STUDY ON PROPERTIES OF PULSE ELECTRODEPOSITED RE-Ni-W-P-SiC COMPOSITE COATINGS

• 出 处: Acta Metallurgica Sinica(English Letters)
• 发表日期: 2007年02期
• 关键词: hardness cycle crystalline reaches plating dispersed grains spectrometer have fi

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 lead 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.

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-WP-SiC composite coatings have been studied. The results indicate that pulse current can improve the deposition rate of RE-Ni-WP-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, while the RE content in the composite coatings increases with the increase of pulse frequency. SiC content decreases the duty cycle, W content reaches the highest value at, and P content reaches the highest value at r = 0.4; pulse current and RE can lead to smaller size of the crystalline grains; , the effects of different pulse frequency and duty cycle on the morphologies of RE-Ni-WP-SiC composite coatings are not obvious. The hardness of RE-Ni-WP-SiC composite coatings is the highest when the duty cycle is at 0.6 and 0.8 and pulse frequency is at 50 Hz. 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.