A high-performance copper-based brake pad for high-speed railway trains and its surface substance evolution and wear mechanism at high temperature

Wear ◽  
2020 ◽  
Vol 444-445 ◽  
pp. 203182 ◽  
Author(s):  
Peng Zhang ◽  
Lin Zhang ◽  
Dongbin Wei ◽  
Peifang Wu ◽  
Jingwu Cao ◽  
...  
Keyword(s):  
High Temperature ◽  
Wear Mechanism ◽  
High Speed ◽  
High Performance ◽  
Brake Pad ◽  
High Speed Railway

scholarly journals Study on Wear and Fatigue Performance of Two Types of High-Speed Railway Wheel Materials at Different Ambient Temperatures

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1152
Author(s):  
Lei MA ◽  
Wenjian WANG ◽  
Jun GUO ◽  
Qiyue LIU
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Speed ◽  
Room Temperature ◽  
Lamellar Spacing ◽  
Wear Loss ◽  
High Speed Railway ◽  
Railway Wheel ◽  
Ambient Temperatures ◽  
Railway Wheels

The wear and fatigue behaviors of two newly developed types of high-speed railway wheel materials (named D1 and D2) were studied using the WR-1 wheel/rail rolling–sliding wear simulation device at high temperature (50 °C), room temperature (20 °C), and low temperature (−30 °C). The results showed that wear loss, surface hardening, and fatigue damage of the wheel and rail materials at high temperature (50 °C) and low temperature (−30 °C) were greater than at room temperature, showing the highest values at low temperature. With high Si and V content refining the pearlite lamellar spacing, D2 presented better resistance to wear and fatigue than D1. Generally, D2 wheel material appears more suitable for high-speed railway wheels.

scholarly journals Experimental Study of the Temperature Distribution in CRTS-II Ballastless Tracks on a High-Speed Railway Bridge

2020 ◽  
Vol 10 (6) ◽  
pp. 1980 ◽  
Author(s):  
Lei Zhao ◽  
Ling-Yu Zhou ◽  
Guang-Chao Zhang ◽  
Tian-Yu Wei ◽  
Akim D. Mahunon ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
High Speed ◽  
Railway Track ◽  
Vertical Temperature ◽  
High Speed Railway ◽  
Extreme High Temperature ◽  
Transverse Temperature ◽  
Temperature Test

To study the temperature distribution in the China Railway Track System Type II ballastless slab track on a high-speed railway (HSR) bridge, a 1:4 scaled specimen of a simply-supported concrete box girder bridge with a ballastless track was constructed in laboratory. Through a rapid, extreme high temperature test in winter and a conventional high temperature test in summer, the temperature distribution laws in the track on the HSR bridge were studied, and the vertical and transverse temperature distribution trend was suggested for the track. Firstly, the extreme high temperature test results showed that the vertical temperature and the vertical temperature difference distribution in the track on HSR bridge were all nonlinear with three stages. Secondly, the extreme high temperature test showed that the transverse temperature distribution in the track was of quadratic parabolic nonlinear form, and the transverse temperature gradient in the bottom base was significantly higher than that of the other layers of the track. Thirdly, the three-dimensional temperature distribution in the track on HSR bridge was a nonlinear, three-stage surface. Furthermore, similar regularities were also obtained in the conventional high temperature test, in which the temperature span ranges were different from those of the extreme high temperature test. In addition, the conventional high temperature test also showed that under the natural environment conditions, the internal temperature gradient in the track layers changed periodically (over a period of 24 h).

Investigation on Wear Behavior at High Temperature of Smooth and Bionic Non-Smooth Samples

2012 ◽  
Vol 157-158 ◽  
pp. 1628-1631
Author(s):  
Xiao Dong Yang ◽  
Zhuo Juan Yang ◽  
You Quan Chen
Keyword(s):  
High Temperature ◽  
Wear Mechanism ◽  
High Speed ◽  
Room Temperature ◽  
Wear Behavior ◽  
High Speed Steel ◽  
Wear Test ◽  
Test Method ◽  
Wear Characteristics ◽  
Pin On Disk

By using pin-on-disk wear test method, the wear behavior of W9Gr4V high speed steel with smooth and non-smooth concave samples which treated by laser texturing technology was investigated between room temperature and 500 . It was found that the anti-wear ability of the non-smooth concave samples was increased more than that of the smooth ones and the anti-wear ability of the non-smooth samples was evident than the smooth ones at temperature increasing. In this paper, the anti-wear mechanism of non-smooth concave samples and wear characteristics with smooth and non-smooth samples in high-temperature were analyzed.

Development of Test Rig for High-Speed Railway Rolling Bearings

2011 ◽  
Vol 101-102 ◽  
pp. 702-707 ◽  
Author(s):  
Zhao Dong Huang ◽  
Bo Qian Fan ◽  
Xiao Ping Ouyang ◽  
Ling Ling Xu ◽  
Zhi Gang Wang
Keyword(s):  
High Speed ◽  
High Performance ◽  
Rolling Bearing ◽  
Main Shaft ◽  
Heavy Vehicles ◽  
Test Rig ◽  
Rolling Bearings ◽  
Heavy Load ◽  
High Speed Railway ◽  
Mechanical Structure

The rolling bearing test rig for heavy vehicles often works under heavy load and high speed, thus it requires high performance for the main shaft and mechanical structure. In this paper a design of test rig for high-speed railway rolling bearings is presented, in which a new structure is adopted to reduce the load on the support bearings. The basic idea is to position the load in a way that they can be balanced by each other.

Durability Research for High-Performance Concrete Box Girder of High Speed Railway

2010 ◽  
Author(s):  
Jun-Qing Lei ◽  
Xin-Hua Zhong ◽  
Wu-Qin Wang
Keyword(s):  
Production Technology ◽  
High Speed ◽  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixture ◽  
Box Girder ◽  
High Speed Railway ◽  
Creep Properties ◽  
Shrinkage And Creep ◽  
Concrete Box Girder

Now the highspeed railway development is rapid in China. In view of the quality and the features of production technology of railway pre-concrete prefabricated box girder, the experiment researches five kinds of Pumping Concrete, which are composed of different significant slurry. Through researching the Mechanical, conductive, shrinkage and creep properties of specimen, it comes to a conclusion that the main compounding principle of low shrinkage, creep and high-performance concrete of railway box girder is adopting low water and right amount of mineral admixture.

scholarly journals Advances in Low Cost Silver-Containing Thick Film Conductors

1981 ◽  
Vol 9 (1) ◽  
pp. 67-85 ◽  
Author(s):  
Barry E. Taylor ◽  
John J. Felten ◽  
Samuel J. Horowitz ◽  
John R. Larry ◽  
Richard M. Rosenberg
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Thick Film ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
High Volume ◽  
Film Material ◽  
Advantages And Disadvantages ◽  
Thick Film Technology

Extensive use of thick film materials to manufacture resistor networks and hybrid integrated circuits has come about because of economic, processing and functional advantages over other technologies in the high volume production of miniaturized circuits. Inherent in the adoption of thick film technology for increasingly diverse applications has been the ability of thick film material suppliers to provide progressive performance improvements at lower cost concurrent with circuit manufacturer's needs. Since the first major commercial thick film adoption in the early sixties, when IBM adopted platinum gold conductors and palladium silver resistors in their 360 computers, rapid technological advances over the last decade have produced an increasing variety of hybrid circuits and networks. The wide adoption of thick film technology in all segments of the electronic industry has placed increasing demands on performance and processing latitude. This paper outlines the development of low cost silver-bearing conductors and describes the evolution of technology improvements to present day systems. The initial segment reviews the deficiencies of early Pd/Ag conductors, particularly solder leach resistance and degradation of soldered adhesion following high temperature storage, and focuses on the first Pd/Ag system which overcame these problems. Extension of this technology and subsequent improvements in both binders and vehicles to fulfill adhesion requirements to Al2O3substrates of varying chemistries and to meet demands for high speed printing are also described. The second segment gives an overview of the present understanding of thick film conductor composites from a mechanistic point of view. The various types of binder systems commonly employed in conductors are discussed in terms of how they effect a bond between the sintered metal and the substrate, and the advantages and disadvantages of each type. Metallurgical aspects of conductor/solder connections are considered and their effects on bond reliability following exposure to high temperature discussed. Rheological considerations of paste design are presented and related to printing performance. The final segment focuses on newer low cost, high performance material systems that have evolved over the past two years. The technologies of each system are reviewed in terms of metallurgy, binder and vehicle. Important functional properties are presented to illustrate cost/performance tradeoffs. Special emphasis is given to recently developed high Ag containing conductors which have outstanding soldered adhesion even after 1000 hours of storage at 150℃.

High Temperature Silicon Carbide Power Modules for High Performance Systems

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000159-000166 ◽  
Author(s):  
J. Hornberger ◽  
B. McPherson ◽  
J. Bourne ◽  
R. Shaw ◽  
E. Cilio ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
High Speed ◽  
High Performance ◽  
High Reliability ◽  
Extreme Environment ◽  
High Energy ◽  
Energy Applications ◽  
Power Modules ◽  
Reliability Systems

The demands of modern high-performance power electronics systems are rapidly surpassing the power density, efficiency, and reliability limitations defined by the intrinsic properties of silicon-based semiconductors. The advantages of silicon carbide (SiC) are well known, including high temperature operation, high voltage blocking capability, high speed switching, and high energy efficiency. In this discussion, APEI, Inc. presents two newly developed high performance SiC power modules for extreme environment systems and applications. These power modules are rated to 1200V, are operational at currents greater than 100A, can perform at temperatures in excess of 250 °C, and are designed to house various SiC devices, including MOSFETs, JFETs, or BJTs. One newly developed module is designed for high performance, ultra-high reliability systems such as aircraft and spacecraft, and features a hermetically sealed package with a ring seal technology capable of sustaining temperatures in excess of 400°C. The second module is designed for high performance commercial and industrial systems such as hybrid electric vehicles or renewable energy applications, implements a novel ultra-low parasitic packaging approach that enables high switching frequencies in excess of 100 kHz, and weighs in at just over 130 grams (offering ~5× mass reduction and ~3× size reduction in comparison with industry standard power brick packaging technology). It is configurable as either a half or full bridge converter. In this discussion, APEI, Inc. introduces these products and presents practical testing of each.

Decarburization Depth Control Technology Research and Application for U71Mn Rail

2013 ◽  
Vol 774-776 ◽  
pp. 1181-1185 ◽  
Author(s):  
Shu Hui Deng ◽  
Yong Deng
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Heating Furnace ◽  
Steel Grade ◽  
Heating Process ◽  
Control Technology ◽  
Technology Research ◽  
High Speed Railway ◽  
Depth Control ◽  
Protection Technology

U71Mn is the main steel grade for high-speed railway rails. In the production of U71Mn rail, its decarburization depth is the deepest, and the qualified percentage is lower than 60% for the requirement of less than 0.3mm of decarburization depth. On the basis of current heating furnace, the influence of different heating processes on the decarburization depth of U71Mn rail was studied, and the result shows that just optimization of heat process can not decrease greatly the decarburization depth. Therefore the high temperature anti-oxidation coating protection technology was carried out in the process of heating of U71Mn rail. Under the condition of protection heating and optimization of heating process, the decarburization depth of U71Mn rail decreases significantly, and the qualified rate reaches to more than 95% for the depth of less than 0.30mm, and 100% for the depth of less than 0.50mm.

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