您目前所在的位置:首页 - 期刊简介 - 详细页面

铁道科学与工程学报

JOURNAL OF RAILWAY SCIENCE AND ENGINEERING

Vol. 19    No. 3    June 2009

[PDF Download]    [Flash Online]

    

Effect of ball milling time on microstructure and properties of
Laves phase NbCr2 alloys synthesized by hot pressing
XIAO Xuan(肖 璇)1, 2, LU Shi-qiang(鲁世强)1, HU Ping(胡 平)1, HUANG Ming-gang(黄铭刚)1, M. W. FU3

1. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. College of Electromechanical Engineering, Nanjing University of Aeronautical and Astronautics,
Nanjing 210016, China;
3. Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom,
Kowloon, Hong Kong, China

Abstract:Laves phase NbCr2 alloys with a composition of Nb-66.7Cr (molar fraction, %) were prepared by mechanical alloying and hot pressing. The microstructures and properties of the Laves phase NbCr2 alloys, prepared from elemental niobium and chromium powders under various ball milling time by hot pressing at 1 250 ℃ for 0.5 h, were investigated. The results indicate that if the ball milling time is longer than 40 h, the synthesizing reaction of Laves phase NbCr2 can be accomplished much sufficiently. Then the nearly full-dense Laves phase NbCr2 alloys can be prepared by hot pressing from ball milled powders with more than 40 h. The hot pressing sample with homogeneous and fine microstructure made from 40 h ball milled powders has the optimum microstructure and properties. It has a relative density of 98.1%, Vickers hardness of 11.4 GPa, compress strength of 1 981 MPa and fracture toughness of 4.82 MPa∙m1/2. The effect of fine grain toughening is fully realized.

 

Key words: Laves phase NbCr2; mechanical alloying; hot pressing; microstructure; mechanical properties

ISSN 1672-7029
CN 43-1423/U

主管:中华人民共和国教育部 主办:中南大学 中国铁道学会 承办:中南大学
湘ICP备09001153号 版权所有:《铁道科学与工程学报》编辑部
------------------------------------------------------------------------------------------
地 址:湖南省长沙市韶山南路22号 邮编:410075
电 话:0731-82655133,82656174   传真:0731-82655133   电子邮箱:jrse@mail.csu.edu.cn