ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Ultrafine grain WC hardmetals were manufactured successfully from mixed powders ofnominal composition of WC-6Co-1.5Al(wt%). To manufacture bulk ultrafine grain WC alloys,nanocrystalline WC powders as precursor were prepared for sintering from the mixed commerciallyavailable powders by high energy milling of 15 h. Then the electrical current sintering process ofthe milled powders was further studied. Experimental results showed that the density, hardness andtransverse rupture strength of the sintered alloys reached 14.224 g/cm3, HRA 94 and 1660 MPa,respectively, by a appropriate coupling of pulse- and subsequent constant-current sintering and withthe total sintering time of 6 min. It seemed difficult to obtain desirable sintered hardmetal by asingle type of electric current sintering. However, the application of intensive pulse electric currentwas favorable to sintering, although it was difficult to achieve good WC alloys only by the pulseelectric current sintering. A higher density WC alloy could be prepared by enlarging the electriccurrent when only constant electric current was applied to sinter the milled powders. Unfortunately,the WC grains substantially coarsened concurrently so that the mechanical properties of the assintered alloy decreased obviously
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.359-360.409.pdf
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