Development of CuNiSi-x alloy catenary parts by thermomechanical processing for railway applications

Koç, Ömer Faruk
Electrical conductivity together with some other mechanical properties like strength is needed for catenary systems in railway applications. In recent years, copper and its alloys especially the ones with Ni and Si which can mostly satisfy these mechanical needs are extensively researched. For this reason, uses of CuNiSi base alloys have become widespread. In the research study CuNiSi base alloys were put through several treatments to improve their properties. These treatments were basically melting and casting into permanent molds, solutionizing for appropriate temperatures, cold/hot working operations and heat treatments at different temperatures. Furthermore, microstructural analyses mainly grain size determination was carried out. In order to improve strength and shapeability of alloys, also grain size of 20-30μm was aimed. Throughout the study, scanning electron microscopy analysis, X-Ray diffraction analysis, hardness tests, bending tests, electrical conductivity tests were conducted. These tests and analyses were done to observe effects of different treatments on mechanical properties. A production route for optimum mechanical properties was designed. Additionally, hardness measurements were recorded as significantly higher for alloys with additional alloying element (CuNiSi-CrFe) on the other hand electrical conductivity was measured to be lower. SEM analyses revealed precipitate formation in the structure explaining this hardness increase. Namely, highest hardness measured is 120HB and average electrical conductivity measured is 42 %IACS for alloy composition of Cu%2,23Ni%0,34Si alloy. Grain size of this alloy after thermomechanical processing is in the range of 20-30 m. On the other hand, highest hardness measured is 180 HBN and average electrical conductivity measured is 34 %IACS for optimized alloy composition with Fe and Cr addition such as Cu%2,4Ni %0,6Si+%0,45Cr,%0,15Fe. Again, grain size of this alloy after thermomechanical processing is about 20-30 m. 


Investigation of Au-Ag-Cu Alloy Electrodeposition to Electromechanical Systems
Çağan, Berkay; Erdoğan, Metehan; Yılmaz, Cemil; Yurdakul, Burak; Karakaya, İshak (2020-07-01)
Electromechanical systems, which provide electrical power and dataconnection between moving terminals require high conduction and erosionresistant surfaces. Transfers of electrical power and data are accomplishedby the contact of drum and brush wires. The simultaneous electrochemicaldeposition of desired Au-Ag-Cu alloy compositions, which can be used tocoat the brush wires, was investigated in this study. In the scope of the study,the static potential and cyclic voltammetry behaviors of gold, silver andcopp...
Liquid steel flow in continuous casting machine: Modelling and measurement
Yavuz, Mehmet Metin (Informa UK Limited, 2011-08-01)
Single phase (liquid steel) and two-phase (liquid steel and argon bubbles) three-dimensional computational fluid dynamic and heat transfer models were developed for the continuous casting machines of ArcelorMittal. The computational domains include tundishes, slide gates, submerged entry nozzles and moulds. The effects of buoyancy, tundish design, tundish practices, nozzle design and caster practices on flow structure were investigated. Mathematical modelling is discussed in detail. In addition, submeniscus...
Design of a Piezoelectric Ultrasonic Motor for Micro-Robotic Application
Akın, Tayfun; Başaran, Dilek; Erden, Abdülkadir (null; 2002-09-05)
In a piezoelectric ultrasonic motor, exciting at least two orthogonal mechanical vibration modes of the composite stator using single or orthogonal multiple high frequency AC signals generates a mechanical vibration on the stator surface. The rotor is pressed against the stator's surface and a rotation is produced by frictional interaction between the touching stator and rotor surfaces. Piezoelectric ultrasonic motors, which have superior characteristics like; high torque at low speed, frictional locking at...
Investigation of Self-Excited Ultrahigh Speed Induction Generators for Distributed Generation Systems
Jardan, Rafael K.; Varga, Zoltan; Nagy, Istvan (2011-09-10)
Application of ultra high speed induction generators (IG) in a system developed for utilization of renewable and waste energies that can be applied in Distributed Generation System is presented. The energy conversion is made by a turbine-generator set. For the electromechanical energy conversion application of special high speed induction generators has been studied and described in the paper. The design and analysis of the system are relied on computer simulation techniques verified by test results.
Refinement of primary carbides in AISI DC 53 cold work tool steel by thin section copper permanent mould casting and water atomization
ÇARDAKLI, İSMAİL SEÇKİN; Kalkanlı, Ali (Informa UK Limited, 2019-05-01)
In this study, as alternative methods to conventional production methods involving thin section copper permanent mould casting (fast solidification) and water atomization (rapid solidification) of AISI DC 53 cold work tool steel have been investigated. Thin slabs obtained by copper mould casting was homogenized at 1150 degrees C for one hour and then hot rolling was be applied. After hot rolling, conventional heat treatment have been applied to thin slabs. The same heat treatment procedure have been perform...
Citation Formats
Ö. F. Koç, “Development of CuNiSi-x alloy catenary parts by thermomechanical processing for railway applications,” M.S. - Master of Science, Middle East Technical University, 2017.