摘要
采用原位的机械研磨化学镀方法在碳钢上制备出Ni-P镀层。原位的机械研磨处理方法是在化学镀溶液中加入试样以及直径为2～3 mm的玻璃小球,在化学镀的过程中,将小球与试样用搅拌器完全搅起,小球与试样的接触就像撞击的过程。机械研磨化学镀后,镀层由非晶向晶态发生转变,镀层为Ni的多晶结构,镀层颗粒细化并且光滑平整。与传统化学镀非晶Ni-P镀层相比,镀层硬度、耐蚀性都相应提高。400℃进行退火1 h后,在传统化学镀Ni-P镀层中有孔洞和裂纹出现,而在机械研磨化学镀Ni-P镀层中没有出现孔洞和裂纹。在传统的Ni-P镀层中发现裂纹,说明在镀层表面形成了拉应力,表明在非晶晶化的过程中体积发生了收缩。由于机械研磨化学镀Ni-P镀层已经发生了晶化,其镀层密度高于传统镀层,在热处理过程中,机械研磨化学镀Ni-P镀层的体积变化比传统化学镀Ni-P镀层的体积变化要小,因此没有裂纹产生。热处理后,机械研磨化学镀Ni-P镀层中Ni和Ni3P的晶粒尺寸都比传统镀层中的小,因而,经过机械研磨处理,镀层的硬度、耐蚀性和耐磨性将得到很大提高。机械研磨化学镀Ni-P镀层性能的提高预示着这项新的技术将会在工业上得到广泛的应用。
A mechanically assisted electroless（MAE）-plating technique was developed to deposit Ni-P coatings on carbon steel.The mechanical in-situ treatment was carried out with glass balls of 2~3 mm diameter in stirred chemical solution,like a penning process.The coatings were Ni-polycrystalline and had fine grained structure and smooth surfaces.The hardness and corrosion resistance of the novel coatings were considerably improved compared with the conventional electroless（CE）-plated Ni-P coatings,which were amorphous.After heat treatment at 400 ℃ for one hour,cores and cracks were observed in the CE-plated Ni-P coating,while no holes and cracks appeared in the MAE-plated Ni-P coating.The holes and cracks in traditional coating indicated that tensile stress formed and the volume contracted.Because of the crystallization,the density is higher than that of traditional coating,in the process of heat treatment;the volume change in MAE-plated Ni-P coating was smaller than that of traditional coating.After heat treatment,the grain size was small,so the hardness,corrosion resistance were improved greatly.The improved properties of the MAE-plated Ni-P coatings demonstrated the advantages of this novel technique.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2011年第2期189-195,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金资助项目(50671006)
关键词
机械研磨化学镀Ni-P镀层
晶化
耐蚀性
硬度
mechanically assisted electroless plating
Ni-P coating
crystallization
corrosion resistance
microhardness
