Browsing by Subject "Coating"

Now showing 1 - 3 of 3

Open Access
Micro tool design and fabrication: a review
(Elsevier, 2018) Oliaei, S. N. B.; Karpat, Yiğit; Davim, J. P.; Perveen, A.
Mechanical micromachining is considered as a cost-effective and efficient fabrication technique to produce three dimensional features and free-form surfaces from various engineering materials. Micro cutting tools are an essential part of mechanical micromachining and they are exposed to harsh conditions which reduces tool life and adversely affect the economics of the process. The challenge is therefore to maintain the tool rigidity and cutting edge sharpness for extended period of time. Thus, the design, fabrication and durability of micro cutting tools are of significant importance for successful micromachining operations. This review paper aims to provide a comprehensive understanding about the capabilities, characteristics, and limitations of different fabrication techniques used in the manufacturing of micro cutting tools. State-of-the-art micro cutting tool design and coating technology has been presented for various micromachining applications. Possible future research direction and development in the field of micro tool design and fabrication has also been discussed.
Open Access
Novel nanocomposite coatings of nanoparticles
(2011) Toru, Refik Sina
Incorporating nanoparticles into nanocomposite thin-films enables coatings with multi-functionality depending on the particle type and size, and the film morphology. These multiple functions may include, for example, combinations of photocatalysis, hydrophobicity, scratch resistance, and antibacterial property. Here we proposed and demonstrated a new encapsulation nanocomposite with controllable refractive index and potentially additional functional properties for coating photonic devices, for instance, light-emitting diodes (LEDs). To design and implement this nanocomposite coating with tunable refractive index, we employed TiO2 nanoparticles of various diameters because of their relatively high refractive index. We embedded these nanoparticles in our encapsulation sol-gel material during synthesis. In addition, we incorporated several polymerforming chemicals during synthesis to control additional functions such as hydrophobicity and scratch resistance. We used characterization tools of atomic force microscopy, refractometry, contact angle measurement, and scanning electron microscopy to study material properties.
Open Access
Preparation and properties of electrodeposited Ni-B-V2O5 composite coatings
(Elsevier, 2021-01-17) Waware, U. S.; Nazir, Roshan; Prasad, A.; Hamouda, A. M. S.; Pradhan, A. K.; Alshehri, M.; Syed, R.; Malik, A.; Alqahtan, M. S.
Coatings of Ni-B have gained significant importance in various industries owing to their major role in improving mechanical properties including hardness, conductivity, and wear resistance. Despite all these characteristic features, there is still the need for a lot of modifications. This is to improve the properties of the coating so as to increase their durability and overall performance. The current study is based on development of Ni-B-V2O5 composite coating on mild steel substrate through the electrodeposition technique and the investigation of mechanical and anti-corrosive properties of the formed coating. The incorporation of V2O5 particles into the composite coating was confirmed by energy dispersive spectroscopy. X-ray diffraction pattern showed amorphous nature of electrodeposited Ni-B matrix, while the crystalline nature improved with the addition of V2O5 particles to the composite. Field emission scanning electron microscopy and atomic force microscopic studies clearly indicated that the addition of V2O5 particles to the Ni-B coating increased the surface roughness. Further studies reveal increase in the micro-hardness (by 171.11%), and elastic modulus (by 9.4%) in case of the Ni-B-V2O5 composite coating relative to the Ni-B coating. The enhanced micro-hardness was attributed to the inclusion of hard V2O5 particles into the Ni-B matrix, which in turn, may inhibit the dislocation motion in the composite. An increase in corrosion resistance (by 229%) was also experienced in the electrodeposited Ni-B-V2O5 composite coating in comparison to the bare Ni-B matrix, which may be due to the masking of inert V2O5 particles on the active region of the Ni-B composite.