STUDY ON PROPERTIES OF PULSE ELECTRODEPOSITED RE-Ni-W-P-SiC COMPOSITE COATINGS
来源期刊：Acta Metallurgica Sinica2007年第2期
论文作者：R.D. Xu Z.C. Guo X.Y. Zhu
Key words：pulse frequency; duty cycle; electrodeposition; RE-Ni-W-P-SiC composite coating;
Abstract: The effects of pulse frequency f and duty cycle r on the deposition rate, composition, morphology,and hardness of pulse electrodeposited RE (rare earth)-Ni-W-P-SiC composite coatings have been studied. The results indicate that pulse current can improve the deposition rate of RE-Ni-W-P-SiC composite coatings; W, P, and SiC contents in the coating decrease with the increase of pulse frequency and reach the lowest value at f =33Hz, whereas the RE content in the composite coatings increases with the increase of pulse frequency. SiC content decreases with the increase of duty cycle, W content reaches the lowest value, and P content reaches the highest value at r=0.4; pulse current and RE can lend to smaller size of the crystalline grains; however, the effects of different pulse frequency and duty cycle on the morphologies of RE-Ni-W-P-SiC composite coatings are not obvious. The hardness of RE-Ni-W-P-SiC composite coatings is the highest when the duty cycle is at 0.6 and 0.8 and pulse frequency is at 50Hz. At the same pulse frequency, the hardness of RE-Ni-W-P-SiC composite coatings at r=0.8 is higher than that at r=0.6.
R.D. Xu1，Z.C. Guo1，X.Y. Zhu1
(1.Faculty of Materials and Metallurgical Engineering, Kunming University of Science and Technology,Kunming 650093, China)
Abstract:The effects of pulse frequency f and duty cycle r on the deposition rate, composition, morphology,and hardness of pulse electrodeposited RE (rare earth)-Ni-W-P-SiC composite coatings have been studied. The results indicate that pulse current can improve the deposition rate of RE-Ni-W-P-SiC composite coatings; W, P, and SiC contents in the coating decrease with the increase of pulse frequency and reach the lowest value at f =33Hz, whereas the RE content in the composite coatings increases with the increase of pulse frequency. SiC content decreases with the increase of duty cycle, W content reaches the lowest value, and P content reaches the highest value at r=0.4; pulse current and RE can lend to smaller size of the crystalline grains; however, the effects of different pulse frequency and duty cycle on the morphologies of RE-Ni-W-P-SiC composite coatings are not obvious. The hardness of RE-Ni-W-P-SiC composite coatings is the highest when the duty cycle is at 0.6 and 0.8 and pulse frequency is at 50Hz. At the same pulse frequency, the hardness of RE-Ni-W-P-SiC composite coatings at r=0.8 is higher than that at r=0.6.
Key words:pulse frequency; duty cycle; electrodeposition; RE-Ni-W-P-SiC composite coating;
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