ISSN:
1662-8985
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:
The hardness, wear rates, phase structure and morphologies of DC(direct current) andPC(pulse current )electrodeposited Ni-W-P-SiC, RE-Ni-W-P-SiC, RE-Ni-W-P-SiC-MoS2 and RENi-W-P-SiC-PTFE composite coatings are studied. The results indicate that the hardness of pulsecomposite coatings is higher than that of DC composite coatings, but the hardness of RE-Ni-W-PSiC-PTFE composite coating is lower. The hardness of the four kinds of composite coatingsincreases with the rise of heat treatment temperature and reaches the highest value at 400°C,thereafter, the hardness begins to decrease. The hardness of RE-Ni-W-P-SiC composite coating isthe highest when duty cycle is at 0.6 and 0.8 and pulse frequency is at 50Hz and the hardness ofRE-Ni-W-P-SiC composite coatings at 0.8 is higher than that at 0.6; the wear rates of Ni-W-P-SiC,RE-Ni-W-P-SiC, and RE-Ni-W-P-SiC-PTFE pulse composite coatings are lower than that of DCcomposite coatings and the wear rates of RE-Ni-W-P-SiC-MoS2 and RE-Ni-W-P-SiC-PTFEcomposite coatings are the lowest. Ni-W-P-SiC and RE-Ni-W-P-SiC pulse composite coatings areamorphous, and RE-Ni-W-P-SiC-MoS2 pulse composite coating is mixture, but the RE-Ni-W-PSiC-PTFE composite coating is crystal as–deposited. The crystalline grain size of PC compositecoatings is smaller than that of DC composite coatings, and the addition of rare earth into thecoatings can make crystalline grains become fine, all kinds of grains in the coatings distributeequably and there are not cracks on the surface and in the sections
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.41-42.329.pdf
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