scholarly journals Assessment of Padding Elements Wear of Belt Conveyors Working in Combination of Rubber–Quartz–Metal Condition

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4323
Author(s):  
Dawid Romek ◽  
Dariusz Ulbrich ◽  
Jaroslaw Selech ◽  
Jakub Kowalczyk ◽  
Roksana Wlad
Keyword(s):  
Abrasive Wear ◽  
Surface Treatment ◽  
Quartz Sand ◽  
Welding Process ◽  
Operation Time ◽  
Basic Element ◽  
Metal Elements ◽  
Machine Parts ◽  
Belt Conveyors ◽  
The Impact

Elements of belt conveyors, like other machine parts, are subject to wear processes. The conveyors transporting the spoil in the quartz sand mine are exposed to accelerated wear due to the effect of quartz on metal elements. Intensive wear of metal parts leads to downtime and the need to replace damage parts which generates additional costs. Therefore, it is important to perform surface treatment of metal elements, which will allow to extend the operation time of belt conveyors by reducing wear. The main objective of the article is to determine the impact of the pad welding process of the surface layer of metal elements on the abrasive wear of elements working in the metal–quartz sand–rubber conditions used in belt conveyors. In this research study, three different types of electrodes were used for pad welding the surface. The wear results obtained on the test stand were compared to wear of the basic element without surface treatment. The average wear value of the samples padded with electrode 3 was about 25% lower than the samples without surface treatment. The main mechanism of sample wear was the abrasion process due to the interaction between the steel surface and hard sand particles. The results presented in the article are important not only for belt conveyor elements but also for other machine parts where it is desirable to reduce abrasive wear.

THE IMPACT OF PADDING WELD SHAPE OF AGRICULTURAL MACHINERY TOOLS ON THEIR ABRASIVE WEAR

Tribologia ◽  
2020 ◽  
Vol 290 (2) ◽  
pp. 55-62 ◽  
Author(s):  
Dawid ROMEK ◽  
Jarosław SELECH ◽  
Dariusz ULBRICH ◽  
Agata FELUSIAK ◽  
Piotr KIERUJ ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Abrasive Wear ◽  
Laboratory Tests ◽  
Welding Process ◽  
Agricultural Machinery ◽  
Weld Shape ◽  
Second Stage ◽  
Coated Electrode ◽  
The Impact

The paper presents laboratory tests results of wear in the abrasive mass of cultivator coulters subjected to coated electrode pad welding. In the first stage of the test, one type of electrode was used and a padding weld was applied to the coulter surface in three different shape variants (perpendicular, parallel to the abrasive mass stream and V-shaped). The lowest abrasive wear was obtained for samples with a padding weld deposited perpendicularly to the abrasive mass stream. Therefore, in the second stage of the research, this padding weld shape was selected and made using three different electrodes. Tests of abrasive wear both in the first and the second stage of the experiment were carried out at a distance of 100 km by the "rotating bowl unit" method. Both the direction of the application of the padding weld (shape) and the chemical composition of the electrode used in the pad welding process significantly increased the resistance to abrasive wear compared to coulters whose surface has not been welded.

Increasing in wear resistance of excavating machine elements

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Thermomechanical Treatment ◽  
Cold Work ◽  
Hadfield Steel ◽  
Outer Side ◽  
Viii And Ix ◽  
Machine Elements ◽  
The Impact

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.

scholarly journals Water Influence on the Uniaxial Tensile Behavior of Polytetrafluoroethylene-Coated Glass Fiber Fabric

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 846
Author(s):  
Hastia Asadi ◽  
Joerg Uhlemann ◽  
Natalie Stranghoener ◽  
Mathias Ulbricht
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Operation Time ◽  
Uniaxial Tensile ◽  
Membrane Structures ◽  
Strength Deterioration ◽  
Coated Glass ◽  
Reversible Loss ◽  
The Impact ◽  
Loss Of Strength

Polytetrafluoroethylene (PTFE)-coated glass fiber fabrics are used for long-lasting membrane structures due to their outstanding mechanical properties, chemical stabilities, and satisfying service life. During their operation time, different environmental impacts might influence their performance, especially regarding the mechanical properties. In this contribution, the impact of water on the tensile strength deterioration was assessed experimentally, providing evidence of considerable but partially reversible loss of strength by up to 20% among the various types of investigated industrially established fabrics.

scholarly journals Experimental studies on the possibility of using a pulsed laser for spot welding of thin metallic foils

2020 ◽  
Vol 10 (1) ◽  
pp. 674-680
Author(s):  
Piotr Sęk
Keyword(s):  
Experimental Studies ◽  
Pulsed Laser ◽  
Welding Process ◽  
Pulse Mode ◽  
Weld Strength ◽  
Spot Welds ◽  
Butt Welding ◽  
Strength Tests ◽  
Metallic Foils ◽  
The Impact

AbstractThe purpose of the experiment was to study the influence of the laser beam in pulse mode on metallic foils in order to obtain a spot weld. The welding process was carried out using the overlap weld method, using spot welds in various quantities. The Nd - YAG BLS 720 pulsed laser was used to conduct the experiment. The impact of the number of spot welds on the value of force needed to break the sample was examined. A number of measurements were carried out to determine the best process parameters. Butt welding and overlap welding were also performed using a continuous weld consisting of spot welds. Weld strength tests were performed to select the most appropriate parameters for the process under consideration.

scholarly journals Speeding Up the Write Operation for Multi-Level Cell Phase Change Memory with Programmable Ramp-Down Current Pulses

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 461 ◽  
Author(s):  
Chenchen Xie ◽  
Xi Li ◽  
Houpeng Chen ◽  
Yang Li ◽  
Yuanguang Liu ◽  
...  
Keyword(s):  
Phase Change ◽  
Current Source ◽  
Phase Change Memory ◽  
Operation Time ◽  
Access Time ◽  
Fully Differential ◽  
Current Pulses ◽  
Multi Level ◽  
The Impact ◽  
Change Memory

Multi-level cell (MLC) phase change memory (PCM) can not only effectively multiply the memory capacity while maintaining the cell area, but also has infinite potential in the application of the artificial neural network. The write and verify scheme is usually adopted to reduce the impact of device-to-device variability at the expense of a greater operation time and more power consumption. This paper proposes a novel write operation for multi-level cell phase change memory: Programmable ramp-down current pulses are utilized to program the RESET initialized memory cells to the expected resistance levels. In addition, a fully differential read circuit with an optional reference current source is employed to complete the readout operation. Eventually, a 2-bit/cell phase change memory chip is presented with a more efficient write operation of a single current pulse and a read access time of 65 ns. Some experiments are implemented to demonstrate the resistance distribution and the drift.

Properties of the Electro-Spark Deposited Coatings - Technology and Applications

2015 ◽  
Vol 818 ◽  
pp. 61-64 ◽  
Author(s):  
Norbert Radek ◽  
Jozef Bronček ◽  
Peter Fabian ◽  
Jacek Pietraszek ◽  
Krzysztof Antoszewski
Keyword(s):  
Wear Resistance ◽  
Powder Metallurgy ◽  
Carbon Steel ◽  
Abrasive Wear ◽  
Hot Pressing ◽  
Abrasive Wear Resistance ◽  
Roughness Analysis ◽  
Ceramic Electrodes ◽  
Machine Parts ◽  
Wear Coatings

The paper is concerned with the performance properties of electro-spark deposited coatings, which were determined basing on microstructural and roughness analysis and application tests. The studies were conducted using of the tungsten carbide-ceramic electrodes produced by the powder metallurgy hot pressing route. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of an EIL-8A. These coatings are likely to be applied to increase the abrasive wear resistance of tools and machine parts.

Explosive Welding of SS304 and Al6061 Using Copper as Interlayer – Development of Trial Methodology and its Optimisation

2015 ◽  
Vol 830-831 ◽  
pp. 306-309
Author(s):  
Niraj Srivastava ◽  
Abhishek Upadhyay ◽  
Sandeep Kumar ◽  
Diva ◽  
Jaspreet Singh ◽  
...  
Keyword(s):  
Explosive Welding ◽  
Welding Process ◽  
Al Alloy ◽  
Flyer Plate ◽  
Trial Methodology ◽  
Al 6061 ◽  
Velocity Of Detonation ◽  
Copper Interlayer ◽  
Weldability Window ◽  
The Impact

This paper explains the technique of explosive welding for joining SS304 and Al 6061 using Copper interlayer. The joining was done in two stages. In the first stage SS304 (thickness: 20 mm) was joined to Copper (thickness: 3mm). Second stage involved joining of SS-Cu plate to Al 6061 (thickness: 8 mm).The paper presents detailed discussion on important parameters required for explosive welded process. The most important parameter is minimum and maximum flyer plate velocity required for creating the impact. Collision angle and angle of impact are also discussed. Another important parameter is the Velocity of detonation (VOD) of explosive to be used. The explosives used have VOD of the order of 2500 m/s and 1600 m/sec. Since the explosive welding process involves formation of jet between two surface, therefore surface conditions of the base and flyer plate like its flatness, roughness and cleanliness which are very critical for proper joining have been discussed in this paper. Chisel test (which is considered to be most rugged test) was conducted on the joint. The test confirmed successful joining.The paper explains how use of trimonite expands the weldability window in comparison to NGU when used for direct SS to Al alloy welding.It also compares the results obtained by use of two different powder explosives to obtain the same tri-layered plate via two different routes. The results are particularly interesting because both the explosives have substantial difference in their properties such as Velocity of Detonation, Gurney Characteristic Velocity, density and homogeneity which can be used as advantages from different angles of views.

Microstructure and mechanical properties of ADC12/6063-T6 aluminum alloy butt joint achieved by metal inert gas groove welding

2018 ◽  
Vol 233 (10) ◽  
pp. 2120-2124
Author(s):  
Ye Wang ◽  
Mi Zhao ◽  
Hongyu Xu ◽  
Maoliang Hu ◽  
Zesheng Ji
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Butt Joint ◽  
Inert Gas ◽  
Butt Joints ◽  
Arc Welding Process ◽  
The Impact ◽  
Silicon Particles

Metal inert gas arc welding process was implemented to join 6063T6 wrought alloy and ADC12 die-casting alloy using ER4047 filler metal. The microstructure of the weld seam and weld interface was investigated. The bonding strength of the butt joints was tested by Charpy U-notch impact test and tensile test. The results showed that a sound welding butt joint with finely silicon particles and excellent mechanical properties was formed, and the size of the silicon particles was nearly 2 μm. Compared with 6063T6 wrought alloy, the impact absorbing energies and the tensile strengths of the butt joint were higher and reached 1.173 kJ/cm2 and 205 MPa, respectively, and the fractures of all tensile specimens occur at the 6063T6 aluminum.

scholarly journals Postoperative Hypoalbuminemia: Prevalence, Risk Factors, Association with Postoperative Pneumonia in Brain Tumors Patients Undergoing Craniotomy

2021 ◽  
Author(s):  
Da-wei Zhao ◽  
Xu-yang Zhang ◽  
Kai-yan Wei ◽  
Yi-bin Jiang ◽  
Dan Liu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Operation Time ◽  
Postoperative Pneumonia ◽  
Tumor Surgery ◽  
Regression Analyses ◽  
Brain Tumor Surgery ◽  
The Impact ◽  
Preoperative Albumin

Abstract Hypoalbuminemia is associatied with poor outcome in patients undergoing surgery intervention. The main aim for this study was to investigate the incidence and the risk factors of postoperative hypoalbuminemia and assessed the impact of postoperative hypoalbuminemia on complications in patients undergoing brain tumor surgery. This retrospective study included 372 consecutive patients who underwent brain tumors surgery from January 2017 to December 2019. The patients were divided into hypoalbuminemia (< 35 g/L) and non-hypoalbuminemia group (≥ 35 g/L) based on postoperative albumin levels. Logistic regression analyses were used to determine risk factors. Of the total 372 patients, 333 (89.5%) developed hypoalbuminemia after surgery. Hypoalbuminemia was associated with operation time (OR 1.011, P < 0.001), preoperative albumin (OR 0.864, P = 0.015) and peroperative globulin (OR 1.192, P = 0.004). Postoperative pneumonia had a higher incidence in patients with than without hypoalbuminemia (41.1% vs 23.1%, P = 0.029). The independent predictors of postoperative pneumonia were age (OR 1.053, P < 0.001), operation time (OR 1.003, P = 0.013) and lower postoperative albumin (OR 0.946, P = 0.018). Postoperative hypoalbuminemia has a higher incidence with the increase of operation time, and is associated with postoperative pneumonia in patients undergoing brain tumor surgery.

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