Z.C. Guo
,
X.Y. Zhu
金属学报(英文版)
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 increasing
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.
关键词:
pulse frequency
,
null
,
null
赵广宏
,
何业东
材料热处理学报
采用高频脉冲电源在纯铜基材上以等离子电沉积技术制备出了金属镍镀层,研究了高频脉冲频率以及占空比变化对等离子镀镍层结构和性能的影响。对镀层进行了SEM,显微硬度以及划痕结合力的表征。结果表明,随着高频脉冲频率和占空比的增加,镀层表面的熔融态形貌逐渐减少,镀层逐渐变得致密,表面硬度与结合力值也相应提高。通过讨论脉冲电源的能量作用方式,分析了频率及占空比对等离子电沉积镍层表面结构及性能的影响规律。
关键词:
等离子电沉积
,
脉冲频率
,
占空比
,
镀镍层
,
表面结构
许志显
,
陈吉
,
孙彦伟
,
陈晓明
,
常季
腐蚀科学与防护技术
doi:10.11903/1002.6495.2014.286
利用改变脉冲频率,采用脉冲电镀法在黄铜片基体上制备出纳米晶Fe-Ni-Cr合金镀层.采用SEM和EDS对镀层的表面形貌和成分进行表征,采用XRD对镀层的结构进行表征,采用电化学工作站对镀层的极化曲线和电化学阻抗进行表征.结果表明:当脉冲频率为5000 Hz时,镀层的表面较为平整,成分稳定,晶粒尺寸约为12nm,镀层在3.5％NaC1溶液的自腐蚀电位约为-200 mV,自腐蚀电流密度约为0.12 μA/cm2,电荷转移电阻约为2500 Ω/cm2.频率的改变能引起镀层晶粒尺寸的改变,合适的频率有利于合金的形核,显著改善了镀层的耐蚀性能.
关键词:
脉冲频率
,
Fe-Ni-Cr
,
晶粒尺寸
,
耐蚀性
胡仕成
,
沈剑
,
孔祥奎
,
彭聪
,
张万高
有色金属工程
doi:10.3969/j.issn.2095-1744.2016.03.008
通过控制脉冲电流的频率及处理时间,研究脉冲电流对纯铝凝固组织及性能的影响.结果表明,脉冲电流能使纯铝的凝固组织由柱状晶转变为等轴晶,脉冲频率为50 Hz时,组织细化效果达到最佳,截面等轴晶面积比率最大,横向截面等轴晶平均面积最小.处理后的试件布氏硬度、抗拉强度、屈服强度、延伸率分别提高9.79％、13.93％、9.33％、10.37％.
关键词:
脉冲电流
,
脉冲频率
,
晶粒细化
,
趋肤效应
