Slide Plate Research Articles

Numerical simulation of impact response for pantograph slide plate

As a key component, the performance of pantograph slide plate is directly related to the normal operation of train and the stability of power supply. The pantograph slide plate is exposed to the complex environment and thus it would face mechanical impacts. In this paper, two types of slide plate models (wide and narrow) are constructed to explore the mechanical behavior of pantograph slide plate under impact using the finite element method. The results show that the slide plates rapidly deform at the beginning of the impact, and then the stress variation speed gradually slows down and tends towards a stable and low amplitude of self vibration. Under strong impact, the vibration frequency and amplitude of the slide plate significantly increase. The stress level of wide slide plate is lower than that of narrow slide plate. Narrow slide plate exhibits higher sensitivity and instability. This indicates that when the train is running at a high speed, factors such as track irregularities and airflow disturbances have a more significant impact on the narrow slide plate. This work provides valuable references for subsequent optimization design.

PSPMoni: A Robust Wear Monitoring Method of Pantograph Slide Plate

The pantograph slide plate (PSP) plays a crucial role in the daily maintenance of trains by transmitting electrical energy from the contact wire (CW) to the train. Automatic monitoring of PSP wear condition is essential to notice abnormal wear promptly. In field applications, the target PSP edge may be obscured by the rear side PSP due to the operating attitude of the pantograph, leading to false detections and interfering with the field maintenance work. Meanwhile, the scenario of the PSP occlusion is characterized by randomness, which brings a considerable challenge to the reconstruction of the occluded edges. A robust PSP wear monitoring method is proposed to improve the performance of wear detection in field applications, considering the PSP occlusion scenarios. Firstly, the wear area of the PSP is localized using the YOLOv5s model. Subsequently, a fusion of the morphology method and the Canny operator is employed to extract the edge of the PSP. Different occlusion types are identified through detailed observation, and corresponding edge reconstruction methods are proposed for occluded edges. Finally, a robust wear condition evaluation method and five evaluation criteria for assessing wear condition are introduced. Experimental results demonstrate that the system achieves accurate PSP wear detection with an accuracy of 0.6 mm, and the reconstructed edge at occlusion locations closely matches the target edge compared to other automatic systems.

Improved sinterability and thermal shock resistance of MgO–ZrO2 composites due to in-situ formed MgAl2O4

To solve the problems of high cost and high firing temperature of ZrO2 inserted rings of slide plates, the in-situ MgAl2O4 (MA) toughened MgO–ZrO2 new ring materials were prepared using lightly calcined MgO, m-ZrO2 and nanoscale Al2O3. The effects of MgO/ZrO2 ratio and the amount of nanoscale Al2O3 on properties of samples were investigated. The results showed that the sinterability and mechanical properties of MgO–ZrO2 composites improved significantly due to the MA formed in situ by reaction between MgO and Al2O3, which promoted reactive sintering and densification of the samples. The improved thermal shock resistance (TSR) in MA-toughened MgO–ZrO2 composites was attributed to microcracks developed due to thermal expansion mismatch, MA and ZrO2 also acted as bridging particles, improving the ability to prevent crack propagation of the composites. The optimum MgO/ZrO2 ratio and addition amount of nanoscale Al2O3 were 7/3 and 3 wt%, respectively.

High frequent cyclic ablations of AlSi alloy modified C/C-SiC-ZrB2-ZrC at different temperatures

Modified C/C composites are promising candidates to the advanced piston of internal engine, pantograph slide plate and rapid-fire gun barrel. To understand the corrosion in the working conditions of these thermal components, cyclic ablations of C/C-SiC-ZrB2-ZrC (C/C-SZZ) were carried out in high frequent impacted combustions at different temperatures (700–2300 ℃). Parallel study of AlSi alloy modified C/C-SiC-ZrB2-ZrC (C/C-SZZ-AS) which had lower cost was performed synchronously for comparison. Results indicated that the ablation rates of both the composites went down with decreased temperature while C/C-SZZ-AS presented a faster decline. Compared with C/C-SZZ, the pressure infiltrated AlSi alloy matrix of C/C-SZZ-AS raised the conductivity and specific heat capacity but reduced the emissivity, which led to a lower surface temperature and thermal gradient during ablation. And combined with the better plasticity and toughness of the alloy matrix, C/C-SZZ had stronger ablation resistance below 1500 ℃ in the serious thermal shock. At temperature above 1500 ℃, excessive phase transformation of the AlSi alloy matrix caused more defects and strengthened the mechanical erosion. And then the faster consumption of the AlSi alloy resulted in the greatly worsened ablation property of C/C-SZZ at 2300 ℃.

Corrosion mechanism and microstructure evolution of industrial used Al2O3-ZrO2-C slide plates

Slide plates are one of the most important functional refractories that control the flow of molten steel from the steel ladle to the tundish. In order to improve the service performance of slide plates and accelerate continuous production of the steel industry, a detailed post-mortem analysis was necessary. In this study, the corrosion behaviors of the high-temperature heated Al2O3-ZrO2-C slide plate used one heat for a 200 tons steel ladle in industry were investigated. The results showed that the thermo-mechanical properties' mismatch led the formation of radial cracks, which was the main factor limiting the service life of the slide plates. Besides, corrosion microstructure revealed the dissociation of mullite-zirconia aggregates and the loss of graphite provided a channel for the penetration of molten steel. The penetration of molten steel could react with Al2O3 in the slide plates, which accelerated corrosion in the early stage and formed a composite spinel layer in the later stage to block corrosion. Also, acicular CaAl12O19 was formed behind the composite spinel layer, further blocking the penetration of molten steel. Furthermore, the ZrO2 from mullite-zirconia had an interlocking structure to prevent corrosion. Finally, the content and viscosity of the liquid phase at different positions of the used slide plates were calculated, which indicated that the area near the casting hole had more liquid phase and lower viscosity. This would further optimize the service performance of the slide plates.

DEVELOPMENT AND CHARACTERISATION OF PANTOGRAPH SLIDES FOR RAILWAY APPLICATIONS: A SHORT REVIEW

High-speed railways have transformed global transportation, leading to increased economic activity and reduced congestion. Railway development is surging in Asia, encompassing upgrades to existing lines and the construction of new high-speed railways. This article explores the materials, processes, and properties of pantograph slides. A pantograph slide is an important component of top-running rails that enables the transmission of electrical energy from traction substations to moving trains. This review presents the evolution of pantograph slide materials, such as metal slide plates, pure carbon slides, powder metallurgy slides, metal-impregnated slides, and composite slides. The characterisations of pantograph slide properties, such as density, resistivity, hardness, impact, and flexural properties are also reported. This article delves into the utilisation of local materials, particularly carbon derived from palm kernel shells and coconut shells, as well as graphene from petroleum coke, for the development of current collectors. These findings may contribute to the understanding of pantograph slide materials and provide insights into the potential use of sustainable materials in high-speed railway systems.

Strengthening mechanism of Al2O3–ZrO2–C sliding plate material by existence modes of in-situ generated β-SiC whiskers

Al2O3–ZrO2–C slide plates are commonly used in sliding nozzle system because of their excellent mechanical properties and slag corrosion resistance. In this work, high-performance Al2O3–ZrO2–C slide plate material were prepared by adding antioxidant silicon to raw materials. SiC whiskers were formed in-situ at a temperature of 1500 °C in a carbon-buried atmosphere. The strengthening mechanism of SiC whiskers in various aspects was systematically studied. The results showed that SiC whiskers have three existence modes, four strengthening and toughening effects and four mechanisms of inhibiting slag corrosion in the Al2O3–ZrO2–C slide plate material. This enhanced the material's mechanical properties and the slag corrosion resistance. In general, compared with the material without antioxidant silicon, the cold crushing strength of the material with 4 wt% silicon increased by 127.2%, and the specific fracture energy increased by 94.0%, and the slag corrosion resistance of the material with 3 wt% silicon increased by 46.3%.

Study on Friction and Wear Properties of Copper-Impregnated Carbon Slide Plate Under Different Humidity Conditions

The pantograph–catenary system is one of the most commonly used power-receiving modes of metro trains. Its friction and wear performances are related to the safety and stability of train operation. In this study, a copper-impregnated carbon slide plate material, widely used in numerous metro lines in China, is considered as the research object. The problem of abnormal wear of slide plates caused by the decrease in relative humidity in the autumn and winter in tunnels is studied. Current-carrying friction and wear tests under humidity conditions of 20%, 30%, and 40% relative humidity (RH) are performed to reveal the mechanism of seasonal abnormal wear of slide plates and provide a reference for the service of pantograph slide plates under low-humidity conditions. The results reveal that relative humidity significantly influences the wear process of slide plates; further, the wear rate decrease with an increase in relative humidity. As observed by laser scanning confocal microscopy, with an increase in the relative humidity, the mechanical wear of the slide surface is weakened, arc erosion is enhanced, and surface roughness is increased. The Raman spectral scan showed that with the increasing humidity, the graphitization of the surface material decreased significantly, and the molecular structure changed greatly. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analysis reveal that under high humidity conditions, a relatively complete oxide film forms on the slide plate and plays a role in lubrication and protection.

Research on drag reduction performance of sliding plate of rice direct seeding machine based on non-smooth structure of loach surface

Sliding plate has the problems of large sliding resistance and serious soil adhesion. Loach moves freely and flexibly in mud, has highly efficient lubrication and drag reduction effects. The sliding plate of rice direct seeding machine was selected as the research object and loach as the bionic prototype. The macroscopic and microscopic structure characteristics of loach were observed, the body surface of loach was covered by scales, which had a ridged non-smooth structure. The simulation analysis of the drag reduction performance of the non-smooth structure was carried out, the maximum drag reduction rate was 2.55% at the speed of 1 m/s. A bionic sliding plate of rice direct-seeding machine was constructed based on the non-smooth structure of loach body surface, and its working performance was simulated and analyzed. The results of orthogonal test show that the order of primary and secondary factors of bionic structure parameters affecting drag reduction rate was ribbed spacing > ribbed width > ribbed height. The optimal parameter combination was ribbing height 4 mm, ribbing width 4.5 mm, ribbing spacing, and the optimal drag reduction rate was 4.21%. The results of this study can provide theoretical support for bionic design of soil-engaging components in wet and soft paddy field.

On the tribological behaviors of Cu matrix composites with different Cu-coated graphite content

Graphite/Cu composite is widely used in pantograph slide plates. To further understand its lubrication behaviors, the tribological properties of graphite/Cu composites with different graphite content were studied using ball-on-disk wear tests. The results reveal that the composites contain only graphite and Cu phases. The tribological results show that the friction coefficient and wear rate of 7 wt.% graphite/Cu composite were decreased 7.7% and 12.7%, respectively, compared with 5 wt.% graphite/Cu. However, both friction coefficient and wear rate increased with the graphite content exceeding 7 wt.%. The excellent tribological properties of the composites were mainly attributed to the synergistic action of the oxidative trib o-layer and graphite lubricant film, which is composed of graphite, Cu, CuO, and Fe2O3. The wear mechanism of the graphite/Cu composites was mainly abrasive wear, accompanied by adhesion and oxidation wear.

Role of nano-Al2O3 particles in improving the properties of MgO–C slide plate materials

The unfired Al–Si incorporated MgO–C slide plate materials were manufactured using magnesia aggregates and fines, SiC aggregates, Al, Si and B4C powders as the raw materials, trace nano-Al2O3 particles as additive, and phenolic resin as binder. The contributions of nano-Al2O3 in the properties, phase composition and microstructure of MgO–C materials were studied. The reseult indicates that nano-Al2O3 is beneficial to improve mechanical properties of the materials, which is attributed to the good filling and pinning effects of nanoparticles. Highly reactive nano-Al2O3 can promote the densification of MgO–C materials and in-situ formation of ceramic phases at high temperatures, and a large number of non-oxide whiskers contributes to the formation of a continuous interlocking networks, which improves the high-temperature strength and TSR of MgO–C materials. Moreover, nano-Al2O3 promotes the formation of fine-grained pinel and forsterite protective layer in the high-temperature oxidizing atmosphere and prevents the diffusion of oxygen into the interior of the material, thus improving the oxidation resistance of MgO–C refractories.

Extra Periosteal Sliding Plate, a New Surgical Technique for the Treatment of Fractures of the First Metacarpal and Proximal Phalanx

Background: One of the most important objectives when performing an open reduction of a fracture is to achieve a stable internal fixation with minimal damage of the periosteum to preserve irrigation in the fracture site and thus promote adequate healing. Minimally Invasive plate osteosynthesis (MIPO) follow this key technical point with great effectiveness and efficiency, however, a reduction technique with these characteristics for the management of hand fractures has not yet been widely described for the management of hand fractures. Methods: The authors technique proposes a new surgical technique “extra-periosteal sliding plate” fixation for first metacarpal and proximal phalanx fractures. Data are obtained from 9 patients from June 2022 to January 2023 and a threemonth postoperative follow-up is performed where functionality and rehabilitation results are evaluated. Results: In total nine patients underwent to the described technique achieving adequate fracture stability and total bone healing with favorable functional outcomes without sequelae. Conclusion: Extra-periosteal sliding plate fixation is considered a great surgical option for the management of hand fractures, specially in those patients with severe trauma in whom vascular and soft tissue integrity must be preserved, providing suitable functional outcomes.

Research and Experimental Application of New Slurry Proportioning for Slag Improvement of EPB Shield Crossing Sand and Gravel Layer

Based on the construction practice of the Beijing Metro Line 10 shield tunneling project, this paper describes research on soil improvement technology for Beijing stratum characteristics (sandy gravel stratum) and covers similar engineering conditions. It also describes the development of a new type of mud improver. Based on the laboratory tests with bentonite as the base mud and different additives, the effects of guar gum, CMC, xanthan gum, and clay medium particles on mud performance are analyzed. Then, two kinds of mud were used to conduct indoor simulated muck improvement tests (mixing test, slump test, sliding plate test, and adhesion resistance test), and the improvement effects of new mud and ordinary mud applied in pebble/round gravel and sandy soil layers were compared. The results show that xanthan gum is the best material to improve the performance of slurry, using the contrast test of bentonite-based slurry and different additives. The optimum slurry preparation scheme is 4% bentonite, 0.2% xanthan gum, 0.04% soda ash, and 1% clay particles. Using indoor simulated muck improvement tests (mixing test, slump test, slide plate test, and adhesion resistance test), the improvement effects of applying new mud and ordinary mud in pebble/round gravel and sandy soil layers are compared, and the advantages of the new mud in the application of the above two formations are verified. Among them, the new slurry has great advantages for improving the two parameters of the soil adhesion resistance coefficient and slump during shield tunneling. When the improved soil mass reaches the flowing plastic state, the proportion of new mud added to different soil mass is different. The proportion of new mud added to improved pebble/pebble soil is 28%, and that of sand and clay is 32%. It can be seen that new mud is more suitable for improving pebble/pebble soil.

Mechanical Action Mechanism and Crack Response Analysis of Slide Plate of No.12 Turnout

In the course of maintenance and repair, the railway workshops of the Lan-Qing railway found that the slide plate was prone to injury and damage. In order to study the actual stress state of the slide plate during the running of the train, a finite element model of the slide plate and related components was established based on ANSYS, Hypermesh was used for meshing and mesh quality control, and the Mooney-Rivlin constitutive intrinsic model was selected to simulate the rubber plate. The stress state of the slide plate when passing through the turnout in the straight and lateral directions is analyzed respectively. The results show that there is stress concentration at the root of the tongue depressor of the slide plate, and large deformation exists in the middle of the base plate, the front end of the platform plate and the position of the guide iron when passing through the turnout directly and laterally. The stress state of the slide plate is simulated when the rail brace fails, and the maximum stress is found to be 279.24 MPa, which exceeds the material yield limit. Therefore, we should pay attention to the inspection of the condition of the rail brace during the maintenance and repair. Presenting cracks at the weld seam location, it is found that the crack has a significant effect on the dewelding of the slide plate, and the heel position is the weakness of the slide plate. When the crack length reaches 1.2 mm, there is a tendency to crack at the weld seam position of the slide plate, and when the crack length continues to increase, the crack will further expand and jeopardizing structural safety. The research results can provide a theoretical basis for the improvement, disease prevention and maintenance of the slide plate.

Interfacial Modification of Ti3AlC2/Cu Composites by Multi-Arc Ion Plating Titanium

Cu matrix composites reinforced with Ti3AlC2 ceramics can be applied for electrical contact materials, such as vacuum contact material or a pantograph slide plate. However, Ti3AlC2 particles substantially decomposed because lattice diffusion is the main way that Al atoms diffused into the Cu matrix and were uniformly distributed. In order to suppress the decomposition of Ti3AlC2 ceramics and improve the properties of Ti3AlC2/Cu composites, the surface of Ti3AlC2 was modified by multi-arc ion plating Ti. The results shows that, with the volume fraction increasing of Ti3AlC2, the decomposition of Ti3AlC2 is exacerbated and the lattice constant of Cu(Al) solid solution is bigger. In the meanwhile, the structure of Ti3AlC2 changes from dispersed granules to flakes, then to a continuous network. Multi-arc ion plating Ti effectively inhibits the diffusion of Al atoms into Cu matrix. The Ti coating reacts with Cu and generates CuxTi in the interface between the Cu and Ti coating, which inhibits the diffusion of Al atoms so as to inhibit decomposition., the inhibition of decomposition of Ti3AlC2 ceramics weakened solid solution strengthening and decreased the content of hard phase TiCx. Furthermore, the good mutual diffusion between CuxTi layer and Cu effectively improves the interfacial bonding strength.

Effect of in situ formation of Ti(C,N) on the properties of Al2O3–ZrO2–C slide plate material

AbstractAl2O3–ZrO2–C slide plate was ordinarily used in sliding nozzle system because of its excellent mechanical properties and slag corrosion resistance. This study improved the slag corrosion resistance of the slide plate by the carbothermic reduction of TiO2 and aluminothermic reduction of TiO2 under high temperature in coke bed to generate Ti(C,N) phase in situ. The result revealed that TiC of the high melting point phase could enter into anorthite (CaAl2Si2O8) of the low melting point phase, forming eutectic phase CaAl2Si2O8–TiC, and improve the viscosity of the slag. Furthermore, TiC and CaAl2Si2O8 captured FeO and MnO from the slag, resulting in the increase of the slag viscosity, inhibiting the penetration corrosion of the slag, and improving the slag corrosion resistance of the materials. In general, compared with the material without TiO2 powder, the slag corrosion resistance of the material introduced 2 wt.% TiO2 powder was increased by 24%. Meanwhile, the cold crushing strength of fired specimen at room temperature was increased by 35.6%.

Evolution of iron-based raw materials and their effect on the properties of MgO-Al-C slide plate materials

Evolution of iron-based raw materials and their effect on the properties of MgO-Al-C slide plate materials

Role of nano-ZrO2 powder in in-situ formation of ceramic whiskers in Al2O3-C slide plate materials

The effects of nano-ZrO2 powder on the evolution of phase composition and microstructure of Al2O3–C materials during firing have been investigated using tabular alumina, Si powder, Al powder, graphite and nano-ZrO2 powder as starting materials. The residual content of Al and Si gradually decreased with increasing temperature, and the added nano-ZrO2 facilitates the reactions involving Si and Al. The quantity of in-situ synthesized AlN and SiC whiskers exhibiting continuous interlocking networks increased gradually with temperature. Nano-ZrO2 facilitates more ceramic whiskers generated in samples, which play a strengthening and toughening role in the materials, thus improving the thermal shock resistance and high temperature strength of Al2O3–C materials. In addition, physical properties are improved due to the nano-ZrO2 filling the pores and increasing the density of materials.

Preparation and application of MgO/nano MgAl2O4 core-shell aggregates with improved hydration and thermal shock resistance

MgO/nano MgAl2O4 core-shell aggregates were prepared using nano-Al2O3 suspension and MgO aggregates by vacuum impregnation method and then heat treated. The MgO/nano MgAl2O4 core-shell aggregates possess excellent hydration resistance and thermal shock resistance (TSR), which are attributed to the in-situ formed MgAl2O4 reducing the contacting area between MgO and water as well as the reduced pore and pore size. The pinning effect of nano-MgAl2O4 and thermal mismatch between MgO and MgAl2O4 contribute to improving TSR of aggregates. The TSR and hot modulus of ruputure were enhanced when the prepared MgO/nano MgAl2O4 core-shell aggregates were introduced into MgO–C slide plate.

3D Modelling of Scrap Minimizing Machine

Abstract: Ill as taking care of and transportation of metal chips. Endeavours have been taken to guarantee an effective squander the board framework in shop floors, with least utilization of space and energy with regards to discarding Meta. There are a few modern creation processes that include mechanical machining of cast parts by different activities like turning, processing, and boring. Metal Chips, particularly of aluminium, gentle steel and cold-moved carbon steel, and so on. The assortment, stockpiling, and transportation of metal chips are a significant angle during the time spent reusing. This project centres on the compaction and making of metal chips parcels for simplicity of capacity as well chips framed during machining processes. The huge space required to store the chips as free chips have a huge surface region. The extent of the task is restricted to the plan, investigation, and manufacture of scrap baling machine. A Baling press machine is a machine where a free piece is changed over into in the structure of 8-12 kg group. In this machine, we take on a square group as opposed to roundabout shape and square parcels get less space when contrasted with the round bunches. Keywords: DC Motor, Switch Mode Power Supply (SMPS), Power Switch, Guide Way, Sliding plate, lead screw.