Deformation Of Wire Research Articles

Fabrication of a free-standing Pt micro-ring on an electrode chip as a small magnetic source

This paper describes a technique for fabricating a free-standing micro-ring on an electrode chip using a cutting and welding technique which utilizes Joule heating. A thin Pt wire with a diameter of about 650 nm was prepared on a Cu electrode chip, and mechanical deformation of the thin wire was induced by twisting it around an Ag core using a nano-manipulator. One end of the thin Pt wire was then welded by Joule heating onto another Pt wire that was located on the same electrode chip, but the Pt wire was electrically isolated from the thin Pt wire. The diameters of the micro-rings fabricated were 11 and 30 µm. The micro-ring supported by simple beams was then positioned above a permanent magnet, and the ring structure was deflected vertically by supplying a current to the ring. It was found from the experimental results that the deflection of the simply supported micro-ring was proportional to the amount of current that was supplied. The linear behavior of the deflection of the ring structure can be explained by the electromagnetic force between a micro-ring and a magnet which is proportional to the current supplied to the micro-ring.

Relation between Vibration of Wedge-Tool and Adhesion of Wire to Substrate during Ultrasonic Bonding

The present study relates the vibration behavior at the tip of wedge-tool during ultrasonic wire bonding with the state of adhesion at the interface of aluminum wire and silicon substrate. Cyclic change in amplitude by applying time of ultrasonic vibration is successfully detected by monitoring the vibration at the tip of wedge-tool. The spectral analysis indicates that local adhesion is not formed during increasing and high-amplitude stage of the cycle, while that is formed during decreasing and low-amplitude stage. By repeating such adhesion and separation, wire is deformed to a sufficient level to form a macroscopic bond. The ultrasonic vibration enhanced deformation of wire possibly occurs when the local adhesion is achieved. The amplitude of vibration affects the deformation rate.

Distribution of wire deformation within strands of wire ropes

Using ANSYS software, we developed a modeling program for several kinds of wire ropes with metal cores and built a geometric model for the 6×19 IWS wire rope. Through proper grid partitioning, a finite element model for calculating the deformation of wire rope was obtained. Completely constraining one end of the wire rope and applying an axial force to the other end, we established the boundary conditions for solving the model. In addition, we numerically simulated the stress and deformation of the wire, obtaining the deformation distribution of each wire within the wire rope under different laying directions. At the end, a tensile test of the 6×19 IWS wire rope was carried out and the results of simulation and experiment compared.

Nb$_{3}$Sn Wire Layout Optimization to Reduce Cabling Degradation

The next European dipole (NED) activity is aimed at the development of a large-aperture, high-field superconducting magnet relying on high-performances conductors. Part of the NED program is devoted to the mechanical study of a new generation of wires and to predict and describe their behavior under the severe loading conditions of the cabling process. A Finite Element modelization of wires was developed, allowing the wire behavior under simple uni-axial loads to be described. In this paper, the mechanical performances of different strand configurations are compared. The external diameter of the wire being fixed, several parameters are taken into account: the total number of sub-elements, the composition of the sub-elements, the local copper-to-non-copper ratio, the number of copper cells in the central region. The aim is to isolate the influence of each parameter on the wire deformations, trying to find an optimum design minimizing cabling damages.

In situ measurement of bond resistance varying with process parameters during ultrasonic wedge bonding

Interconnection joints are the signal and power carriers for chip-to-package, and their electrical property determines the whole component/device performances. With the process parameters ( P, F and t) varying, the bond resistance was in situ measured during ultrasonic bonding. The influence of the process parameters on the bond resistance was obvious. The measured bond resistance changed in the range from 64.5 mΩ to 72.5 mΩ with the ultrasonic power ( P) increasing. The maximum change of the single bond resistance was about 4 mΩ. The causation was analyzed in two aspects, evolution of the bond interface and deformation of the bond wire. Interfacial resistance ( R I) and deformation resistance ( R D) were two primary parts of the variance value.

Bonding mechanism of ultrasonic wedge bonding of copper wire on Au/Ni/Cu substrate

The ultrasonic wedge bonding with d25 μm copper wire was achieved on Au/Ni plated Cu substrate at ambient temperature. Ultrasonic wedge bonding mechanism was investigated by using SEM/EDX, pull test, shear test and microhardness test. The results show that the thinning of the Au layer occurs directly below the center of the bonding tool with the bonding power increasing. The interdiffusion between copper wire and Au metallization during the wedge bonding is assumed negligible, and the wedge bonding is achieved by wear action induced by ultrasonic vibration. The ultrasonic power contributes to enhance the deformation of copper wire due to ultrasonic softening effect which is then followed by the strain hardening of the copper wedge bonding.

Investigation of ultrasonic copper wire wedge bonding on Au/Ni plated Cu substrates at ambient temperature

Copper wire is attracting more and more attention in wire bonding technology due to its advantages in comparison with gold or aluminum wire. This paper presents an achievement of ultrasonic wedge bonding with 25 μm copper wire on Au/Ni plated Cu substrate at ambient temperature. A detailed investigation from the aspects of process optimization, bonding mechanism, interdiffusion, ultrasonic effects on microstructure and microhardness of the bonding materials were performed. The results show that it is possible to produce strong copper wire wedge bonds at room temperature, and the thinning of the Au layer was found directly below the center of the bonding tool with the bonding power increasing. Interdiffusion between copper wire and Au metallization during the wedge bonding at ambient temperature was assumed negligible. The wedge bonding was achieved by wear action induced by ultrasonic vibration. The ultrasonic power did contribute to enhancing deformation of the copper wire due to ultrasonic softening effect which was then followed by the strain hardening of the copper wedge bond, and the dynamic recovery or recrystallization of the copper wire caused by ultrasonic vibration during wedge bonding was also found.

An analysis of wire manufacture using the dieless drawing method

An experimental program of a novel wire manufacturing process known as dieless drawing has been conducted. The process has the capability to effect a reduction in the diameter of a wire without the use of conventional wire drawing dies. Reduction in diameter is achieved by heating the wire, which is mechanically loaded parallel to its longitudinal axis, to a temperature that initiates plastic deformation. Both mathematical and finite element (FE) modeling of the process have been undertaken. An analysis of the wire deformation is presented and discussed. The maximum reduction in diameter achieved, effect of drawing velocity, temperature, and uniformity of resulting wire diameter are investigated. The mechanics and operational features of the experimental machine manufactured to facilitate the experimental program of dieless drawing are described. The mathematical model presented can be used to describe the occurrence of deformation during the process. This model has been validated by experiments carried out on the wire drawing machine. The primary observation from the experimental program was that uniformity of wire diameter after dieless drawing decreased with an increase in reduction ratio. Results obtained from the experimental work confirm that a complicated interdependence of the process parameters exists during the dieless drawing process.

Superconducting properties and microstructure ofMgB2 wires synthesized with a low-temperature diffusion process

The compound MgB2 has a higher Tc value (39 K) and shorter decay time for induced radioactivity than Nb-based superconducting materials suchas Nb–Ti, Nb3Sn and Nb3Al.However, the Jc value of MgB2 wire is lower than Nb–Ti alloy superconducting wire, and furtherJc improvement is required for use in an advanced fusion reactor application. In order to improveJc properties, we tried to investigate a reconsideration of the heat treatment conditionthrough comparisons with low-temperature and long-time treatment, so-called‘low-temperature diffusion’. We confirmed that there was no reduction inTc valuescompared with conventional processes when heat treated at low temperatures and for longer times(450 °C for 200 h). Furthermore,core Jc values whenheat treated at 450 °C increased with extended heat treatment time, and then the maximum coreJc value wasfound to be over 1000 A mm−2 at 4.2 K under 5 T for the 200 h treatment sample and its value was higher than for conventionalsamples with SIC addition. From the results of SEM observation, 100 nm grain-sizedMgB2 microcrystals were densely formed in the wire core and these nanograin sizes of theMgB2 phase mightaffect the Jc improvement in the low and middle magnetic field regions. On the other hand, we tried tofabricate 100 m classed mono-cored Ta sheathed wire samples having stabilized Cu in orderto investigate the workability of the Ta-sheathed sample for possible use in an advancedfusion reactor application. We found that the wire deformation of 100 m classedwire without breaking was successful for this sample, and this result proved thegood workability and possibility of fusion application of metal Ta sheathed wire.

Planar elastica inside a curved tube with clearance

In this paper, we study the planar deformation of a thin elastic wire inside a tubular housing with clearance. The center line of the tube is assumed to be in the shape of a planar circular arc. The wire is under longitudinal compression at the ends. This mechanics problem can be found in the stent deployment procedure commonly adopted in treating patients with coronary artery diseases. The tube and the wire are meant to model the patient’s artery and the thin guidewire used in endovascular surgery, respectively. When the leading end of the guidewire encounters a blockage in the artery, the total length of the guidewire inside the artery varies as the wire undergoes bending deformation through the pushing at the other end. As a consequence, the leading end of the guidewire may not move forward the same distance that it is pushed in by the surgeon from the input end. It is also found that there exists a range of pushing force magnitude, in which one force magnitude may correspond to three different deformation patterns. Therefore, a deformation pattern jump may occur simply by adjusting the direction of the input force while holding the magnitude of the force constant. All these mechanics problems add more challenges to the surgeon’s delicate tasks in performing the surgery effectively.

On the influence of cutting speed limitation on the accuracy of wire-EDM corner-cutting

The wire electro-discharge machining (WEDM) process is widely used in the manufacturing of high-hardness steel precision tooling. Even though the process is characterised by its high accuracy level (sufficient even for micromachining applications), the development of enhanced generators that produce more energetic discharges yielding cutting speeds as high as 500 mm 2/min has resulted in stronger forces acting on the wire. These forces, together with the low rigidity of the wire, especially in the cutting of parts of high thickness, are responsible for wire deformation that has a direct influence on the accuracy of the part, mainly on wall-flatness and corners. In this work a study on the corner geometry generated by the successive cuts (roughing and finishing) is presented. Errors at different zones of the corner are identified and related to the material removed during each cut. Limitation of cutting speed allows a certain control on the amount of material actually removed by the wire. The influence of different aspects such as work thickness, corner radius and number of trim cuts is discussed. The main conclusion is that a corner accuracy optimisation procedure must consider the errors generated by the previous cuts.

The effects of friction and flexural rigidity of the archwire on canine movement in sliding mechanics: A numerical simulation with a 3-dimensional finite element method

The purposes of this article were to clarify the combined effect of friction and an archwire's flexural rigidity on canine movement in sliding mechanics, and to explain how to select a suitable archwire and force level for efficient bodily movement. A numerical simulation was carried out by using a 3-dimensional finite element method. As the frictional force decreased, both the net force acting on and the moving speed of the canine increased. The elastic deformation of the archwire increased, and the moving pattern of the canine changed from bodily movement to tipping, although there was no clearance between the archwire and the bracket slot. When a light wire was used, wire deformation increased, and the canine experienced greater tipping. These effects of friction and wire properties on canine movement (tipping and rotational angles) are combined by using a single parameter, EI/P, where EI is the flexural rigidity of the archwire, and P is the net force acting on the canine. A suitable combination of EI and P will cause canine bodily movement. The EI is determined from the archwire's size and material. We propose a method for estimating a suitable combination in this article.

RHQT JR Nb 3Al conductors developed for nuclear fusion devices

Three kinds of stabilized rapid-heating, quenching and transformation annealing (RHQT) Nb 3Al round wires have been developed for nuclear fusion devices; the Ag internally stabilized Nb matrix, the Cu internally stabilized Ta matrix and Cu ion-plated/electroplated wires. The critical current densities J c of Nb 3Al filaments are almost the same as the conventional Cu clad stabilized flat-wire, as long as the J c is optimized by mechanical deformation of wire after quenching but before the final transformation annealing. To demonstrate the applicability of RHQT Nb 3Al wire to nuclear fusion devices, we have trial manufactured a cable-in-conduit conductor (CICC) using the Ag internally stabilized round strands and confirmed the critical current of CICC to be nearly the same with the strain-free designed one.

はんだの変形にともなう起電力発生とその評価

Deformation of solder under uniaxial tensile and shear loads was studied using an electromotive force (EMF) method. The EMF started to increase as the solder wires deformed plastically and reached its maximum when necking and tensile fracture of the wires were observed. The maximum value of EMF increased linearly as the deformation speed increased. EMF generation was measured for the shear deformation of both solder wires and ball joints. The EMF maximum values for shear fracture of solder joints varied according to the fracture surface conditions. These results demonstrate that the EMF method is a useful technique for evaluating the deformation of solder.

NOVEL FBG SENSOR NET SYSTEM FOR REAL-TIME SHAPE DETECTION OF INTELLIGENT ENDOSCOPE

A novel slim FBG (Fiber Bragg grating) sensor device and its application in the real-time dynamic shape detection of colonoscope are presented. The sensing network device comprises a plurality of FBG sensors mounted on the body of a slim flexible wire. After the colonoscope is advanced in the body, the wire is pushed through the biopsy channel of the colonoscope. It bends with the curvature of the colonoscope. The FBG sensors capture deformation of the sensor wire, and reconstruct the shape of colonoscope. Experiments in the colon of a live swine have been done. Configuration of experimental system and experimental result are also given.

기하학 기술을 이용한 인레이/온레이의 외면 모델링

This paper presents a method for effectively modeling inlay/onlay prostheses restoring a tooth that are partially destroyed. An inlay/onlay is composed of internal surface adhering to an abutment, and external surface revealed to the outside sight. Internal surfaces are modeled using Minkowski sum expanding the grinded surface parts of abutments so that the internal surfaces can adhere to the abutments with closer contact. In modeling external surfaces, we exploit 3D mesh deformation techniques: DMFFD(direct manipulation free-form deformation)[19] and MWD(multiple wires deformation)[17] with three kinds of informations: standard teeth models, mesh data obtained by scanning a plaster cast of a patient`s tooth, FGP(functionally guided plane) measuring the occlusion of the patients`s teeth. The standard teeth models are used for building up the basic shapes of external surfaces, while the plaster fast and FGP data are used for reflecting the unique properties of adjacent md occlusal surfaces of the patients`s teeth, which are slightly different to each other but very important for correct functioning. With these informations as input data, the adjacent and occlusal surfaces are automatically generated as mesh data using the techniques of DMFFD and m, respectively. Our method was implemented so that inlay/onlay prostheses fan be designed more accurately by visualizing the generated mesh models with requirements by dentists.

Numerical simulation of canine retraction by sliding mechanics

Bone remodeling laws have been used to simulate the movement of a single tooth, but the calculations for simulating the movement of several teeth simultaneously are time-consuming. The purpose of this article is to discuss a method that allows the simulation of more complex tooth movements. A 3-dimensional finite element method was used to simulate the orthodontic tooth movement (retraction) of a maxillary canine by sliding mechanics and any associated movement of the anchor teeth. Absorption and apposition of the alveolar bone were produced in proportion to the stress of the periodontal ligament. In a reference case, the canine was retracted by a 2N force with 0.016-in square wire. The frictional coefficient between wire and bracket was 0.2. The movement of both the canine and the anchor teeth could be calculated with the elastic deformation of wire. The canine tipped during the initial unsteady state and then moved bodily during the steady state. It became upright when the orthodontic force was removed. The anchor teeth moved in the steady state and tipped in the mesial direction. The decrease in applied force by friction was about 70%. The tipping of the canine decreased when the wire size was increased or when the applied force was decreased. Simple assumptions were used in this calculation to simulate orthodontic tooth movements. The calculated results were reasonable in mechanical considerations. This method might enable one to estimate various tooth movements clinically. However, precise comparisons between calculated and clinical results, and the improvement of the calculation model, are left for a future study.

Review of Deformation Mechanisms, Texture, and Mechanical Anisotropy in Zirconium and Zirconium Base Alloys

Abstract The deformation systems in hexagonal close-packed (hcp) metals are not as symmetrically distributed as in cubic ones. Furthermore, because the primary slip systems are not as numerous and are limited to deformations in the <a> direction, twinning competes with slip in plastic deformation and can, depending on the deformation conditions, play an essential role. In order to explain the conditions in Zirconium and Zircaloy, the well-established relationships of hcp metals are discussed and so are their dependencies on the metal-specific parameters of the hexagonal structure. The interactions between deformation mechanisms and texture formation on the one side and deformation mechanisms and mechanical anisotropy on the other can be likewise transferred to other hcp metals, if one takes into account the differences in dependence of the metal-specific parameters. The low offer of slip systems, their asymmetrical distribution (prism slip in <a> directions and — under constraint — pyramidal slip in <c+a> directions) as well as the strict crystallographic orientation relationships of first and second order pyramidal twinning result in the formation of a strong deformation texture. By virtue of twinning, even small deformation rates lead to large lattice rotations, which change the orientation of the crystallites where all basal poles align in the direction of the compressive force. The fact that in Zirconium and Zirconium base alloys the preferred crystallographic orientation, which is spread in the transverse direction, is also retained as the final stable position is explained by <c + a> pyramidal slip. The decisive factor in texture development is the material flow, the degree of freedom of which is lowest for tube reducing as compared to sheet rolling and wire drawing processes. Therefore tube reducing (characterized by reductions in cross-section RA, wall thickness RW, and diameter RD) permits the most precise predictions of the operative forces and the resulting deformation mechanisms. Systematic investigations on the influence of the reduction parameters on the resulting preferred crystallographic orientation in Zircaloy tubing have shown that the determining factor controlling the texture development is the ratio RW1RD. For RW1RD > 1, the basal poles align preferentially in the radial direction. For RW1RD = 1, the basal poles are randomly distributed in the radial-tangential plane. For RW1RD < 1, the basal poles preferentially align in the tangential direction. The sheet texture is identical to the tube texture for RW1RD > 1, because in both examples the material flow is characterized by a preponderance of wall thickness reduction. The fiber texture of wire is identical to the texture of tubes for RW/RD = 1. One can visualize the wire deformation as corresponding to that of concentric tubes with different diameters to comply with tube reduction rates RW1RD = 1 under the condition of constant volume. Independent of the fabrication method for the cold-worked semi finished products, a first order prism pole aligns itself parallel to the direction of elongation. (During recrystallization, the basal poles do not change significantly. The basal planes, however, rotate continuously with increasing annealing temperature by ± 30° around their pole, so that in the final stable position, instead of a first order prism pole [cold deformation texture], a second order prism pole becomes parallel to the axial or rolling direction, respectively.) Knowing these dependencies, it is possible to tailor the texture of Zirconium base alloys tubing within the given limits to the requirements in nuclear application. For textured materials, on the other hand, the deformation mechanisms are also responsible for the strong anisotropy of the mechanical properties. This is discussed on the example of specially prepared Zircaloy tubes, which were machined out of a sufficiently thick Zircaloy plate with pronounced sheet texture. By this procedure, one obtains around the circumference of the tubing continuously changing preferred orientations of the basal poles with the extreme orientations possible in Zircaloy tubing. For the different uni- and multiaxial loading conditions applied, the theoretical predictions of the mechanical behavior agrees in any case with the experimental results. In nuclear application, the anisotropic behavior of biaxial loading conditions is represented by yield loci, creep loci, or burst loci according to the respective criteria yield stress, creep rate, or fracture stress. Depending on the texture and the loading conditions, an attempt is made to correlate the shape of the loci to the operative deformation mechanism. In this way, it is possible to find selection criteria for the desirable texture in Zircaloy cladding tubes.

上顎骨延長術におけるＲＥＤ ｓｙｓｔｅｍ固定装置の変形についての検討

Le Fort I osteotomy followed by distraction osteogenesis using the Rigid External Distraction (RED) system has been a useful method for facial and occlusal improvement of maxillary hypoplasia. Although an arch wire jointed to the stainless steel traction rod has been commonly fixed to the upper teeth in the RED system, some disadvantages, such as drifting of the teeth, have been pointed out in this method. Recently, the Leipzig retention plate, which is directly fixed to the maxilla, was reported and we also have been using this plate in our department. However, distraction osteogenesis using the RED system with these devices sometimes takes a long distraction time to get the expected amount of distraction because of the difference in the actual and expected amounts of maxillary advancement. One of the causes of this difference may be the deflection of the devices caused by the traction force.In this study, we examined the deformation of the devices caused by the traction force. The bending stiffness of the stainless steel rod of the teeth-fixing wire and the square rod of the Leipzig retention plate were determined by a three-point bending test. The elastic modulus of the stainless rod was lower than that of the square rod. On another examination of the deflection of the stainless steel rod and the square rod, which were bent into a U-shape, the deflection-load ratio of the stainless steel rod was higher than that of the square rod.We next studied the deformation of the teeth-fixing wire and Leipzig retention plate fixed to the dental arch model. Furthermore, the vertical rod and Halo frame of the RED system were fixed to the cranial model and their deformation was evaluated. We found that the teeth-fixing wire showed a greater deformation than the Leipzig retention plate on the dental arch model. The deformation of the vertical rod plus Halo frame was not observed when the traction force was less than 40N.These results indicated that the Leipzig retention plate was more useful than the teeth-fixing wire in the RED system because of the lower extent of deformation as well as the lack of teeth drifting. In addition, our results indicated that the deformation of the external fixation devices of the RED system could be negligible.

Tensile Deformation and Rotating-Bending Fatigue Properties of a Highelastic Thin Wire, a Superelastic Thin Wire, and a Superelastic Thin Tube of NiTi Alloys

The tensile deformation and rotating-bending fatigue properties of a highelastic thin wire, a superelastic thin wire and a superelastic thin tube, all made of NiTi alloys, were investigated experimentally. The results obtained are summarized as follows: (1) The stress-strain curve of the highelastic thin wire is approximately linear up to a strain of 4 percent with a stress of 1400 MPa and shows little dependency on temperature and strain rate; (2) The modulus of elasticity for the initial loading stage of both the highelastic wire and the superelastic tube is low, showing superior bending flexibility as is necessary for medical applications; (3) The slopes of the strain-life curves of the alloys are steep in the low-cycle fatigue region (the strain amplitude of the fatigue limit is in the region of 0.6–0.8 percent); and (4) In the tube, fatigue cracking initiates on the rougher inner surface, resulting in a shorter fatigue life than in the case of the wire.