Deformation Of Wire Research Articles

Failure analysis of steel wire rope used in overhead crane system

After 53 days of service of a steel wire rope in a 12-ton overhead crane system a catastrophic failure has occurred during operation. The wire rope was inspected and sectioned in both sides of the failure. To determine the reason of the failure, samples from the damaged rope were analyzed using visual inspection, stereoscopic analysis, scanning electron microscopy and microhardness tests. Information was collected from worksheets to correlate operation conditions and possible failure causes.After first inspections of the failure zones in the steel wire rope, damage was apparently not caused by fatigue. After stereoscopic and microscopic observations, a mechanism of failure was determinate and proposed. In the initial stage, there was a localized plastic deformation and wear of individual wires accelerating stress concentration and finally fatigue. All these events were correlated with the hoist system operation and installation conditions.

Friction, wear and residual strength properties of steel wire rope with different corrosion types

Surface wear and corrosion affect the service performance of steel wire rope. They usually appear alternately and interact. In this paper, the friction and wear properties of wire ropes with different corrosion types were investigated. Then, the interactions of the corrosion and wear on the residual strength of the rope samples were analysed. The results show that the corrosion had a strong influence on the coefficient of friction (COF) and temperature rise of the wire rope. Additionally, surface corrosion reduced the anti-wear properties and fatigue resistance of the rope. The effect of sulfuric acid corrosion was the most obvious, followed by that of sea-water and fresh water. The maximum breaking force of the wire rope with sulfuric acid corrosion decreased rapidly with the wear time, from approximately 49.9 kN–41.5 kN. Furthermore, under tensile load, the plastic deformation of the rope wires was closely related to the surface wear and corrosion condition. This study can provide basic data for the safe use and maintenance of steel wire rope.

Image-Based Displacements Analysis and Computational Blood Dynamics after Endovascular Aneurysm Repair

To examine intraheartbeat displacements (IHD) and geometrical changes of endografts for abdominal aortic aneurysm repair over the course of years, defined as follow-up displacements (FUD), and to correlate them with computational fluid dynamics (CFD). Despite the widespread use of endovascular aneurysm repair (EVAR), we still know little about endograft behavior after deployment. Two cases, treated with either expanded polytetrafluoroethylene on a nitinol stent frame (PI) or with woven polyester fabric sutured to a stainless-steel Z stent skeleton (PII), were submitted to dynamic computed tomography angiography at 1, 12, and 60months after implantation. After segmentation, IHD were computed as displacements of the reconstructed surface with respect to the diastolic instant. Similarly, FUD were studied using imaging techniques that align temporal successive segmentations. In addition, numerical simulations for blood dynamics were performed to compute viscous forces, specifically wall shear stress and time-averaged wall shear stress (TAWSS). IHD analysis showed slight translations without deformation for the PI endograft with respect to the stiffer stainless-steel endograft behavior of PII. FUD showed in PI motion of the metallic struts mainly focused on the distal main body of the endograft and in the zone overlapping with iliac branches. In PII, we observed a huge FUD in the middle and inferior-anterior regions of the main body. CFD analysis revealed changes of velocity patterns associated with remodeling of the iliac zone for PI and of the main body region for PII, where flow impinges the lumen wall and progressively induces deformation of the endograft wires. Measurement of TAWSS demonstrated flow disturbances in the enlarged region correlated with displacement analysis. Image-based displacement analysis associated with CFD enabled very subtle evaluations of endograft behavior on different temporal scales. This kind of study could be helpful both for physicians, forecasting evolution during the life span of the endograft, and manufacturers, giving them useful information about endograft implant performance and design.

Cross-sectional structure, microstructure and mechanical property evolutions of brass cladding pure copper stranded wire composite during drawing

Abstract A solid/liquid continuous casting and composite technology was used to produce d8.5 mm brass cladding pure copper stranded wire composite billet and the composite billet was then drawn. The results showed that the composite billet had good surface quality, metallurgical bonding interface between brass and pure copper as well as elongation of 53.1%. Synergistic deformation degree between pure copper wire and brass cladding layer was high during drawing. With an increase of the total deformation amount, the plastic deformation of the pure copper wire reduced triangular arc gaps between the pure copper wires and the triangular arc gaps were fully filled at 50%. When the total deformation amount was increased to 63%, dislocation cells and microbands successively formed in the pure copper wire. In the brass cladding layer, planar dislocation networks, twins and shear bands formed successively, and the main deformation mechanisms were dislocation sliding, twinning and shear deformation. The tensile strength increased from 240 MPa of the composite billet to 519 MPa of the one with the deformation amount of 63%, but the elongation decreased from 53.1% to 3.2%. A process of solid/liquid continuous casting and composite forming→drawing can work as a new compact method to produce brass cladding pure copper stranded wire composite as railway through grounding wire.

TEM analysis of deformation bands created by tensile deformation of superelastic NiTi wires

Deformation processes derived from martensitic transformation in shape memory alloys are theoretically fully recoverable in a complete thermomechanical loading cycle across transformation range and do not leave any lattice defects in the microstructure. In reality, this is rarely the case in NiTi, since plastic deformation tends to accompany the martensitic transformation, particularly if it proceeds under large stress. Lattice defects observed in the microstructure of deformed NiTi wires (slip dislocations and deformation bands) attract the attention of researchers, since they are linked to unrecovered strains and play significant role in functional fatigue, shape setting or two-way shape memory effect. In this work, we present an experimental approach allowing for analysis of deformation bands in deformed NiTi consisting in: i) preparation of superelastic NiTi wires with recrystallized, small grained microstructure, ii) subjecting these wires to desired tensile test (e.g. superelastic or shape memory cycle) and iii) characterizing the deformation bands in TEM using selected area electron diffraction combined with dark field imaging following simple rules described in this work. If the deformed microstructure becomes too complex due to the high density and small size of deformation bands, ASTAR orientation mapping can be beneficially applied to reveal the refinement of the microstructure through the introduction of deformation bands.

Study of Wire Deformation Characterization and Size Effects during the Micro-Flat-Rolling Process

A comprehensive research on the flat rolling deformation characterization of microwire has been conducted systematically through finite element simulation and testified by the results from the experimental analysis. The obtained results are compared in terms of lateral spread, geometrical characteristic, contact area width and surface roughness considering the effects of pass reduction and initial wire diameter. The size effect has been identified and surface layer modeling has been set up based on surface grain share and grain size distribution. The numerical method combined with varied flow stress has been verified by experimental value with a maximum difference of 3.7% for the 1.5 mm wire. With the increase of the height reduction, the curvature radius is decreased while the lateral spread and contact area width are increased. Surface roughness evolution in the range of 0.52–0.85 µm for the rolled wire has also been investigated.

Cyclic-bending deformation of aluminum rectangular wire with preferred orientation 〈111〉 parallel to drawing direction

Cyclic-bending deformation of aluminum rectangular wire with preferred orientation 〈111〉 parallel to drawing direction

On Deformation Behaviour of Polycrystalline Iridium at Room Temperature

Deformation and fracture behaviour of cold drawing iridium wire under tension at room temperature is examined. High purity polycrystalline iridium was manufactured using pyrometallurgical technology. During the initial stage of cold rolling, iridium wire has its usual grain structure and exhibits brittle deformation behaviour: poor plasticity and brittle transgranular fracture (BTF). However, the wire begins demonstrating high plasticity including necking in spite of the brittle fracture mode when the lamellar structure has been formed in iridium during cold drawing.

Specific forward/reverse latent heat and martensite fraction measurement during superelastic deformation of nanostructured NiTi wires

This study analyses the thermomechanical tensile behaviour of a cold drawn Ti-50.9at.%Ni wire submitted to heat treatment at 598 K for 30 min, which is below the recrystallization temperature (623 K). Such low temperature heat treatment induces a superelastic loop without a stress “plateau”. However, the absence or weakness of peaks on its differential scanning calorimetry prevents the determination of specific latent heat. This is a common effect of nanostructured materials such as superelastic wires. A method using strain and temperature field measurements was developed and used to determine thermal power and thermal energy during superelastic tensile tests through a heat balance. From these results and using a thermodynamic approach, forward and reverse specific latent heat and the martensite fraction are estimated as a function of strain and stress.

Підвищення довговічності роликів-електродів при електроконтактному наплавленні деталей мобільної сільськогосподарської та автотранспортної техніки

During the operation of mobile agricultural and motor vehicles, their connections and parts are activated. This leads to a decrease in traction power, operating speed, quality and productivity when performing technological operations. Repair costs are constantly rising, so the question of finding inexpensive technologies for the restoration of worn parts is relevant. Such technologies include electro-contact surfacing. One of the reasons that constrains the widespread use of the method of electrocontact surfacing is the low stability of the electrode roller. Currently, little research has been conducted to study the wear of the electrode rollers and increase their wear resistance. The research on search of ways of increase of durability of rollers-electrodes at electrocontact surfacing is carried out. The operating conditions of the electrode rollers and their operation, the strength of the welded joint when using a tool with different degrees of operation were considered. The operation of the roller-electrode during electro-contact surfacing has a negative effect on the strength of the welded joint of the metal coating with the base due to the reduction of deformation of the filler wire. The results of tests for operation show that a significant reduction in the quality of the welded joint occurs when using electrodes made of hot-rolled copper after 1.5...2 hours of operation. It is not possible to fully compensate for the negative impact of the electrode operation on the quality of the welded joint by adjusting the technological modes of surfacing. This indicates the need for 2 - 3 times the replacement of such tools, after grooving their working surfaces on a lathe. Developed recommendations for the choice of sizes of rollers-electrodes used in electro-contact surfacing of parts of mobile agricultural and transport equipment.

Локальные дефекты в протяженных пластичных аморфных проводах, изготовленных методом Улитовского – Тейлора

Typical local defects were identified in extended ductile amorphous Co-based alloy wires, having 50 – 110 µm in diameter, obtained by Ulitovsky – Taylor in a continuous process of drawing a jet of melt in a glass shell. The studies found that gas pores and necks are local defects of glass-coated wires. The paper analyses the impact of the dissolved in the metal melt gas and glass-coating stress on the drawing process stability and the geometric parameters of the wire. The formation of hidden pores is due to gas expelling and redistribution of gas following the melt stream solidification. It is noted that gas porosity would not result in spontaneous breaks and changes in wire geometry. The characteristic form of a brittle rupture of an amorphous wire was observed upon fracture by bending in the region of gas porosity. It was in the studies revealing that amorphous wire neck formation was caused by high temperature transverse ring cracking of the glass-coating in contact with quenching liquid. Elastic deformation of amorphous wire in the vicinity of neck flows through the mechanism of formation and sliding transverse shear band. It is noted that the longitudinal destruction of the glass shell does not affect the geometric parameters of the amorphous wire. The procedures for local defects eliminating while producing ductile amorphous wires and the possible prospects for the variable diameter wires manufacturing are proposed.

Experimental and Numerical Studies on the Deformation of a Flexible Wire in an Injection Moulding Process

The application of thermoplastic materials is state of the art due to their fast cycle times in production and large freedom of shaping. To enhance the performance and functionality, additional materials or elements are embedded into the bulk material. While typically fibres are added for mechanical reinforcement, recent research also focusses on the integration of conductor wires to integrate electrical functions. During the manufacturing process, the interaction with the thermoplastic melt can lead to breakage or undesired deformation of the flexible elements respectively wires. For a proper process and component design, this local fluid-structure-interaction must be understood and considered. There are different numerical approaches to meet this challenge. In the present work, the suitability of established modelling techniques and solvers is evaluated and compared with experimental investigations. For this purpose, solid flexible wires are overmoulded with polypropylene using an injection moulding testing set-up. In the experimental investigations, the deflection of the wire is evaluated for different process settings. For the numerical simulations, solvers from ABAQUS and Moldflow including the Wire Sweep Module and the Core Shift Module are used. The comparison of the simulations and the experiments shows, that the different solver’s results clearly deviate from each other and the experiment depending on the wire length. While some approaches seem to be very promising, it can be concluded that the longer the wire, the worse the simulation quality.

Prediction of Effective Strain Distribution in Two-Pass Drawn Wire.

In the multi-pass wire drawing process, the diameter of a wire is decreased by continuously passing it through progressively smaller drawing dies. Although the deformation depends on the process variables, in most wire drawing processes, the wire deformation is concentrated on the surface by its direct contact with the drawing dies, causing a nonlinear distribution of radial direction effective strain from the center to the surface. In this study, a new model for predicting this effective strain in two-pass drawn wire was derived based on the upper bound method, and a finite element analysis and drawing experiment were conducted to validate its effectiveness. The proposed model offers a promising approach to determining and thus controlling the strain in multi-pass drawn wire.

B2 ⇒ B19′ ⇒ B2T Martensitic Transformation as a Mechanism of Plastic Deformation of NiTi

Deformation of superelastic NiTi wire with tailored microstructure was investigated in tensile loading–unloading tests up to the end of the stress plateau in wide temperature range from room temperature up to 200 °C. Lattice defects left in the microstructure of deformed wires were investigated by transmission electron microscopy. Tensile deformation is localized up to the highest test temperatures, even if practically no martensite phase exists in the wire at the end of the stress plateau. In tensile tests at elevated temperatures around 100 °C, at which the upper plateau stress approaches the yield stress for plastic deformation of martensite, upper plateau strains become unusually long, transformation strains become unrecoverable and deformation bands containing {114} austenite twins appear in the microstructure of deformed wires. These observations were rationalized by assuming activity of B2 ⇒ B19′ ⇒ B2T martensitic transformation into the austenite twins representing a new mechanism of plastic deformation of NiTi, additional to the dislocation slip in austenite and/or martensite. It is claimed that this transformation becomes activated in any thermomechanical load in which the oriented B19′ martensite is exposed to high stress at high temperatures, as e.g., during shape setting or actuator cycling at high applied stress.

Preparation of 3DGP dense zirconia parts by two-step method:staggered stacking method and printing wire deformation

A new process, staggered stacking method of printing wires and printing wire deformation by 3D gel-printing, to prepare ZrO2 dense parts was used in this study. In order to reduce the gap between adjacent printing wires, a new type of stacking method-staggered stacking is proposed. The density of sintered parts prepared by staggered stacking method is about 88%. In order to eliminate the gap between the adjacent cylindrical printing lines, according to printing wire deformation and then adjusting the parameters, the printing head was used as a scraper to fill the gaps. The relative density of sintered body prepared by staggered stacking method of printing wires and printing wire deformation in this study is 98.86%, and the three-point bending strength of the parts is 496 ± 20 MPa.

Recoverability of large strains and deformation twinning in martensite during tensile deformation of NiTi shape memory alloy polycrystals

Superelastic NiTi wires were deformed in tension up to gradually increasing total strains at various temperatures, recoverable strains were evaluated and lattice defects left in the microstructure of deformed wires were analyzed by TEM. The recoverable strains evaluated in tensile tests: i) are surprisingly large - exceed 10% strain at low temperatures T ≤ 20 °C, ii) are not significantly restricted by large plastic deformation up to 55% at low temperatures, iii) display local maxima in dependence on total strain in tensile tests at low temperatures, iv) decrease with increasing test temperatures and iv) increase with increasing total strain in tensile tests at high temperatures T ≥ 50 °C. Besides slip dislocations, key lattice defects created by the tensile deformation beyond the martensite yield point are deformation bands containing {114} austenite twins or R-phase. No other austenite twins were found statistically relevant.It is concluded that the plastic deformation of NiTi wires is initiated by deformation twinning in oriented martensite, accompanied by dislocation slip in austenite and/or martensite in extent depending on the test temperature and total strain. The deformation twinning is found to play an ambiguous role in NiTi deformation. When it proceeds at low temperatures (T ≤ 20 °C) beyond the yield point, it raises recoverable strain up to 13%, while at high temperatures (T ≥ 50 °C) when it proceeds already within the plateau range as intermediate step of the stress induced B2=>B19’=>B2T martensitic transformation, it restricts the recoverability of transformation strains. The repeated deformation twinning in oriented martensite enables low temperature deformation of NiTi wires with specific microstructure up to ∼50% strain and causes severe microstructure refinement during the mechanical and thermomechanical processing of NiTi.

Computer method of processing of deformed steel wire microstructures images for its properties analysis

Mechanical properties of board-bronzed wire depend from one side on the wire rod microstructure from which it is produced and from the other side – determines by peculiarities by the microstructure of the wire itself. At present, there are no generally accepted methods of deformed wire microstructure analysis allowing establishing relationship between characteristics of wire deformation and microstructure characteristics. A mathematical apparatus and new algorithm for processing of microstructure of pearlite steel wire after drawing elaborated based on microstructure image processing and its parameterization. As the main parameter of microstructure, the density function of statistical distribution of fiber lengths used, which allows characterizing quantitatively image of microstructure. Based on the experimental data of OJSC “BMZ – management company of “Byelorussian metallurgical company” holding” correlation demonstrated between degree of wire twisting and degree of delamination. On the basis of samples of perlite steel and their images obtained for bronzed bead wire manufactured at OJSC “BMZ – management company of “Byelorussian metallurgical company” holding” density functions of statistical distribution of perlite microstructure fiber length for the group of samples calculated. Criteria for wire microstructure analysis, based on density distribution function along length of fibers, as well as reduced distribution function proposed. Correlation between degree of delamination, number of wire twists and characteristics of its microstructure determined, calculated using the distribution function of wire fibrous structure with pronounced texture in the cross section.

Temperature and microstructure dependence of localized tensile deformation of superelastic NiTi wires

Superelastic NiTi wires possessing wide range of microstructures were deformed in tensile tests up to the end of the stress plateau in a wide temperature range −20 – 200 °C, unloaded and stress free heated to ~200 °C. The recoverability of upper plateau strains was evaluated in dependence on the test temperature and wire microstructure. At low temperatures below 20 °C, the upper plateau strains are fully recoverable upon unloading and heating. With increasing test temperature, however, the recoverability of upper plateau strains becomes gradually lost. Unusually long upper plateaus (10–17%) were observed at test temperatures, at which the upper plateau stress approached the yield stress for plastic deformation of martensite. The volume fraction of the martensite phase at the end of the stress plateau (evaluated by in-situ electric resistance and synchrotron x-ray diffraction) decreases with increasing test temperature in the range where the long plateaus were observed. TEM analysis revealed high density of {114} austenite twins in wires deformed in this temperature range. These observations are rationalized by gradual increase of the activity of the stress-induced B2 → B19′ → B2T martensitic transformation into twinned austenite and plastic deformation by dislocation slip with increasing test temperature.

The Alternative Coating Method For Zinc Phosphate Coating before Cold Deformation of High Carbon Steel Wires

The Alternative Coating Method For Zinc Phosphate Coating before Cold Deformation of High Carbon Steel Wires

Beyond the strain recoverability of martensitic transformation in NiTi

Tensile deformation of a medical grade NiTi wire was investigated in a wide temperature range from −100 °C to 450 °C. Supplemental in-situ electrical resistance, synchrotron x-ray diffraction, digital image correlation and ex-situ TEM methods were employed to characterize deformation/transformation processes acting at high temperatures and stresses. Conventional superelastic deformation due to stress induced martensitic transformation taking place around room temperature becomes gradually accompanied by dislocation slip in the temperature range 30–80 °C. With further increasing temperature, stress induced martensitic transformation still proceeds in localized manner but the length of the forward stress plateau increases, volume fraction of the martensite phase at the end of forward stress plateau decreases, unrecovered strain increases and {114} austenite twins appeared in the microstructure of deformed wires. These observations were explained by the activity of a new deformation mechanism - stress induced B2=>B19´=>B2T martensitic transformation into twinned austenite coupled with dislocation slip. Thermodynamic and crystallographic aspects of this B2=>B19´=>B2T martensitic transformation breaking the strain recoverability limit of cubic to monoclinic martensitic transformation were outlined. To rationalize the observed thermomechanical responses of the wire at elevated temperatures, a TRIP like deformation mechanism based on this transformation was incorporated into an existing constitutive model of thermomechanical behaviors of NiTi. The model was numerically implemented into finite element code, simulations were performed and compared with the experimentally observed behaviors. It was found that the B2=>B19´=>B2T martensitic transformation destroys the shape memory functionality of NiTi but renders it excellent ductility in thermomechanical loads, introduces nanoscale heterogeneity into its austenitic microstructure and allows for its low temperature processing and shape setting.