Microstructure and properties of ultra-fine tungsten heavy alloys prepared by mechanical alloying and electric current activated sintering

• Published in: Transactions of Nonferrous Metals Society of China Vol. 20; no. 3; pp. 443 - 449
• Main Author: 李小强 辛红伟 胡可 李元元
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2010; National Metallic Materials Net-shape Forming Engineering Research Center,South China University of Technology, Guangzhou 510640, China
• Subjects: 93W-4Ni-2Co-1Fe alloy; Alloys; Creep rupture strength; Densification; Density; Electric current; electric current activated sintering; Grain size; mechanical alloying; Sintering; Sintering (powder metallurgy); Tungsten base alloys; 合金性能; 微观结构; 机械合金化; 活化烧结; 脉冲电流; 钨合金; mechanical alloying; 93W-4Ni-2Co-1Fe alloy; electric current activated sintering
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(09)60160-6

The microstructure and properties of the 93W-4Ni-2Co-1Fe（mass fraction,%） tungsten heavy alloys prepared by mechanical alloying and electric current activated sintering from mixed elemental powders were investigated.After 15 h milling,the average W grain size in the powders is decreased to 120 nm.For the powders milled for 15 h,the density,hardness and transverse rupture strength of the alloys sintered only by an intensive pulse electric current are the maximum.When the total sintering time keeps constant,the properties of the sintered alloys can be obviously improved by optimizing the sintering time of pulse-and constant-currents.A bulk ultrafine alloy with an average W grain size of about 340 nm can be obtained by sintering 15 h-milled powders in a total sintering time of 6 min.The corresponding sintered density,hardness and transverse rupture strength reach 16.78 g /cm3,HRA84.3 and 968 MPa,respectively.