9月1号
家常冷面
腹轮
Trans.Nonferrous Met.Soc.China30(2020)333−343
Improving tribological and thermal properties of Al alloy using CNTs and Nb nanopowder via SPS for power transmission conductor
怎样写好行书Chika O.UJAH1,Patricia POPOOLA1,Olawale POPOOLA2,Victor AIGBODION1,3,Philip OLADIJO4,5望洞庭教案
1.Department of Chemical,Metallurgical and Materials Engineering,
Tshwane University of Technology,Pretoria0001,South Africa;
2.Department of Electrical Engineering,Tshwane University of Technology,Pretoria0001,South Africa;
3.Department of Metallurgical and Materials Engineering,University of Nigeria,Nsukka410001,Nigeria;祝贺升职的祝福语
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4.Department of Chemical,Materials and Metallurgical Engineering,
Botswana International University of Science and Technology,Palapye12345,Botswana;
5.Department of Mechanical Engineering,University of Johannesburg,Johannesburg2000,South Africa
Received23March2019;accepted25November2019
Abstract:This study aimed at improving the tribological and thermal properties of Al alloy using CNTs and Nb nanopowder as reinforcements and spark plasma sintering(SPS)as the fabrication method.The SPS was conducted at 630°C,30MPa,10min,and200°C/min.The tribology test was run with ball-on-disc tribometer using steel ball as the counter body.And the thermal test was procesd
with thermogravimetric analyzer(TGA)and lar flash apparatus (LFA).Results showed that the addition of8wt.%CNTs and8wt.%Nb reinforcements respectively decread the coefficient of friction(COF)of the composite by79%.The wear volume of the composite was decread by23%,and so was the wear rate.However,the thermal conductivity of the composite was equally improved by44%.The tribology improvement was stimulated by a C film generated by CNTs and a protective Nb2O5formed by Nb nanopowder.The thermal conductivity was improved by the grain refining property of Nb and the high thermal conductivity of CNTs. Therefore,the results indicated that Al−CNTs−Nb composite is a robust material for high transmission conductor capable of reducing sag and ensuring the durability of the composite.
Key words:tribology;thermal conductivity;spark plasma sintering;Al−CNTs−Nb composite;coefficient of friction
1Introduction
养水獭One of the most difficult challenges encountered in power transmission is conductor sag which is primarily due to the inelastic expansion of the conductor as a result of high thermal and electrical loading.To forestall this,conductors are made of central cores synthesized with materials of good ther
mal conductivity,low coefficient of thermal expansion(CTE)and high tribological properties.So,rearches on developing a robust material for the conductor and its core capable of operating at a high temperature with very low sag are under way.Monolithic Al1000alloy posss light mass,good corrosion and electrical properties necessary for power transmission conductor,but it is poor in tribological and thermal characteristics. To boost this alloy,CNTs which have thermal conductivity of3kW/(m·K),low CTE,high strength and good wear resistance[1]should rve as a good reinforcement.Moreover,Nb is a good grain refiner,a superconductor,and a fracture toughening additive[2]which could contribute immenly to the enhancement of Al alloy for the purpo in question.In this modern era of high energy cost and demand,conrvation of energy plays a paramount role in the production process.
Corresponding author:Chika O.UJAH;E-mail:omega. DOI:10.1016/S1003-6326(20)65216-5
