For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current （DC） and pulse curre...For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current （DC） and pulse current （PC） conditions. Copper deposits are strongly 〈220〉 textured in DC plating with and without chloride ion. While in PC condition, the predominant texture shifts from 〈220〉 to 〈200〉 as the chloride ion concentration exceeds 20 mg/l. The addition of ZrB2 particles enhances the cathodic polarization of copper deposition, which improves the growth of （111） plane. However, this improvement can be eliminated by further addition of chloride ion.展开更多
Copper-zirconium diboride （ZrB2） composite coatings were fabricated using pulse plating technique to acquire a new type of EDM （electro-discharge machining） electrode material. The effects of pulse parameters, i.e...Copper-zirconium diboride （ZrB2） composite coatings were fabricated using pulse plating technique to acquire a new type of EDM （electro-discharge machining） electrode material. The effects of pulse parameters, i.e., the average current density, the frequency and the duty cycle, on the incorporation of ZrB2 particles in the copper matrix were investigated. The amount＇of codeposited ZrB2 particles had a maximum at average current density of 3 A/din2 and increased with decreasing duty cycle as well as current frequency of the pulse current used for deposition. The hardness of the coatings increased with increasing ZrB2 percentage, whereas the incorporation of ZrB2 particles had little effect on the resistivity of the composites.展开更多
Direct current and pulse plating of copper-zirconium diboride （ZrB2） composites were studied and the effects of current density （DC） and pulse duty cycle （PC） on the EDM performance of the composites were invest...Direct current and pulse plating of copper-zirconium diboride （ZrB2） composites were studied and the effects of current density （DC） and pulse duty cycle （PC） on the EDM performance of the composites were investigated. With increasing current density, the effect of grain refinement on the electro-discharge machining （EDM） performance of the composites compensates that of the decrease of ZrB2 content in the composites, which improves the spark-resistance of the material. Under the same average current density and other experiment conditions, a lower duty cycle yields better EDM performance probably because more ZrB2 particles are incorporated in the composites in this condition. However, at a still lower duty cycle （10%）, the particle agglomeration and the microcracks of the copper matrix occur, which considerably deteriorate the spark-resistance of the composites.展开更多
基金This work was supported by the National Natural Science Foundation of China under grant No. 59935110.
文摘For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current （DC） and pulse current （PC） conditions. Copper deposits are strongly 〈220〉 textured in DC plating with and without chloride ion. While in PC condition, the predominant texture shifts from 〈220〉 to 〈200〉 as the chloride ion concentration exceeds 20 mg/l. The addition of ZrB2 particles enhances the cathodic polarization of copper deposition, which improves the growth of （111） plane. However, this improvement can be eliminated by further addition of chloride ion.
基金This work was supported by the National Natural Science Foundation of China under grant No. 59935110.
文摘Copper-zirconium diboride （ZrB2） composite coatings were fabricated using pulse plating technique to acquire a new type of EDM （electro-discharge machining） electrode material. The effects of pulse parameters, i.e., the average current density, the frequency and the duty cycle, on the incorporation of ZrB2 particles in the copper matrix were investigated. The amount＇of codeposited ZrB2 particles had a maximum at average current density of 3 A/din2 and increased with decreasing duty cycle as well as current frequency of the pulse current used for deposition. The hardness of the coatings increased with increasing ZrB2 percentage, whereas the incorporation of ZrB2 particles had little effect on the resistivity of the composites.
基金This work was financially supported by the National Natural Science Foundation of China (No. 59935110)the Science Founda-tion of Liaoning Province, China (No. 20062183).
文摘Direct current and pulse plating of copper-zirconium diboride （ZrB2） composites were studied and the effects of current density （DC） and pulse duty cycle （PC） on the EDM performance of the composites were investigated. With increasing current density, the effect of grain refinement on the electro-discharge machining （EDM） performance of the composites compensates that of the decrease of ZrB2 content in the composites, which improves the spark-resistance of the material. Under the same average current density and other experiment conditions, a lower duty cycle yields better EDM performance probably because more ZrB2 particles are incorporated in the composites in this condition. However, at a still lower duty cycle （10%）, the particle agglomeration and the microcracks of the copper matrix occur, which considerably deteriorate the spark-resistance of the composites.
