Fabrication and characterization of electrodeposited and magnetron-sputtered thin films

Abstract

The MnO-Zn thin films were fabricated by radio frequency (RF) magnetron sputtering and compared with pulse electrodeposition (PED) Zn thin films, doped with MnO and ZrO nanoparticles. Surface morphology, structural properties, chemical composition and corrosion resistance of these coatings were investigated by using scanning electron microscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, 3-D scanning interferometry and environmental chamber. Surface morphology and degree of crystallinity have different behaviours for different deposition methods. Pulse-coated films have polycrystalline structure with high surface roughness (R a ), whereas sputtered films are monocrystalline with reduced roughness (R a ). Corrosion tests of both RF sputter and PED films revealed that the distribution of corrosion products formed on the surface of sputter films were not severe in extent as in case of electrodeposited coatings. Results showed that the doping of ZrO nano-sized particles in Zn matrix and Mn-Zn composite films significantly improved the corrosion resistance of PED thin films. High electron mobility [7] and room temperature electrical conductivity of ZnO thin films make it perfect material for electronics equipment. Additional advantages of ZnO thin films and micro-nanostructure are abundance and non-toxicity of the ZnO material, low cast and quantum size effect. Depending on the application, tuning properties and band gap of ZnO is possible by doping another material such as: aluminum (Al), gallium (Ga), magnesium (Mg) and manganese (Mn).Also, there are advanced techniques of growing ZnO thin films and manufacturing such as metal organic chemical vapor deposition [8], radio frequency (RF) magnetron sputtering [9], sol-gel method and pulsed laser deposition [10]. Properties of ZnO thin films are investigated by using molecular beam epitaxy [11].Zinc plating is extensively used in corrosion protection of steel in many structural and general engineering applications. Zn coating on steel substrate provides with physical and mechanical properties as well as good corrosion resistance [12]. However, a high dissolution rate and low corrosion resistance limit the use of Zn coatings. In recent research and development activity on zinc-based alloy coatings, there is a growing interest in the use of Zn with various alloying elements like Mn and Zr. These elements (Mn and Zr) have an electrically, more negative potential (E°M n

A review of theoretical analysis techniques for cracking and corrosive degradation of film-substrate systems

“…The corrosion resistance, tribological performance and film characteristics have been reported [10][11][12][13]. The crystalline structure of film materials and thin film porosity are not subjects of this review as the phenomenon of corrosion diffusing species through micro cracks in thin films have been reported [14][15][16][17][18][19][20][21] in detail.…”

An Optimised Approach of Protecting and Sustaining Large Vehicle System

“…Sustainability 2015, 7,[16451][16452][16453][16454][16455][16456][16457][16458][16459][16460][16461][16462][16463][16464] Findings from this research helped to secure further grants including £2,560,600 for new conservation facility at Bovington, £20,000 for research into flow assisted corrosion failures, £23,000 for in-situ corrosion condition monitoring and £24,000 for corrosion health monitoring using wireless sensor technologies.…”

“…This article represents the synopsis of our wider research, which was designed to understand the prevailing failure mechanisms, measure and monitor the identified issues, establish their cause impact, in an effort to achieve an optimised approach to sustaining and protecting large vehicles sustainably and cost effectively beyond their original design life [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. This is the first evidence-based research carried out in this field and is directly linked to the development of a new sustainable sheltered facility incorporating environmental and corrosion condition monitoring systems, to produce further research and research grants.…”

Analysing the coupled effects of compressive and diffusion induced stresses on the nucleation and propagation of circular coating blisters in the presence of micro-cracks

“…Pervious research has analysed [36][37][38][39][40][41][42][43][44][45] coating substrate system without the inclusion of micro-cracks. However, this research aims to analyse the coupling effects of residual and diffusion induced stresses on blister growth in the presence of coating micro-cracks.…”