370mm. At 1.6K, the stages possess vertical resonance frequencies of 2.1 and 1.3Hz, respectively. The vertical length of the setup with a cumulative length of 580mm also acts as a pendulum with a resonance frequency of 0.65Hz. In the frequency band from 5 to 200Hz, the frequency-integrated acceleration decreased from 6.7 × 10-3 to 4.3 × 10-5 g along the horizontal direction and from 4.3 × 10-3 to 7.2 × 10-5 g along the vertical direction. This corresponds to a reduction in vibrations by factors of 156 and 60, respectively. Overall, we achieve a simple, robust, and cost-efficient vibration isolation system for upgrading standard-type cryostats.

Multi-Objective Parameter Optimization of Flexible Support System of Optical Mirror

During the processing of an optical mirror, the performance parameters of the bottom support system would affect the surface forming accuracy of the mirror. The traditional bottom support system has a large unadjustable support stiffness, which increases the difficulty of unloading the impact force generated by the grinding disc. In response to this scenario, a flexible support system (FSS) consisting of 36 support cylinders with beryllium bronze reeds (BBRs) and rolling diaphragms (RDs) as key components is designed. It is necessary to analyze the key components of the support cylinder to reduce its axial movement resistance, ensure a consistent force output of each support point. First, the internal resistance model of a flexible support cylinder is established, and the main factors of internal resistance are then analyzed. Thereafter, the multi-objective structural parameters of the BBR and RD are simulated in ANSYS using the control variable method. The optimal structural parameters of BBR and RD are determined by simulation. Finally, experiments are performed on the RD ultimate pressure, internal resistance of the support cylinder, and consistency of the force output of the FSS. The experimental results show that the support cylinder with the optimized design has good force output consistency, which provides a theoretical basis for the application of FSS in optical mirror processing.

Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy

Copper-Beryllium alloys have excellent wear resistance and high mechanical properties, they also possess good electrical and thermal conductivity, making these alloys very popular in a wide variety of industries, such as aerospace, in the fabrication of tools for hazardous environments and to produce injection molds and mold inserts. However, there are some problems in the processing of these alloys, particularly when these are subject to machining processes, causing tools to deteriorate quite rapidly, due to material adhesion to the tool’s surface, caused by the material’s ductile nature. An assessment of tool-wear after machining Cu-Be alloy AMPCOLOY 83 using coated and uncoated tools was performed, offering a comparison of the machining performance and wear behavior of solid-carbide uncoated and DLC/CrN multilayered coated end-mills with the same geometry. Multiple machining tests were conducted, varying the values for feed and cutting length. In the initial tests, cutting force values were registered. The material’s surface roughness was also evaluated and the cutting tools’ edges were subsequently analyzed, identifying the main wear mechanisms and how these developed during machining. The coated tools exhibited a better performance for shorter cutting lengths, producing a lower degree of roughness on the surface on the machined material. The wear registered for these tools was less intense than that of uncoated tools, which suffered more adhesive and abrasive damage. However, it was observed that, for greater cutting lengths, the uncoated tool performed better in terms of surface roughness and sustained wear.

The Influence of Friction Deformation on the Microstructure and Hardening of Beryllium Bronze

The peculiarities of the microstructure and properties of BrBNT1.7 beryllium bronze tape samples were studied: the samples were subjected to dispersion hardening as a result of quenching in a supersaturated solid solution and aging. Friction deformation in a dry friction mode provides additional effective hardening while maintaining increased plasticity (bending-and-unbending test).

A novel and simple method to improve thermal imbalance and sink mark of gate region in injection molding

Among the appearance defects of injection molded products, sink mark near the gate accounts for a large proportion, especially for the precision products that require a high appearance quality. The traditional method to relieve gate sink mark is to increase packing pressure and packing time. Even so, the problem cannot be completely solved. In current study, a three-dimensional numerical simulation method was employed to analyze the formation mechanism of gate sink mark. The analyses point out that high shear in the filling stage, melt refilling in packing stage and high mold temperature lead to the imbalance of shear heat generation and cooling between the gate and other regions, and finally result in the relatively high temperature and the sink mark defect in the gate region. Based on these results, a novel and simple method for improving gate sink mark by adding beryllium copper insert in the runner was proposed and implemented. Further simulation shows that the method is effective in eliminating the gate “hot spot” and improving the temperature uniformity of the entire product. The experiment results also prove that the heat sink mark in the gate area can be effectively avoided by using the mold with insert for both amorphous ABS and semi-crystalline PP products. The proposed method can not only solve the sink mark problem effectively, but also has the advantage of being simple and easy to achieve because the slide type side gate design is adopted.

Friction and Wear Behavior of C17200 Copper-Beryllium Alloy in Dry and Wet Environments

Friction and Wear Behavior of C17200 Copper-Beryllium Alloy in Dry and Wet Environments

Effect of blank-holder force on springback of ultra-thin copper sheets

After forming by plastic deformation, it’s rare that the part produced retains its shape perfectly after removing the tools, the shape and dimensions that the tools imposed on it. This change in shape is mainly due to springback. This study focuses on the springback of U-shaped channels made of thin sheets of beryllium copper alloy 0.1 mm thick. The intensity of springback depends on several factors of part geometry and process parameters. Among the parameters of the process, we investigated the clamping force, which is an essential factor influencing the final shape of the part. It is shown that the springback is inversly proportional to the clamping force. As a consequence, there is no significant change of the geometry of the final part. Indeed, uneder high clamping force, the internal stresses (already existing in the material) become very important, which makes it possible to attenuate significantly the local moment effect in bending. The result is an uniform distribution of residual stresses in the thickness of the sheet which is studied in this paper.

Structural strength of iso-polyhedral beryllium alloy rotating mirror for ultra-high-speed camera

This study aims to examine the influence law of polyhedron structure on the spatial mechanical properties of ultra-high-speed rotating mirrors. To this end, polyhedral beryllium alloy rotating mirrors are investigated on the basis of elastoplastic theory and finite element method. The maximum stress is located at the end position of the contact between the shaft and the mirror body. Stress increases with the number of mirror faces. The different structures have a negative stress gradient. The structural strength of rotating mirror is affected by the strength of the mirror body material in high-speed rotation of the tensile force of centrifugal force. The lateral deformation of the mirror surface is caused by the combined effect of compression of centrifugal force generated by the material of sharp-corner and the tretching of tensile force caused by the material at the centre of the mirror at high-speed rotation. The amount of mirror surface deformation is not proportional to the number of faces. The rotating mirror with iso-quadrangular structure has the best lateral deformation effect. This research provides a theoretical basis for the research and design of rotating mirrors with high potential value.

Mathematical modeling of heat transfer in the film-substrate-thermostat system during heating of an electrically conductive film by a high-density pulse current

Mathematical modeling of heat transfer in the film-substrate-thermostat system with a pulsed flow of high-density current through an electrically conductive film has been carried out. On the basis of the simulation, the analysis of the heating of a niobium nitride film with a high resistivity near the critical temperature of the transition to the superconducting state is made. The inhomogeneous heat conduction equation which is solved numerically, simulates heat transfer in the film-substrate-thermostat system for the third on the left and the first on the right initial boundary value problem. Using the symmetry of the problem, the parameter H is determined, which is equal to the ratio of the heat transfer of the film surface to its thermal conductivity; this parameter is necessary for effective heat removal. It is shown that effective heat removal from films can be provided by current-carrying and potential clamping contacts made, for example, of beryllium bronze. This makes possible to study the current-voltage characteristics of superconductors near the critical transition temperature to the superconducting state with high-density currents (104−105A/cm2) without significant heating of the samples.

Dry Sliding Behavior of Qbe-2 Beryllium Bronze against 38CrMoAlA Steel in Pneumatic Downhole Motor under Different Loads

In drilling engineering, the wear of tribo-pairs is the primary cause for the rapid failure of rotating seals in pneumatic downhole tools. In order to reduce the wear of tribo-pairs, a new type of rotating seals was designed in this work, which introduced copper alloys between the stator and rotor. To elucidate the wear and failure mechanism of the copper-steel tribo-pair rotating seals in pneumatic downhole motors, pin-on-disc dry sliding tests with Qbe-2 beryllium bronze pin against 38CrMoAlA steel disc under different loads were thus designed to simulate the friction and wear behavior of such tribo-pair. During the dry sliding process, the friction behavior of the copper pin would go through a running-in period and then become stable. As the load increases, the running-in period will be shortened, while the friction coefficient during the stable period decreases. Interestingly, a false stability occurs when the load is low. However, this phenomenon will disappear under heavy loads. The wear mechanism of the copper pins would change from adhesive wear to ploughing wear as the load increases, which is mainly related to the spalling of asperities and the filling of wear debris into the steel disc. The wear debris consists of copper and copper oxide. The surface roughness of the steel disc and copper pin decreased and the size of the wear debris increased with the increase of the load. The material removal mainly occurs on the copper pin, which will present a relatively small value under 45 N. On contrast, due to the filling of wear debris, the volume of the steel disc increased. Therefore, considering the value and stability of friction coefficients, as well as the wear amount of the sample, it would be better that such tribo-pair could work under 45 N. The present work will provide a fundamental understanding and solid support for systematically designing the tribo-pairs in pneumatic downhole tools under practical working conditions.

Simulation of the Heat Transfer Process of Superconducting Films in the Resistive State

The heat transfer in a contact–film–substrate system was analyzed under conditions in which the heat removal from a sample to the substrate is insufficient to avoid overheating of the sample. A method for increasing the heat removal from thin-film samples is proposed for low temperatures, when a high-density electric current passes through them. The property of an anomalously high thermal conductivity of copper at temperatures from 5 to 50 K is used as the main factor of the heat-sink intensification. The heat-conduction equation for the film–substrate system is solved numerically under the condition of an additional heat transfer to the potential contacts. It is shown that beryllium bronze contacts can provide an effective heat removal from samples of superconducting films in the resistive state under the conditions of a strong Joule heat release.

Selection of tools and cutting modes for turning small-sized high-precision parts of micro-wave electronics from beryllium bronze

Beryllium bronze has the property of plasticity after heat treatment, which is a decisive factor when choosing the material of conductors in unpressurized coaxial connectors. The presence of burrs on these parts according to technical requirements is not allowed. When turning details of beryllium bronze, difficult to remove burrs appear. The aim of the study is to select a tool and cutting modes for turning small-sized high-precision parts of microwave electronics from beryllium bronze, in which there are no burrs or their size and quantity are minimal. In this study, empirical methods are used in the form of experimental selection of cutting modes and tools for the purpose of combating burrs, and analytical methods in the form of analysis of the character of burrs using the provisions of the theory of metal cutting, analysis of factors affecting the formation of burrs during machining surface parts. On CNC lathes CITIZEN CINCOM studied typical of this type of production tools ten leading manufacturers of precision cutting tools for turning. As a result of the study, it was not possible to completely exclude the appearance of burrs during machining. The smallest size and the number of burrs were obtained when machining with carbide tools manufactured by Swiss companies Fraisa, Utilis, IFANGER, Applitec. TiAlN coating is well suited for beryllium bronze treatment. When turning with a new tool at low speeds, the number of burrs decreases, their character changes, they become small drop-shaped. The processing modes recommended by the tool manufacturer differ from those selected experimentally. For further use of the selection results, it is necessary to create a database of regulatory and reference information on the types of processing for specific materials, tools, machine tools according to the accuracy criteria, taking into account the minimization of the number and size of burrs.

Theoretical Investigation of a Pin Fin Heat Sink Performance for Electronic Cooling using Different Alloys Materials

Electronic cooling plays a role in removing the electronic equipment’s heat rate to prevent failure from occurring. Electronic cooling performance is based on many parameters, such as thermal characteristics and material type design. Pure aluminium, copper – aluminium, and aluminium - beryllium are selected for predicting the performance of a heat sink. It was observed that the presence of Aluminium-copper alloy raises the performance of the heat sink compared with that of the pure aluminium. In contrast, the heat sink performance using aluminium - beryllium alloy was less than that of the reference material (pure aluminium). It was found that the heat dissipated from the heat sink increases by 1.4 % with using aluminium-copper alloy instead of using pure aluminium while the heat dissipated drops by 2% with using aluminium - beryllium alloy compared with that of using pure aluminium. Further, the heat sink mass decreases with the use of the aluminium-beryllium and increases with using copper - aluminium instead of pure aluminium. Whereas the mass of the heat sink using aluminium-copper alloy is higher than that of the pure aluminium by 2.3% while the mass of the heat sink using aluminium - beryllium alloy is less than that of the pure aluminium by 2.4%.

Multi-phase ion-plasma Cu-Ti coatings deposited on copper and copper beryllium alloy

The paper presents outcomes of vacuum-arc plasma-assisted deposition of titanium, titanium nitride and copper on copper (C11000) and the hardened copper beryllium alloy (C17200) at a temperature of 320÷k330°C. The study has revealed that multi-phase coatings form when varying discharge currents generated by arc evaporators and supply sequences of producer gas (argon) and nitrogen. An X-ray phase analysis has demonstrated these coatings to consist of copper, titanium and CuTi, CuTi2 and TiN compounds. Another important outcome to emerge from the study is that ion-plasma processing results in ageing of copper beryllium alloy and furthers the formation of CuBe particles. The microhardness of Cu-Ti coatings is as high as 400÷540 HV0.02 provided that the elements are vacuum-arc deposited at a temperature of 320÷k330°C. The microhardness of a nitrogenized Cu-TiN surface layer is measured to be 760 HV0.05. The thickness of deposited coatings is within several micrometers, so the measured hardness hardly complies with the real characteristic of coatings because the indenter breaks a thin hard layer. In addition, vacuum-arc sputtering of titanium and copper cause metal drops on the surface, as a consequence, the hardness of coatings is below referential values.

Optimization of material of flexure spring by finite element analysis

Abstract Flexure spring is thin metallic disc used to allow relative motion by bending between the piston and the fixed support in compressor body. The flexure spring deforms by the force applied by piston and come back to its original position. As spiral arms cut from its surface, flexing takes place. The main object of this article is to optimize the spring material to enhance the service life of spring. The present article analyzes five different copper based alloys as these materials are having elasticity property. Initially the model was prepared in Catia software. The Finite Element Analysis (FEA) was carried out by applying boundary conditions. As the total displacement of piston is 10 mm so force is applied at the central hole in such a way that the spring will deform for 5 mm from mean position. Due to applied load stresses will develop in the flexure. The equivalent stress was observed for chosen materials. The equivalent stresses were compared with permissible stress for that material by considering factor of safety (FoS). The cold drawn copper and the Beryllium copper UNS C (TH02) found suitable for flexure spring having the stress within permissible limit. As stiffness is also important property for spring. The deformation was observed in FEA for these two materials by applying 1 N force. The stiffness was calculated. The material was selected which will give maximum stiffness. It was found that the Beryllium copper UNS C (TH02) shows the maximum stiffness.

Material selection for long life and high durability for special purpose type of flexure bearing

A special type of flexure bearings are installed to support a compressor motor and a displacer within a cryocooler which is used in space applications. The fatigue life of spring is a critical factor for such applications, to ensure that the cryocooler does not fail. The flexure spring is used in the setup of an eccentric type of flexure bearing. The present study analyzes various significant parameters and properties in selecting the best suitable material to achieve finite-fatigue life. To avoid a failure of such critical component, batch testing is carried out. The three materials which are compared with respective SN-curve are a] beryllium copper, b] Stainless Steel (3 0 4) and c] Titanium. The study has been carried out to find the best suitable material for flexure bearing. Finite Element Analysis (FEA) is used to understand flexure springs stress and displacement.

Formation of the structure and properties of composite materials based on copper powder during its reactionary mechanical alloying with titanium, carbon and oxygen

The results of studying the structure and properties of dispersion-strengthened composite materials of the Cu-Ti-C-O system obtained by reactionary grinding of copper powder with additions of titanium powder (0...5 wt%) and carbon in the form of graphite (0...1 wt%) in a high-energy ball mill of the attritor type in the presence of air. The regularities of the influence of titanium and graphite content on the hardness and electrical conductivity of the materials under study have been studied. It is shown that with an increase in the titanium content, the hardness increases and the electrical conductivity decreases. The hardness and electrical conductivity of materials under study dependences on the graphite content have the form of curves with maxima, which are observed at different values of the carbon content depending on the titanium content. By the method of X-ray phase analysis of the anode deposit of materials under study, it was found that the main strengthening phases are dispersion particles of titanium carbide. The composite materials under study of the Cu-Ti-C-O system, due to the combination of high electrical conductivity, hardness and recrystallization temperature, can be an alternative for replacing beryllium bronze in many fields.

Modelling and simulation of primary suspension springs used in Indian railways

Role of the primary suspension is very important when the vehicle is taking a turn or railway is negotiating a curve. It is therefore necessary to simulate the behavior of the primary suspension system of the railway using commercially available software to optimize the operating parameters of the suspension such as speed of the railway, curvature etc. In this work, primary suspension systems of the springs are modelled by considering material property variation, load variation and geometrical discontinuities. Both vertical deflections and axial deflection of the springs are considered for the analysis under the action of centrifugal force and gyroscopic couples. Generally, the primary suspension of the railcar is made by Chromium Vanadium (50CrV4) material. On the analysis using this material it was found that the outer wheel primary spring undergo shear failure while taking a turn of radius of curvature 175 m with a speed of 100Kmph. In order to avoid the shear failure, the radius of curvature of the turn should be either 252 m or 292 m. Also, the failure can be avoided by reducing the speed of the train less than 80 kmph at the 175 m turn. Shear stress values at 120 km/hour for chromium vanadium is 1385,4 MPa at 175 m radius, 1108.3 MPa at 252 m radium, 1028.3 MPa at 292 m radius. As the radius increases, less shear stress is observed. For maragaing steel, Shear stress values at 120 km/hour is 1268.48 MPa at 175 m radius, 1001.24 MPa at 252 m radium, 926.61 MPa at 292 m radius. Shear stress values at 120 km/hour for Beryllium copper is 1388.4 MPa at 175 m radius, 1110.5 MPa at 252 m radium, 1030.1 MPa at 292 m radius. The difference of 10–12% is observed between FEM results and analytical results.

Static and Model Analysis on Pneumatic Suspension by using Ansys Software

During the tractor movement, with being attached to the hitch-system working equipment over Rough road surfaces oscillation of the machine take place. These oscillations are a reason of pressure pulsations in the hydraulic hitch-system. The pressure pulse reduction in the tractor Hitch-system is important for increasing of the system components lifetime. Pressure oscillation damping in the tractor hydraulic hitch-system can reduce overall system oscillations and improve the driving control. The design of spring in suspension system is very important. In this project a shock absorber is designed and a 3D model is created using CATIA V5 R20. The model is also changed by changing the thickness of the spring. Structural analysis and modal analysis are done on the suspension system by varying material for spring, Spring Steel and Beryllium Copper. Analysis done in ANSYS 14.5. The analysis is done by considering loads, bike weight, single person and 2 persons. Structural analysis is done to validate the strength and modal analysis is done to determine the displacements for different frequencies for number of modes. Comparison is done for two materials to verify best material for spring in suspension system.

Моделирование процесса теплоотдачи сверхпроводящих пленок в резистивном состоянии

The analysis of heat transfer in the contact-film-substrate system under conditions when the heat removal from the sample to the substrate is insufficient to ensure that the sample is not overheated. For low temperatures, a method is proposed for increasing the heat removal from thin-film samples by passing a high-density electric current through them. The property of an anomalously high thermal conductivity of copper at temperatures from 5 to 50 K was used as the main factor in enhancing heat removal. The heat equation for the film-substrate system was numerically solved under the condition of additional heat transfer to potential contacts. It has been shown that beryllium bronze contacts can provide efficient heat removal from samples of superconducting films in a resistive state under conditions of strong Joule heat release.