Coatings
·
2020
·Vol. 10
·期 2
·128
·
IF 2.436
Qingjun Zhu,Binbin Zhang,Xia Zhao,Binbin Wang
Given the corrosion tendency of the natural oxide film of aluminum alloys, micro arc oxidation (MAO) treatment is used as an efficient and economic method to enhance the corrosion resistance. However, irregular voids, pores, and micro cracks are easily formed during the MAO process, which are harmful to the anti-corrosion property of MAO coatings. In this paper, binary additives of electrolytes, including (NaPO3)6and H3BO3, were used to obtain MAO coatings with improved thickness and compact microstructures on 6061 aluminum alloys. The as-prepared coatings were investigated using a thickness meter, scanning electron microscope (SEM), X-ray diffractometer (XRD), and electrochemical impedance spectroscope (EIS). The results showed that the coordinated influence of the binary additives could change the discharge behaviors and micro morphologies of the MAO coatings compared to the base silicate electrolyte. A thicker and stronger MAO coating could be achieved, which was mainly composed of Al2O3phases. The EIS tests revealed that the corrosion current density of the obtained optimal MAO coating decreased by three orders of magnitude from 1.209 × 10−6A·cm−2to 2.981 × 10−9A·cm−2. We believe that the binary additive-enhanced MAO coatings could provide a promising anti-corrosion solution in various applications.
研究领域:
材料科学
·
表面工程
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
METALS AND MATERIALS INTERNATIONAL
·
2021
·Vol. 28
·期 8
·1981-1990
·
IF 3.642
Hong Hao,Min Ding
Abstract To meet the growing demand of technologies of high performance electronics, nano-solders have been widely developed. In the present study, Sn-Zn nano-amorphous particles with core–shell structure were synthesized by a chemical reduction method with NaBH4 as reduction agent and Polyvinylpyrrolidone (PVP) as a stabilizer. The size distribution and thermal behaviour of the as-synthesized nano-particles were controlled by the amount of PVP, whose concentration ranged from 3 to 30 wt%. And the change was comparatively confirmed by TEM, DSC and XRD analysis. The results revealed that PVP concentrations can not only regulate and control the size distribution of the nano-particles and the melting point, which could also change the ratio of amorphous shell to crystalline core in nanostructures. In addition, sintering behavior of this nano-solder soldering 6061 aluminum alloys and its corresponding mechanical properties were evaluated based on SEM, XRD and the shear tests. The results turned out the best bonding quality was obtained under the condition of the content of PVP is 10 wt%. The obtained shear strength was as high as 17.6 MPa, and the elemental composition of the thinner IMC layer was Al 2 Zn 3 , which revealed a good solderability property. The above analysis provided a new insight into the effects of PVP content on the interfacial reaction mechanism. This bonding technology was suitable for the electronic devices bonded at low temperature. Graphical Abstract
研究领域:
材料科学
·
焊接技术
·
纳米材料
·
电子封装
·
合金加工
✓ 已验证
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2021
·Vol. 54
·期 3
·218-230
·
IF 1.607
Lu Chen,Nan Tu,Qianyang Wei,Tao Liu,Chengzhi Li,Wenbo Wang,Jianhui Li,Hailin Lu
In this paper, graphene oxide/polyethylene glycol (GO/PEG) composite water-based lubricant was prepared by an ultrasonic dispersion method, and characterized and analyzed by Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The suspension performance of GO/PEG composite water-based lubricant in water was verified by static sedimentation and centrifugation, and then, the prepared GO/PEG composite water-based lubricant was added into 304 stainless steel and 6061 aluminum alloy, and the coefficient of friction (COF) curve, average COF value, average wear rate, corresponding photomicrographs of balls and disks after wear, and energy-dispersive spectrometer (EDS) elemental analysis were used to illustrate the lubrication effect and lubrication mechanism. The results show that the GO/PEG composite water-based lubricant possesses excellent suspension ability in water, and the average COF value and wear rate of GO/PEG composite water-based lubricant are reduced by 78.8% and 88.8%, respectively, compared with water lubrication. The excellent lubrication effect of GO/PEG composite water-based lubricant can effectively reduce the cold-welding and adhesive wear phenomenon, mainly because GO/PEG composite water-based lubricant first fills the uneven surface of friction mating to form a high-quality lubricating film and then because of the special space structure of GO and the low shear between GO layers and the synergistic lubrication effect of GO/PEG.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Lei Zhu,Wei Gao,Yuxin Wang
A self-lubricating AAO-Cu/Ni-P composite coating was deposited on the surface of 6061 aluminum alloy. An anodized intermediate layer (AAO) was introduced to enhance the adhesion and wear resistance of the coating. The microstructure, element distribution, and properties of the composite coating were comprehensively analyzed and contrasted with those of the traditional Ni-P coating pretreated by zinc immersion and the AAO/Ni-P coating. The outcomes indicated that the bonding strength of both the AAO/Ni-P and AAO-Cu/Ni-P coatings was notably improved compared to the traditional Ni-P coating. Unlike the AAO/Ni-P coating, the AAO-Cu/Ni-P coating displayed a significant enhancement in friction resistance due to its self-lubricating properties. Consequently, the friction coefficient was reduced by approximately 42.9 % and the volume wear decreased by 86.7 %. This research provides valuable insights into the friction and wear mechanisms of AAO-Cu/Ni-P composite coatings, offering technical support for the development of high-performance aluminum alloys.
研究领域:
材料科学
·
表面工程
·
机械工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）