Wire Material Research Articles

Three-part humeral head fractures treated with a definite construct of blocked threaded wires: finite element and parametric optimization analysis.

BackgroundMini open reduction and percutaneous fixation of three-part humeral head fracture with blocked threaded wires has demonstrated functional results similar to locking plates or intramedullary nails but with significantly lower major complication rate. In the context of three-part humeral head fractures, we performed a parametric optimization through a finite element analysis of a recently published construct to verify if the encouraging clinical results can be supported by a more rigorous investigation from a mechanical viewpoint.Materials and MethodsThe 2-dimensional geometry of a three-part proximal humerus fracture synthetized with a system of blocked threaded wires was created. Tension/bending/shear and compression load tests were simulated. A parametric optimization analysis was performed considering four design parameters (height of wire couples; wire material; interdistance between two wires). Eighteen simulations were carried out. Additional analyses were performed also considering a varying diameter of the external rod.ResultsFour points where the largest gap occurs and three points associated with the highest stress concentration were considered. As per the tension/bending/shear loading, a slight gap increase was observed in two different points (8.494 μm; 7.540 μm), while a slight decrease was detected along the greater tuberosity fracture line (1.445 μm). The maximum von Mises stress up to 64.4 MPa was achieved in the humeral head. As per the compression loading, the gap increased along the greater tuberosity fracture line (1.445 μm; 7.545μm); the maximum von Mises stress attains the value of 64.42 MPa. The smallest gap distance (15.37μm) and the lowest von Mises stress (51.51 MPa) were obtained in two different alternative constructs. The diameter of the external rod had no significant effect.ConclusionsThe studied construct is biomechanically valid; it only allows micromovements (one-thousandth of the characteristic humerus size) that are not able to cause humeral head rotation and translation. Furthermore, the construct generates acceptable pressure stresses on sensible areas of the fractured humeral head. Compared to the original construct, we propose to space the pair of horizontal wires for the great tuberosity by at least 1 cm.

Optimizing Fog Harps.

It has recently been demonstrated that harps harvest substantively more fog water than conventional mesh nets, but the optimal design for fog harps remains unknown. Here, we systematically vary key parameters of a scale-model fog harp, the wire material, wire pitch, and wire length, to find the optimal combination. We found stainless steel to not only be the best hydrophilic wire material but also nearly be as effective as Teflon-coated wires. The best choice for the wire pitch was coupled to the wire length, as the smallest pitch collected the most water for short harps but was hampered by tangling for taller harps. Accordingly, we use an elastocapillary wire tangling model to successfully predict the onset of tangling beyond a critical length for any given wire pitch. Combining what we learned, we achieved a water harvesting efficiency of 17% with an optimized stainless-steel harp, over three times higher than that of the current standard of a Raschel mesh. These results suggest that an optimal fog harp should feature high-tension, uncoated wires within a large aspect ratio frame to avoid tangling and promote efficient and reliable fog harvesting.

Analysis and Experimental Research on Vibration Reduction in Ship High-Temperature Pipeline Based on Long Coated Damping Structure

To reduce the vibration of a ship’s high-temperature pipeline, a long coated damping structure (LCDS) with entangled metallic wire material (EMWM) is proposed in this paper. The structural analysis of the long coated damping structure for pipelines is carried out. The theoretical analysis indicates that increasing the thickness of the damping layer in a particular range can improve the vibration attenuation effect of an LCDS. Additionally, experimental verification confirms this analysis after an experimental system for pipelines. From the results, it is observed that increasing the thickness of the coated layer can effectively improve the damping property of LCDS to a certain extent. The change of the coated length and the temperature has little effect on the vibration attenuation effect of an LCDS, indicating that the LCDS can work well in a high-temperature environment.

Mechanical Properties Test and Simulation Analysis of Glass Coated Amorphous Filaments

Taking the Co68.7Fe4Ni1B13Si11Mo2.3 glass-coated amorphous microwire as the research object, the mechanical properties of the amorphous wire were tested through biaxial tensile experiments, and the fracture deformation process of the amorphous wire was analyzed. Based on the experimental data, the finite element method was used The simulation software ABAQUS numerically simulates the tensile deformation of the amorphous wire, and the fracture relationship between the glass cladding layer and the core wire, and further reveals the tensile deformation fracture behavior of the amorphous wire was analyzed. The experimental results indicate that the fabricated microwires exhibit good tensile properties, and the maximum tensile breaking strength can reach 2918MPa; the fracture of the amorphous wire is a typical brittle fracture, and there is no obvious yield phenomenon. The tensile mechanics simulation results of the amorphous wire are consistent with the experimental results. The glass cladding layer breaks before the core wire, and the stress transfer effect in the amorphous wire is good. The model fracture is consistent with the fracture morphology of the amorphous wire. These results show that the amorphous wire exhibits good tensile properties and stress transmission capabilities, confirming the huge application potential of amorphous wire materials in sensor applications and functional composite materials.

Superconductivity in Al-Nb-Ti-V-Zr Multicomponent Alloy

The superconducting high-entropy alloys (HEAs) recently attract considerable attention due to their exciting properties, such as the robustness of superconductivity against atomic disorder and extremely high pressure. The well-studied crystal structure of superconducting HEAs is body-centered cubic (bcc) containing Nb, Ti, and Zr atoms. The same elements are contained in $$\mathrm {Al}_{5}\mathrm {Nb}_{24}\mathrm {Ti}_{40}\mathrm {V}_{5}\mathrm {Zr}_{26}$$ , which is a recently discovered bcc HEA and shows a gum-metal-like behavior after cold rolling. The gum metal is also an interesting system, exhibiting superelasticity and low Young’s modulus. If gum metals show superconductivity and can be used as a superconducting wire, the gum-metal HEA superconductors might be the next-generation superconducting wire materials. Aiming at a fundamental assessment of as-cast Al-Nb-Ti-V-Zr multicomponent alloys including $$\mathrm {Al}_{5}\mathrm {Nb}_{24}\mathrm {Ti}_{40}\mathrm {V}_{5}\mathrm {Zr}_{26}$$ , we have investigated the structural and superconducting properties of the alloys. All alloys investigated show the superconductivity, and the valence electron concentration dependence of the superconducting critical temperature is very close to those of typical superconducting bcc HEAs.

Friction behavior of the wire material Gummetal®.

ObjectivesGummetal® (Maruemu Works, Osaka, Japan), a new orthodontic wire material successfully used in clinical applications since 2006, is biocompatible and exhibits exceptionally high elasticity, nonlinear elastic behavior, plasticity and strength. Systematic comparisons of friction behavior are lacking; thus, the friction of Gummetal® in the binding modus was compared to commonly used low friction wires.Materials and methodsIn vivo tests were run with Gummetal®, CoCr (cobalt-chromium Elgiloy®, Rocky Mountain Orthodontics, Denver, CO, USA), β‑Ti (β-Titanium TMA®, Ormco, Orange, CA, USA), NiTi (nickel–titanium, NiTi-SE, Dentalline, Birkenfeld, Germany), and stainless steel (SS; Ref. 251-925, 3M Unitek, Monrovia, CA, USA) [dimensions: 0.014 inch (0.35 mm), 0.016 inch (0.40 mm), 0.016 × 0.022 inch (0.40 × 0.56 mm), and 0.019 × 0.025 inch (0.48 × 0.64 mm)—β-Ti not available in the dimension 0.014 inch]. These were combined with Discovery® (Dentaurum, Ispringen, Germany), Micro Sprint® (Forestadent, Pforzheim, Germany), Clarity™ (3M Unitek), and Inspire Ice™ (Ormco) and slots in the dimension 0.022 inch (0.56 mm) and, except for the 0.019 × 0.025 inch wires, in the dimension 0.018 inch (0.46 mm). They were ligated with a 0.010 inch (0.25 mm) steel ligature (Smile Dental, Ratingen, Germany). Brackets were angulated by applying a moment of force of 10 Nmm against the wire, which was pulled through the slot at 0.2 mm/s.ResultsIn 660 tests using 132 bracket–wire combinations, friction loss for Gummetal® was comparable to and, in a few combinations with Micro Sprint®, significantly lower (p < 0.05) than SS and CoCr. The friction for Gummetal® was significantly lower (p < 0.05) than NiTi, and β‑Ti. In some bracket–wire combinations, lower friction was found with round wires compared to rectangular wires, except for the combination with Inspire Ice™, which was higher but not significant. Slot size did not have a significant effect on friction in most combinations.ConclusionThe low friction associated with Gummetal® wires during arch-guided tooth movement will be a valuable addition to the armamentarium of orthodontists.

Experimental and Photographic Study of Surface Discharges on Different Polymeric Materials.(Dept.E)

A photographic investigation of the surface discharges on specimens of four polymeric materials is described. These materials are polystrene, polyvinyl chloride, teflon and prespex. Tests are performed under A. C. voltage on square specimens each of side length 10 cm and thickness of 0.5 mm to 6mm in non-uniform field consisting of wire and plane electrodes. The wire electrode has diameters ranged from 0.3 mm to 6 mm. The inception voltage of the surface discharges is found to be dependent on both factors namely the wire diameter and material thickness. The relationship between this voltage and either of the two factors is proposed to be in the form of a straight line formula. The surface discharges are recorded by a photographic camera using the four above-mentioned polymeric materials. The inception voltage is determined by means of an oscilloscope. Some selected close-up photographs are given here as example to demonstrate the nature of the surface discharges. The oscilloscope current traces of these discharges are also recorded by the camera and some of the reproduced photographs are also given for different wire diameters and material thickness.

Experimental Investigation of a Cryogenically Cooled Oxygen-mist Near-dry Wire-cut Electrical Discharge Machining Process

In this paper, a novel method of cryogenically cooled (low-temperature nitrogen gas) wire tool is used during the oxygen-mist near-dry wire-cut electrical discharge machining (NDWEDM) process to cut Inconel 718 alloy material. The current, pulse-width, pulse-interval, and flow rate are the controllable variables for response characteristics, such as the material removal rate (MRR) and wire wear ratio (WWR). The Box-Behnken method is applied to design the experiments to collect the observations from experiments. The mathematical models for each response were developed using significant individual, interaction, and quadratic terms by the sequential sum of the square test. The response surfaces were developed. It was revealed from the analysis that 52.92 % of current, 24.63 % of Pulse-width, 12.81 % of pulse- interval and 5.75 % of flow rate contributed to MRR, while 14.89 % of current, 9.75 % of pulse-width, 62.20 % of pulse-interval, and 5.44 % of flow rate contributed to WWR. The pulse-width has more contribution on MRR due to the long period of spark between the wire and work materials. It was also observed that the pulse-interval has more effect on WWR due to the more ideal period (high spark-pause-time) between two consecutive high-temperature sparks in the wire tool. The wear of the wire tool has been analysed using scanning electron microscopy (SEM) photographs. The desirability principles were first applied to obtain multi-objective solutions with a combination of process parameters to achieve the optimal values of both responses. The predicted combination of results has been validated by data that were collected from confirmation experiments.

Experimental Investigation of a Cryogenically Cooled Oxygen-mist Near-dry Wire-cut Electrical Discharge Machining Process

In this paper, a novel method of cryogenically cooled (low-temperature nitrogen gas) wire tool is used during the oxygen-mist near-dry wire-cut electrical discharge machining (NDWEDM) process to cut Inconel 718 alloy material. The current, pulse-width, pulse-interval, and flow rate are the controllable variables for response characteristics, such as the material removal rate (MRR) and wire wear ratio (WWR). The Box-Behnken method is applied to design the experiments to collect the observations from experiments. The mathematical models for each response were developed using significant individual, interaction, and quadratic terms by the sequential sum of the square test. The response surfaces were developed. It was revealed from the analysis that 52.92 % of current, 24.63 % of Pulse-width, 12.81 % of pulse- interval and 5.75 % of flow rate contributed to MRR, while 14.89 % of current, 9.75 % of pulse-width, 62.20 % of pulse-interval, and 5.44 % of flow rate contributed to WWR. The pulse-width has more contribution on MRR due to the long period of spark between the wire and work materials. It was also observed that the pulse-interval has more effect on WWR due to the more ideal period (high spark-pause-time) between two consecutive high-temperature sparks in the wire tool. The wear of the wire tool has been analysed using scanning electron microscopy (SEM) photographs. The desirability principles were first applied to obtain multi-objective solutions with a combination of process parameters to achieve the optimal values of both responses. The predicted combination of results has been validated by data that were collected from confirmation experiments.

Mechanical force system of double key loop with finite element analysis

BackgroundThe mechanics of double key loop (DKL) are not well defined, and this finite element study was designed to explore its force system.MethodsA simplified 3-dimensional finite element model of single and double key loops with an archwire between the lateral incisor and second premolar was established in Ansys Workbench 17.0. Activation in Type-1 (retraction at the distal end), Type-2 (retraction at the distal key) and Type-3 (Type-2 plus ligation between keys) was simulated. The vertical force, load/deflection ratio and moment/force ratio of stainless-steel and titanium-molybdenum alloy (TMA) loops were calculated and compared.ResultsThe double key loop generated approximately 40% of the force of a single key loop. Type-2 loading of DKL showed a higher L/D ratio than Type-1 loading with a similar M/F ratio. Type-3 loading of DKL showed the highest M/F ratio with a similar L/D ratio as single key loop. The M/F ratio in Type-3 loading increased with the decreasing of retraction force. The DKL of TMA produced approximately 40% of the force and moment compared with those of SS in all loading types. When activated at equal distances below 1 mm, the M/F ratios of SS and TMA DKL with equal preactivation angles were almost the same.ConclusionThe M/F ratio on anterior teeth increases with the preactivation angle and deactivation of DKL. The M/F ratio at a certain distance of activation mainly depends on the preactivation angle instead of the wire material. TMA is recommended as a substitute for SS in DKL for a lower magnitude of force.

Pulsed Laser Deposition of Ti-Based MAX Compounds for Next-Generation Wiring Technology

Semiconductor wiring technology with a width of 10 nm or less is going in order to realize high performance and high integration of large-scale integrated circuits. Copper is currently used as the main wiring material, however, a barrier layer of TiN is necessary due to high diffusivity of Cu into Si or SiO2. In addition, the resistivity of TiN is ten times higher than that of Cu, which results in a drastic increase with decreasing line width less than 10 nm. Therefore, the development of a barrier layer free wiring material to replace copper should be necessary.The MAX compounds (M: transition metal element, A: A-group element, X: either carbon or nitrogen) is one of the promising candidates for next generation wiring technology. The stoichiometry of MAX compounds is Mn+1AXn (n = 1~3), and exhibits the properties of both ceramics and metals, and some of the compounds have a low volume resistivity as 10 μΩcm. In this study, pulsed laser deposition of TiSiN and TiGeN were carried out and physical and electrical properties were evaluated.Targets (TiN : Ti : Ge or Si = 3 : 1 : 1) was bought from TOSHIMA Manufacturing. Al2O3 (001) and 1-μm thickness thermal oxide on Si(001) was used as substrate. Substrate temperature was either room temperature or 600℃. N2 was introduced during deposition. Repetition frequency was fixed at 8 Hz, and laser energy was changed from 25 mJ to 75 mJ. Table 1 and 2 show deposition condition for TiGeN and TiSiN, respectively. X-Ray Diffraction and X-Ray Photoelectron Spectroscopy were used to evaluate the crystallographic structure and composition ratio, respectively. Film thickness was measured by using surface profiler. Electronic properties were measured by four point probe method. Figure 1 shows XRD pattern of TiGeN film deposited on Al2O3 substrate. When TiGeN was deposited at 600℃ and B.P., peaks ascribed to Ge(111), TiN(111) and TiN(200) were observed. TiN(111) peak position 36.85° from TiGeN is 0.04° higher than that from TiN (111) (36.81°, Card No. 00-006-0642), which suggests that lattice parameter decreased from 2.440 Å to 2.437Å. On the other hand, the peak intensity of TiN(200) from TiGeN deposited at 600℃ becomes clear by introducing N2 to 2.0 Pa. TiN(200) peak positions from TiGeN at 600℃ with 0.02 Pa and 2.0 Pa were 39.30° and 39.35°, respectively, the difference from TiN(200) (42.61°, Card No. 00-006-0642) were 3.31° and 3.26°. This suggests that lattice parameter becomes larger from 2.120 Å, to 2.291 (0.02 Pa) or 2.288 Å (2.0 Pa), respectively. One possible reason could be the incorporation fo Ge into TiN lattice. Figure 1

Conducting Dermatological Operations in Patients Who Have Previously Undergone Cardiac Surgery

Thoracic surgical procedures and the use of cardiac devices such as pacemakers are becoming increasingly common in the population. Therefore, dermatologists may be more likely to encounter previously implanted or discarded surgical material during a dermatological operation on the chest wall. A basic understanding of the types of wires and tunneling paths used in such procedures is essential to accurately predict the presence of these wires and effectively manage any chance encounters.&#x0D; Dermatologists should be aware that temporary epicardial pacemaker electrodes and pacemaker electrodes often remain in the chest wall of many patients. All patients with a history of cardiac surgery should be asked about the possible presence of temporary epicardial electrodes in their body, and if such materials are found during the operation, it is necessary to immediately stop the procedure and do not undertake further manipulations with them until the material from which it is made is determined.&#x0D; Specialists in cardiology and cardiothoracic surgery need to document any abandoned wire in the patient's list of problems and inform the patient about the abandoned wire so that he or she can be an important source of clinical information.&#x0D; Trying to pull out the remaining pacemaker electrodes is a serious risk, so dermatologist surgeons should not attempt it under any circumstances. When detecting wire material, it is necessary to determine the type and location of the material before any manipulation or pulling attempts. Once it is established that this is a non-functional, abandoned wire, it is necessary to apply the correct technique for removing it, which consists in gently pulling and securing the wire at the exit point. Accurate identification of the material is required in order not to interfere with the operation of the active device and not to abandon the operation unnecessarily.&#x0D; The aim of the work is to consider the implementation of dermatological operations in patients who have previously undergone cardiac surgery.

Maximum Entropy Principle Underlies Wiring Length Distribution in Brain Networks.

A brain network comprises a substantial amount of short-range connections with an admixture of long-range connections. The portion of long-range connections in brain networks is observed to be quantitatively dissimilar across species. It is hypothesized that the length of connections is constrained by the spatial embedding of brain networks, yet fundamental principles that underlie the wiring length distribution remain unclear. By quantifying the structural diversity of a brain network using Shannon's entropy, here we show that the wiring length distribution across multiple species-including Drosophila, mouse, macaque, human, and C. elegans-follows the maximum entropy principle (MAP) under the constraints of limited wiring material and the spatial locations of brain areas or neurons. In addition, by considering stochastic axonal growth, we propose a network formation process capable of reproducing wiring length distributions of the 5 species, thereby implementing MAP in a biologically plausible manner. We further develop a generative model incorporating MAP, and show that, for the 5 species, the generated network exhibits high similarity to the real network. Our work indicates that the brain connectivity evolves to be structurally diversified by maximizing entropy to support efficient interareal communication, providing a potential organizational principle of brain networks.

The Effect of the Design of the Nozzle System of Electric Arc Metallizing Devices on the Conditions of Spraying Wire Materials

The Effect of the Design of the Nozzle System of Electric Arc Metallizing Devices on the Conditions of Spraying Wire Materials

Study of Part Restoration Modes Using Electrocontact Welding with Gauze Filler Materials

This article proves the advantage of gauze compared to the wire, tape, and powder materials as a filler material for electro contact welding. The gauze as a tape material consisting of wires has the advantages of wire (high adhesive strength and high fatigue life) and the tape advantages (high producibility, ease of use). The paper presents the coating study methods and results using gauze welding and the effect of this coating on the adhesive strength depending on electro contact welding modes, material and gauze parameters, residual stresses in coatings, and coating wear-resistance. During electro contact welding in rational modes, the woven gauze adhesive strength is 41% higher than the steel tape. When analyzing residual stress as a relation of the effective stress to the material yield strength of the sample or coating, it was found that residual stresses have a smaller effect in the woven gauze coating compared to the tape made of steel 45. A stainless steel woven gauze coating and a steel tape coating made from steel 45 are equal in wear resistance. Thus, a metal gauze can be used as filler material during electro contact welding on the surface of worn parts instead of steel tape made from a similar grade of steel applied to the worn parts' surface.

Testing the State of Internal Load and Strength of the Facade Mesh Wire Subjected to the Corrugation Process

Abstract The article presents an example of a structural solution of a mesh facade installed on a public building. The types of loads that can affect the structure of such a mesh have been characterized. The course of the wire shaping process used to produce the described mesh was reported. A finite element method (FEM) model was developed to simulate mechanical phenomena occurring during the technological process of crimping stainless-steel wire. Material model parameters have been defined. The developed model was verified in production conditions. Relations between wire-forming loads and tensile limit loads, as well as the distribution of equivalent tensile stress forced by the crimping process and internal stresses after crimping, were determined. The description of the technological process was presented in a form of a graph. The work contains the results of strength tests of wire materials and shaping tools.

Study influence factors of the spraying process on the properties of electric arc spraying coatings

The paper considers possibilities to increase the wear resistance, corrosion resistance, and service life for parts machines and mechanisms via their hardening and renovating using electric arc coatings characterized by high density, adhesion strength, and micro hardness thanks to activation of the spraying process. Also, the possibility of controlling the properties of restored surfaces owing to choice of the related equipment with required structure and characteristics in order to prolong the service life of machinery parts is shown. The right choice of equipment for spraying makes it possible to increase the speed and temperature of the spraying gas and particles, reduce the droplet diameter, increase the density and reduce the oxidation of coatings. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated. The possibility of controlling the properties of surfaces owing to choice with required characteristics electric arc coatings is shown. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated. The use of coatings makes it possible to increase the wear and corrosion resistance of working surfaces of machine parts and mechanisms, in particular ship parts, and so to reduce the costs of alloyed steels and alloys. The coatings application is associated with implementation of a fundamentally new approach, according to which the strength and carrying capacity of a part is provided by its basic material, whereas the resistance to corrosion, wear, and other factors may be increased via using hardening protective coatings. There are many alternative methods for producing coatings, from which it is advisable to choose an optimal, easy to implement, and inexpensive one. Of the variety of methods for hardening coating deposition, the most common technologies used to restore and improve the performance properties of parts are gas-thermal spraying techniques, among which the cheapest and simplest method is electric arc spraying (EAS), whose current improvement is aimed at modifying and activating the spraying process. Such combined technologies do not require additional expensive equipment and operations, which predetermines a reduction in the cost of hardening processes.

Research on the variable mechanical properties and application in vibration control of soft magnetic entangled metallic wire material

A novel soft magnetic entangled metallic wire material (SM-EMWM) is investigated in this article, which is manufactured using the magnetoelectric-sensitive soft magnetic wires. The mechanical properties (tangent modulus, loss factor) of SM-EMWM can be tunable in the magnetic field rapidly and reversibly, and thus can be applied to vibration control systems. The quasi-static and dynamic tests in different magnetic fields were carried out, and the results show that the tangent modulus of SM-EMWM samples in a magnetic field of 500 mT can increase 2–7 times on average compared with no magnetic field condition, while the loss factor can be improved above 50%. Therefore, with the enhancement of the intensity of the magnetic field, the resonant frequency of the system with SM-EMWM increases, the peak value of response curves decreases dramatically as well. Based on the results of dynamic tests, one suitable adaptive vibration control strategy was developed and used in the tests to avoid the resonant frequency of the system, by controlling the magnetic field condition appropriately. The results show that the peak vibration transmissibility of the controlled SM-EMWM system decreases over 50%, which reveals the excellent application prospect of the SM-EMWM for the active or semi-active control vibration control in mechanical structures.

Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization

Ultrasonic wire bonding is a solid-state joining process, used in the electronics industry to form electrical connections, e.g. to connect electrical terminals within semiconductor modules. Many process parameters affect the bond strength, such like the bond normal force, ultrasonic power, wire material and bonding frequency. Today, process design, development, and optimization is most likely based on the knowledge of process engineers and is mainly performed by experimental testing. In this contribution, a newly developed simulation tool is presented, to reduce time and costs and efficiently determine optimized process parameter. Based on a co-simulation of MATLAB and ANSYS, the different physical phenomena of the wire bonding process are considered using finite element simulation for the complex plastic deformation of the wire and reduced order models for the transient dynamics of the transducer, wire, substrate and bond formation. The model parameters such as the coefficients of friction between bond tool and wire and between wire and substrate were determined for aluminium and copper wire in experiments with a test rig specially developed for the requirements of heavy wire bonding. To reduce simulation time, for the finite element simulation a restart analysis and high performance computing is utilized. Detailed analysis of the bond formation showed, that the normal pressure distribution in the contact between wire and substrate has high impact on bond formation and distribution of welded areas in the contact area.

The action-integral and energy to explode short gold wires in ambient air

This paper is about electrically induced explosions of short (1 mm) and thin (38 μm diameter) gold bridgewires in ambient air and contrasts this behavior with that observed for longer wires in a vacuum used in applications such as Z-pinch systems. The action-integral (the time integral of the wire current squared) and energy-to-burst are measured using high current discharge systems. It is found that in contrast to some reports, the action-integral to burst is not a constant for a specific wire geometry and material but, instead, is a function of the rate of current change in the wire around the time of burst and the related metric of the current flux at burst. Furthermore, it is found that the accuracy of the constant action-integral to burst approximation is dependent on the discharge system used. Short gold wires such as these have relevancy to exploding bridgewire detonators.