脉冲复合镀层Ni-W-P-SiC和RE-Ni-W-P-SiC的组织与相结构分析

运用X射线衍射仪、电子探针X射线能谱仪等手段分析研究了Ni-W-P-SiC和RE-Ni-W-P-SiC脉冲复合镀层的组织结构.结果表明,Ni-W-P-SiC和RE-Ni-W-P-SiC两种脉冲复合镀层表面比相应直流镀层光滑平整细腻得多,脉冲参数不同会得到表面平整程度和粒度不同的镀层,稀土的加入使RE-Ni-W-P-SiC复合镀层比Ni-W-P-SiC复合镀层晶粒更细小、截面更均匀;同时热处理温度和时间对镀层的截面形貌也有影响,Ni-W-P-SiC、RE-Ni-W-P-SiC脉冲镀层在镀态时都是非晶态结构,随着热处理温度的升高,两脉冲复合镀层的非晶态形态逐渐减弱,镀层逐渐向晶态转变,Ni3P相的衍射峰逐渐加强,且不断出现新相的特征峰;稀土元素的加入对脉冲镀层在镀态和热处理时相结构有一定程度影响.

Microstructures and Phase Structure of Pulse Electrodeposited Ni-W-P-SiC and RE-Ni-W-P-SiC Composite Coatings

Microstructure of pulse electrodeposited Ni-W-P-SiC and RE-Ni-W-P-SiC composite coatings was analyzed by means of EPMA-1600 electron probe,3015 XRD patterns,et al.The results show that the surface of pulse electrodeposited Ni-W-P-SiC and RE-Ni-W-P-SiC composite coating is much smoother than that of direct current coating,and different pulse parameters result in different surface roughness and particle size.Fine particle and uniform section are obtained with the addition of rear earth elements.Heat treatment temperature and time also have effects on the section morphology of the deposited coatings: Ni-W-P-SiC and RE-Ni-W-P-SiC as-deposited coatings are amorphous,which gradually weaken and transform to crystal with increasing the heat treatment temperature.At the same time,the Ni3P diffraction peak is strengthening and the characteristic peak of new phase appears unceasingly.The addition of rear earth elements has some influence on the microstructure of the pulse composite coatings.