Wiring Layers Research Articles

Investigation of formation, microstructure and hardness of Ti-6Al-4V single tracks via Joule-fused filament additive manufacturing

Purpose This paper aims to investigate a novel additive manufacturing (AM) method for titanium alloy using Joule heat as the single heat source to melt TC4 wire, which intends to provide a new low-power, low-cost solution for the processing of titanium alloys. Design/methodology/approach When current flows through the wire and the substrate, Joule heat will be generated to melt the wire and join the wire with the substrate. By stacking the wire layer by layer, finally a part can be formed. The cross-sectional morphology, microstructure and hardness of TC4 single track deposits formed by Joule heat melting wire AM were investigated by various characterization methods. Findings The melting width and melting penetration decreased with the increase of printing speeds. There is no obvious change in single track morphology with the change of printing pressures. The melting width and melting penetration increased with the increase of printing currents. The observation of the internal microstructure of a single track reveals a decrease in grain size as printing speeds increase. The average hardness of the single track was about 363 HV, which is comparable to the hardness of the parts fabricated by selective laser melting process. The printing power is less than 300 W, which is lower than other AM processes. Originality/value This paper provides a novel solution for the processing of titanium alloy parts. Compared with other expensive energy sources, this work only uses an ordinary DC power supply as the energy source. The printing process is simple and the cost is low. The power is much lower than other AM processes.

Study on the influence of pipe effect on the vibration characteristics of electro-hydraulic exciter

In this paper, an electro-hydraulic exciter controlled by an alternating current distribution valve is proposed, and a systematic analysis of the influence of pipe effect on the vibration characteristics of the electro-hydraulic exciter is investigated by simulation and experiments. The vibration characteristics curves for different pipe parameters are obtained, and the relative errors between simulation and experiment are evaluated. Moreover, a significant regression model of pipe parameters and vibration characteristics of the electro-hydraulic exciter is established by using the quadratic regression analysis method and the Box-Behnken experiment design method. Significant differences in the influence of pipe parameters on vibration characteristics are obtained by ANOVA (Analysis of Variance), and the influence of pipe parameter interaction on vibration characteristics is discussed. The results show that the relative importance of pipe parameters on the vibration characteristics of electro-hydraulic exciter, from high to low, is as follows: pipe diameter, elastic modulus, and pipe length. Notably, there is also an interaction between the pipe parameters, and the significance of these interactions is ranked from high to low as the interaction between the layers of steel wire and diameter, the interaction between diameter and length, and the interaction between the layers of steel wire and length.

Evolution mechanism of interfacial multi-layer intermetallic compounds and failure behavior in the Al–Au wire bonding

Evolution mechanism of interfacial multi-layer intermetallic compounds (IMCs) and their impact on failure behavior in Al–Au wire bonding after thermal storage and thermal cycle process are investigated. Microstructural analysis shows that multi-layer IMCs form between the Al wire and barrier layer. After thermal storage and thermal cycle process, the Au8Al3 layer transforms into AuAl2, and Au pad transforms to a thicker layer containing Au2Al and AuAl. Thermodynamic analysis indicates that Au8Al3, Au2Al, AuAl, and AuAl2 have increasing stability. Small-size, equiaxed AuAl2 grains form due to high stored energy, while large-size, columnar Au2Al and AuAl grains result from slower reaction rate and limited recrystallization. The stack-like formation of AuAl2 grains is attributed to the balance between driving force and interfacial energy resistance. During thermal storage, thicker IMC layers cause cracking between IMC layers and Au pad, and micro voids form near the IMC layers/barrier layer interface due to Kirkendall effect. Thermal stress results show that plastic deformation of the Al layer slightly affects the thermal stress in other layers during the thermal cycle process. The cyclic stress at the interface with initial cracks ranges from −157 MPa to 114 MPa, facilitating crack propagation. Additionally, micro void grows under cyclic thermal input, weakening interface adhesion. Therefore, bond strength decreases and frequency of bonding lift-off with cracking along the IMC layers/barrier layer interface increases after thermal storage and thermal cycle process. These results provide the guidance for regulating the interfacial IMCs and predicting the thermal stress in Al–Au wire bonding.

Chemical mechanical polishing for copper films in integrated circuit wiring layers using an advanced slurry

In the chemical mechanical polishing process of integrated circuits (IC) copper (Cu) wiring layer, it is difficult to balance between material removal rate (RR) and surface quality. To solve this problem, a novel slurry composed of dodecylbenzene sulfonic acid (DBSA), 2-aminobenzimidazole (2-ABI) and multi-walled carbon nanotubes (MWCNTs) was proposed. The Cu surface roughness of 0.63 nm with RR of 5290 Å/min had been achieved. Polishing, electrochemical experiments and molecular dynamics simulations revealed that when DBSA: 2-ABI= 1: 4, the strongest inhibition effect was obtained. Quantum chemical calculations showed that the strong interaction force of hydrogen bonding between 2-ABI and DBSA greatly enhanced the inhibition efficiency. Surface morphology testing showed that the addition of MWCNTs could effectively reduce scratches.

Studies on the Evolution of Fatigue Strength of Aluminium Wires for Overhead Line Conductors.

Traditional ACSR overhead wires, which consist of a high-strength steel core and several layers of aluminium wires, are currently the most popular overhead line conductor (OHL) design globally. Operating conditions, particularly operating under varying stresses from Karman vortices, lead to the fatigue cracking of wires of the outer layer, followed by wires of the inner layers. Karman vortices are formed by the detachment of a laminar wind stream flowing around the conductor, which causes vibrations in the conductor called wind or aeolian oscillations. Aluminium wires are manufactured using standard batch material drawing technology. Although the fatigue strength of such wires is not standardised, there are various criteria for evaluating this characteristic, as well as established limits on the number of cycles needed to break the first wires of the outer layer. Fatigue strength also strongly depends on the geometric structure of the wire and its operating conditions. The article analyses the influence of the mechanical condition of aluminium wires used in ACSR cables on their fatigue strength. We then present results from aluminium wire fatigue tests conducted on a specially constructed test rig. In addition, fatigue cracks were interpreted using scanning microscopy.

Temporal and Spatial Variation Study on Corrosion of High-Strength Steel Wires in the Suspender of CFST Arch Bridge

The corrosion and degradation behavior of high-strength steel wires during service directly affect the safety and usability of suspenders in steel pipe concrete arch bridges. In this study, three different types of specimens were fabricated using steel wires extracted from the suspenders of an 11-year-old in-service arch bridge and subjected to accelerated corrosion tests with acetic acid. Considering the differential diffusion processes of corrosion factors caused by varying degrees of damage to the suspender sheath, the spatial corrosion variability of steel wires at different positions within the suspender cross-section was investigated. Experimental results indicated a two-stage characteristic in the corrosion process of individual galvanized steel wire samples. In the first corrosion stage, the microstructure on the corroded steel wire surface evolved from a dense crystalline structure to a porous one. In the second corrosion stage, corrosion products accumulate on the steel wire substrate, subsequently further aggregating into sheet-like structures. The maximum pitting factor of individual steel wire samples from a specific area could be described by a Type I extreme value distribution. In the time-dependent model that was established, the location parameter and scale parameter exhibited an exponential decrease during the first corrosion stage and a linear decrease during the second corrosion stage. In the absence of sheath protection, the coefficient of variation in corrosion among adjacent steel wires in the suspender followed a normal distribution. The spatial corrosion variability of the wires inside the suspender is significantly influenced by the shape of the suspender sheath damage. As the corrosion time increased, the overall discrepancy in corrosion levels among different layers of wires diminished.

Microstructure and mechanical properties of 7075/5356 aluminum alloy laminated composite fabricated by wire arc additive manufacturing

A 7075/5356 aluminum alloy laminated composite was fabricated by alternately depositing a 7075 wire and a 5356 wire layer by layer using wire arc additive manufacturing (WAAM). The microstructure and mechanical properties of the produced components under as-deposited and heat-treated conditions were investigated. The results revealed that the grain morphology of the specimen was mainly composed of equiaxed grains in each layer, while the grain size of the interlayer region was reduced due to the heterogeneous nucleation relying on the partially remelted previous layer. Moreover, a reduced amount of second phase was observed due to decreased Zn and Cu alloying elements content in this region, which resulted in a gradient change in microhardness distribution. The tensile strength and elongation of the heat-treated samples in vertical and horizontal directions were 321 MPa, 10.12 %, and 377 MPa, 9.72 %, respectively. The results indicated good comprehensive mechanical properties, which is promising for further application of WAAM fabricated laminated metal composite.

A one step method to prepare polymer‐based flexible wires by continuous spatial‐confining network assembly technique

AbstractIn recent years, flexible electronics technology has been developing rapidly, and flexible electronic devices have been widely used in wearable gadgets and robotics. Flexible wires are the basic components of these devices, which usually consist of metallic materials with flexibility and ductility. However, the introduction of flexible conductive materials has broadened the application scope of flexible wires. In this paper, PDMS/SCF conductive composites exhibiting different conductivity properties on both sides are fabricated by adding meshes based on the continuous spatial‐confining network assembly method. The conductivity of PDMS/SCF (6 wt%) composites can be exhibited as 173.45 S/m in the conductive layer and 6.25 × 10−11 S/m in the insulating layer, which can be used as core and surface layers of conductors, respectively. A mathematical model is also developed to predict the electrical conductivity of the PDMS/SCF conductive composites, and the experimental data are in good agreement with the predicted results. This work provides a method for the continuous preparation of multifunctional composites that can be molded in one step with conductive layer and insulating layer, which can be used as the core and insulating layers of wires, thus simplifying the preparation process of composite‐based wires and expanding the range of conductive composites applications.

A Theoretical Method for Calculating the Internal Contact Pressure of Parallel Wire Cable during Fretting Wear

Fretting wear of the stay cable is an important factor affecting the service life of the cable. To accurately calculate the extent of fretting wear, it is necessary to calculate the internal contact pressure in the cable. Although there are many theories and experiments on the contact behavior between wires, there are still no theoretical formulations for calculating the distribution of contact pressure in stay cables. In this paper, by studying the transfer effect of contact pressure in the cable, the PIC (parallel wire cable internal point contact pressure) model for calculating the contact pressure in the parallel wire cable is proposed, considering the effects of wire twisting, sheath compression, and cable bending on the contact pressure. A finite element model corresponding to the contact mode between steel wires is established, and the effectiveness of the PIC model is verified through numerical simulation analysis and a comparison of the existing contact models. The results indicate that contact pressure caused by wire twisting (CWT) is superimposed layer by layer inwards, with the contact pressure increasing closer to the inner layers, and its magnitude is mainly related to the axial tension and twist angle. Simultaneously, on the same layer, contact points along the diagonal experience the greatest contact pressure. Contact pressure caused by sheath compression (CSC) is assumed to conform to the Boussinesq distribution, with the outer layers exhibiting greater contact pressure compared to the inner layers. Contact pressure caused by cable bending (CCB) conforms to the two-dimensional closely arranged contact force transmission model, has a clear layering phenomenon, and the contact pressure within the same layer does not change significantly. The magnitude of the contact pressure is exponentially related to the curvature of the cable and proportional to the tension of the cable, which explains the reason why the slip occurs later for the cables with high tensile forces. Among these three types of contact pressure, CWT is the greatest, followed by CCB, while CSC is the smallest. The theoretical analysis results show that factors such as wire radius, tension, torsion angle, and wire position have an impact on contact pressure. Contact pressure is transmitted along force chains within the cable, following the superposition law between layers. It is uncertain whether slip occurs in the neutral axis or in the outermost layer because of the different distributions of tangential force and interlayer frictional resistance between the layers of wires. Fretting wear simulations of two wires demonstrate that contact pressure has a significant influence on wear patterns, and the “averaging” of contact pressure is a major reason for achieving uniform interface wear. While the contact width increases proportionally with the contact pressure, excessive contact pressure can complicate the problem by changing the contact mode from gross slip to partial slip. This study provides a theoretical method for calculating contact pressures at any contact point within the cables in engineering practice.

Hydrophilic Bonding of SiO2/SiO2 and Cu/Cu using Sequential Plasma Activation

To meet the increasing market demand for next-generation electronic devices, 3D system integration is getting greater and greater attention. However, traditional methods such as soldering or bump bonding cannot handle high density interconnection. Therefore, hybrid bonding technology, which simultaneously bonds Cu wiring layer and SiO2 dielectric layer, is indispensable. In the hybrid bonding process, hydrophilic bonding is commonly used to bond SiO2 to SiO2. This technique involves bonding of hydrophilic bonding surfaces, followed by post-bonding annealing to achieve a reliable bonding interface. For Cu bonding, it is necessary to break the oxide layer at the Cu bonding interface and allow Cu atoms to diffuse into each other to achieve electrical connection.However, since post-bonding annealing at high temperatures can damage the device or induce residual stress at the bonding interface, low temperature process below 200°C is preferable. Currently, the most widely adopted process is hydrophilic bonding using N2 plasma, which also achieves hybrid bonding through heating at around 350°C to 400°C.In this study, we propose to apply sequential plasma activation bonding (SPAB), which has been shown to be effective for low-temperature bonding of quartz glass, to the bonding of TEOS SiO2 and Cu. SPAB is a technique that forms a highly reactive oxynitrides on the substrate by continuously irradiating the bonding surface with O2 plasma, N2 plasma, and nitrogen radicals. This then adsorbs a large amount of OH groups by reacting with moisture, leading to a strong bond after bonding and post-bonding annealing at 200°C. Since this technique is effective for quartz, it is expected to be effective for TEOS SiO2 as well, and we also investigate its effect on Cu in this study.For this, we investigated the effect of SPAB for blanket TEOS SiO2 and Cu wafer separately. Cu layers were deposited on 4 inch, 525 µm thick Si wafers, and TEOS SiO2 layers on 6 inch, 625 µm thick Si wafers. The Cu layers were deposited by sputtering with a 1 µm thickness, while the SiO2 layers were deposited using plasma-enhanced TEOS process for a 1 µm thickness. Both types of deposited layers were planarized by CMP.The SPAB process was carried out using RIE plasma and microwave radicals of N2 and O2 gas. The bonding surfaces were activated by O2 plasma, N2 plasma, and N radicals sequentially. After the surface activation, the wafers were exposed to ambient air to adsorb water on the surface, followed by bonding in air and post-bonding annealing at 200°C for 2 hours.For comparison, bonding was also carried out using only N2 plasma and only O2 plasma activation, respectively. Results show that when surface activation was performed using only N2 plasma, the bond strength was 0.75 J/m2 for TEOS SiO2 and 0.33 J/m2 for Cu. In the case of O2 plasma activation, the bond strength was 0.57 J/m2 for TEOS SiO2 and 0.98 J/m2 for Cu.On the other hand, the SPAB technique improves the bond strength to 1.13 J/m2 for TEOS SiO2 and 1.03 J/m2 for Cu. Therefore, it can be concluded that the SPAB technique enhances the bond strengths of both TEOS SiO2 and Cu compared to single gas plasma activation. Since the SPAB improves the bond strength of both SiO2 and Cu in the same process condition with annealing temperature of 200°C, this technique will contribute low temperature hybrid bonding applications.

Dynamic capture behavior of rotating matrix to paramagnetic particles in centrifugal HGMS process: Based on FEM

Centrifugal high gradient magnetic separation (CHGMS) was developed to produce a high-quality magnetic product from weakly magnetic materials. In this research, the dynamic behavior of particles in the CHGMS process and the magnetic capture of rotating wires to paramagnetic particles were analyzed through Finite Element Method (FEM). It was found that particles move spirally with slurry in the separation area of the separator, due to the stirring of magnetic wires, and the motion traces of paramagnetic particles are more tortuous and complicated than those of non-magnetic particles. The capture capacity of elliptical wire to paramagnetic particles is stronger than that of circular wire, but is weaker than that of square one. The distance from rotating wires to the center of matrix significantly influences the mass weight of paramagnetic particles captured onto the wires, and there is a clear interaction between wire layers during the capture process of rotating matrix.

Study on axial response of semi-parallel wire suspender with spherical plain bearings

Semi-parallel wire suspenders with spherical plain bearings have untwisting under axial force, and the collision in the untwist process bring adverse effects on the structure. To investigate the axial mechanical response of semi-parallel wire suspenders with spherical plain bearings, the equilibrium equations of suspender are deduced by assuming the distribution of steel wire after deformation, the forms of boundary conditions are distinguished according to the use of spherical plain bearing, and the linear equation expressed by equivalent stiffness coefficients is deduced. The Costello theory and finite element modeling are used to verify the proposed calculation method in this paper, and the influence of suspender parameters on the stiffness equivalent coefficient is analyzed. The results show that the proposed calculation method is suitable for multi-layer semi-parallel wire suspenders; the twist angle and the total number of layers of wires have the greatest effect on the stiffness equivalence factor; when the twisting angle is close to 0, the torsional stiffness of suspender is 0.010–0.21 of that of the steel rod with the same section; the axial tensile stiffness of the conventional suspender is basically the same as that of the steel rod with the same section, but the torsional stiffness is only 0.012–0.023 of the steel rod with the same section, and the tension-torsion coupling effect cannot be ignored. The research results provide a concise method to calculate the axial response of semi-parallel wire suspenders, which lays a foundation for the engineering treatment of the untwisting problem of semi-parallel wire suspender using spherical plain bearings.

A nonlinear finite element framework and Gaussian process-based prediction of stick/slip behaviour in semi-parallel wire cables

This paper addresses the effect of wire slipping on the mechanical properties of structural cables. Based on parameter calibration with experimental data, the paper proposes a Finite Element modelling framework aimed at enhancing the prediction accuracy of the stick/slip behaviour of semi-parallel wire (SPW) cables. The model considers the specific arrangement of the SPW cable composition, interwire friction, and residual interlock between wires. Gaussian Process regression is employed as a surrogate model to reduce the model’s computational cost, optimise parameters and quantify uncertainty. The results show high prediction accuracy when compared with experimental data for different pretension forces. The study finds that wire slip varies considerably between wire layers and is significantly influenced by residual interlock between wires. Additionally, cyclic loading under high bending curvatures reveals that the hysteresis behaviour is dependent on wire slip and loading history. The proposed model accurately predicts the stick/slip behaviour of SPW cables, emphasising the importance of accounting for wire slipping in cable analysis models for various applications.

The study of steel wire winding split type ultrahigh pressure die based on different winding methods

ABSTRACT We propose a novel structure of ultrahigh pressure die which consists of a split compression cylinder, a support ring, and steel wire winding, and the impacts of various steel wire winding methods on the ultimate cylinder pressure-bearing capacity are investigated. The investigations are conducted on the pre-stressing dies using the equal tensile stress (ETS), equal shear stress (ESS), and constant tangential stress (CTS) winding approaches. First, it is determined theoretically what the maximum cavity pressure and the necessary number of winding layers would be. The shear stresses of the cylinder and the support ring, the displacements of the cylinder, and the axial stresses of the steel wire layer are then examined using the finite element method. The results of the theoretical calculation and simulation are compared and discussed. The findings indicate that the ESS winding is a better option.

Inhomogeneity of microstructure and mechanical properties in the interlayer regions for narrow gap laser wire filling welding of 316L stainless steel

A systematic and accurate analysis of microstructural evolution in the interlayer regions of multilayer welded joint is of great importance for in-depth understanding of influence mechanism of uneven microstructure on mechanical properties. Herein, the interlayer microstructure acted on different thermal cycle curves in the upper layer (UL), middle layer (ML) and bottom layer (BL) of narrow gap laser wire filling welding (NGLWFW) of 316L stainless steel with a thickness of 40 mm were compared and investigated through experiment and numerical simulation. Results indicated that the microstructures of components created by NGLWFW exhibit distinct inhomogeneity with multiple rapid thermal cycles caused by repeated weld filling process, which provides a great deal of effect when considering mechanical properties of welded components. The molten pool size and the peak temperature in the UL acquired by simulation are higher than that in other layers ascribed to the high heat accumulation effect. The remelting zone forms between layers owing to the repeatedly heating, cooling and solidification process, which leads to the variation of microstructure from the formed layer to the latter layer. The maximum orientation distribution density and average size of grain in different layers are characterized by distinction presenting a monotonically upward trend from BL to UL. The δ-ferrite phase content in the BL is higher than that in other layers due to higher cooling speed, which results in higher hardness of the BL.

Design of Passive Transmission Line by Adjusting Intrinsic Parameters of Josephson Junctions

Along with the improvement of integration and the requirement of high-speed operation, the passive transmission line (PTL) plays a significant role in superconducting integrated circuits due to its intrinsic advantage of extremely low propagation delay and low signal loss in long-distance transmission. Good impedance matching is critical to reduce the signal reflection in the transmission line and maximize the power transferred. Based on the PTL wiring layer selection under SIMIT-Nb03 process, we studied the equivalent input/output impedance for Josephson junction (JJ) at the IO port and explored a method of impedance matching in rapid-single-flux-quantum (RSFQ) circuits by adjusting the Stewart McCumber parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\beta_c$</tex-math></inline-formula> of the JJ in the design of the PTL's driver and receiver. Furthermore, the accompanying influence from the JJ's modified <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\beta_c$</tex-math></inline-formula> on the performance of the driver and receiver is evaluated to maximize the profit of the functional circuits. The common-used serial resistor is removed to obtain a balanced bias margin for the PTL circuits. The proposed PTL has been designed and tested based on SIMIT-Nb03 fabrication process. ±30% bias margin for the PTL is achieved at low frequency and high frequency (40 GHz) contrast tests, including operation speed and transmission length as test vector. Additionally, a frequency sweep for 1 mm PTL is performed by the designed ring oscillator on the chip. The maximum working frequency is up to 129 GHz, with a margin duration of 8%.

99 Interrupting the composting process for equine carcass skeleton recovery

Proper disposal of equine carcasses continues to be a challenge for equine owners. Recently, composting has been of interest for post-mortem disposal due to pathogen and parasite reduction, and economic concerns associated with traditional burial. Additionally, many educators lack appropriate resources to teach equine skeletal structure due to cost and availability. Study objectives were to 1) determine if in-ground composting can reach over 48.8°C needed for pathogen and parasite destruction and 2) develop methodology to successfully recover full skeletons. Two carcasses (C1 and C2, respectively) were placed in identically constructed pits 1.8–2.4m deep, with 0.6–0.9m of wood pine shavings under the carcass, a layer of metal wire, carcass, followed by 1.2–1.5m of wood shavings on top. A probe thermometer was used to monitor temperature 0.9m down from the pile surface, and weather data including rainfall was collected daily. For C2 only, additional data loggers were placed under the carcass at the rib cage, on top of the animal at the hock, and inside the animal's body cavity. Descriptive statistics were calculated using the means procedure in SAS, where data are expressed as mean ± SD. Carcasses 1 and 2 composted for 187.5 ± 36 d, where excavation time was determined by a plateau in pile temperature, and ambient temperatures ranged from 14.3 ± 9.3°C for C1 and 20.9 ± 6.2°C for C2. Rainfall amounts duringthese periods ranged from 4.2 ± 10.5mm for C1 and 3.3 ± 8.1mm for C2. Midway through the composting process, when temperatures either declined or were failing to increase, the top of the pile was scraped without disrupting the carcass, to increase airflow and provide oxygenation to the carcass below as is customary within composting procedures. Piles were scraped at 92 d for C1 and 85 d for C2. Within the first 107 d of composting, probe temperatures were numerically similar for both carcasses (C1 = 46.6 ± 6.3°C, C2 = 41.4 ± 3.6°C). Data loggers placed on carcass 2 recorded an average of 29.6 ± 0.8°C (min = 20.6°C, max = 31.0°C) under the rib cage, 35.5 ± 2.0°C (min = 20.6°C, max = 37.6°C) on the hock, and 32.4 ± 1.8°C (min = 28.5°C, max = 36.5°C) inside the body cavity. Once carcasses were excavated, bones were immediately washed, and subsequently soaked in an equal part mixture of 3% hydrogen peroxide, 10% ammonium hydroxide, water, and clear dish detergent until grease residues were no longer emitted from bones. Results indicate that ideal temperatures for pathogen and parasite destruction were not always reached within compost piles; however, in-ground composting did prove as an efficient means to obtain teaching skeletons at a low cost ($3,500 per skeleton).

Miniaturized Compact Reconfigurable Half-Mode SIW Phase Shifter with PIN Diodes

In this work, a novel electrically reconfigurable phase shifter based on a half-mode substrate integrated waveguide (HM-SIW) is proposed. SIW is a guided transmission line topology, and by using half-mode excitation, a smaller size can be achieved. Phase shifters are electronic devices that change the phase of transmission for a wide range of applications, including inverse scattering and sensing. The tunability of PIN diodes is applied here to achieve a reconfigurable design. The proposed single-layer structure does not require extra wiring layers for the bias circuit on the suggested printed circuit board. Its principle consists in the integration, in the HM-SIW, of three parallel lines, each connecting the edge of the HM-SIW and linked to a PIN diode and a radial stub. Here we present the results of measurements for a frequency band from 4.5 to 7 GHz that demonstrate how the experiment agrees with simulations. Insertion loss was less than −10 dB, and port coupling was less than −2 dB for both simulation and measurement solutions. The proposed half-mode structure is around half the size of a typical SIW line. With the proposed design, the seven states of the PIN diodes can be validated (ON and OFF), with a wide band adaptation and a relatively constant phase difference across a broad frequency range (44%). A key benefit of the proposed design for a microwave component is the reduction of extra biasing layers for the PIN diodes. This is in addition to the reduced size of the transmission line compared to a commercial SIW. In the annexed section, simulation software is used for a more comprehensive analysis involving more phase shift values and parametric studies.

Study on Process Parameters of Low-power Semiconductor Laser Stripping PTFE Insulating Layer of Aviation Wire

Faced with the increasingly high-quality requirements for the insulation layer stripping at the end of aviation wires, laser wire stripping technology is becoming more and more popular due to its good processing quality and production efficiency. Traditional laser wire strippers generally have problems of bulky size and high control cost and are not suitable for the decentralized processing of large wire harness products. This work explores the feasibility of using a low-power semiconductor laser to strip the PTFE insulating layer of aviation wires. The influence of the parameter changes of each processing factor on the cut morphology of the insulating layer was studied separately. It was found that higher laser power removed more insulating layers per unit of time, but reduced the cutting quality. High laser scanning speed can obtain good insulation cutting quality, but too large or too small scanning speed will reduce the stripping efficiency. Simultaneous improvements in insulation cutting quality and efficiency depend on the right mix of power and scanning speed.

Effect of wire mesh structure parameter on the flame propagation characteristics of syngas explosion

The effect of wire mesh structure parameter on the flame propagation characteristics and intensity of syngas explosion was studied by the visual experiment. The corresponding relationship between the flame propagation and pressure rise of wire mesh two ends under the flame resistance success and failure conditions was analyzed by the comparison. Results indicate that the wire mesh could effectively inhibit the explosion flame propagation and its structure parameter had a great influence on the explosion parameters of wire mesh two ends. As the flame resistance failed, the flame could be greatly accelerated after passing through the wire mesh. And the explosion pressure and flame propagation velocity of wire mesh upper end was obvious higher than those of lower end. As the wire mesh number and layer increased, the explosion intensity was decreased ceaselessly and the inhibition effect was enhanced gradually. For instance, the syngas explosion flame could be completely inhibited under 30 layer and 40 mesh numbers as c = 30 %. ΔPmax were decreased respectively by 81.48 % and 65.52 % at the upper and lower ends of wire mesh. The pressure was greatly reduced as the flame resistance was successful. Especially the reduction in the flame temperature at the upper end of wire mesh. And the temperature did not reach the ignition temperature of syngas. The explosion inhibition was mainly attributed to the combination of the endothermic action and wall effect.