(1. 福州大學(xué) 材料科學(xué)與工程學(xué)院，福州 350108；)
摘 要: 用脈沖電沉積方法制備表面平整光亮的納米晶Ni-Co-Fe合金鍍層。采用XRD、TEM、EDS、DSC和顯微硬度計(jì)分別研究納米晶Ni-Co-Fe合金鍍層的微觀結(jié)構(gòu)、化學(xué)成分、熱穩(wěn)定性及其硬度。結(jié)果表明：納米晶Ni-Co-Fe合金鍍層的晶體結(jié)構(gòu)為單相的面心立方結(jié)構(gòu)，其晶粒尺寸隨鍍層Co含量的增加而減小；合金鍍層的顯微硬度隨退火溫度的升高而提高，在300~375 ℃時(shí)達(dá)最大值，存在明顯的退火再?gòu)?qiáng)化，之后，隨著退火溫度的繼續(xù)升高明顯下降；當(dāng)鍍層在低于375 ℃退火時(shí)，晶粒長(zhǎng)大速度較慢；而當(dāng)鍍層在高于450 ℃退火時(shí)，晶粒迅速長(zhǎng)大，并呈現(xiàn)較強(qiáng)的(111)織構(gòu)。升溫速率為20 ℃/min時(shí)，納米晶Ni-Co-Fe合金鍍層的DSC結(jié)果顯示，晶粒長(zhǎng)大的峰值溫度隨鍍層Co含量的增加而升高。由Kissinger方程求得納米晶Ni-Co-Fe合金的晶粒長(zhǎng)大激活能隨鍍層Co含量的增加而增大。
關(guān)鍵字: 脈沖電沉積；納米晶；Ni-Co-Fe合金；熱穩(wěn)定性；激活能
Ni-Co-Fe alloy coatings
（1. College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China;
2. College of Marine Engineering, Jimei University, Xiamen 361021, China;
3. Department of Materials Science and Engineering, Fujian University of Technology, Fuzhou 350108, China）
Abstract:Nanocrystalline Ni-Co-Fe alloy coatings with smooth and bright surface were synthesized by pulsed electrodeposition. The microstructure, chemical composition, thermal stability and hardness of the coatings were studied by XRD, TEM, EDS, DSC and microhardness tester, respectively. The results reveal that the grain size of the nanocrystalline Ni-Co-Fe alloy coatings with FCC structure decreases with increasing the content of Co in the coatings. The microhardness of Ni-Co-Fe alloys increases with the increase of the annealing temperature after annealed at low temperatures, and reaches the peak value at 300−375 ℃, showing a significant hardening during annealing, and the hardness decreases with increasing the annealing temperature further. The grain grows slowly when the annealing temperature is lower than 375 ℃, while the rapid grain growth occurs during annealing above 450℃, showing a strong (111) texture. The DSC results obtained at the heating rate of 20 ℃/min show that the peak temperature value for the grain growth in nanocrystalline Ni-Co-Fe alloy coatings increases with increasing the content of Co in the coatings. The activation energy obtained from the Kissinger equation for the grain growth of Ni-Co-Fe alloy coatings increases with increasing content of Co in alloy coatings.
Key words: pulse electrodeposition; nanocrystalline; Ni-Co-Fe alloys; thermal stability; activation energy
