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Properties Of Zn-Bi Composite Coatings Prepared By Ionic Co-Discharge Deposition
Properties Of Zn-Bi Composite Coatings Prepared By Ionic Co-Discharge Deposition
Faculty of Engineering University of Malaya
Zn-Bi composite was synthesized by ionic co-discharge deposition and its properties were investigated. The results show that the Zn-Bi composite with the incorporation of Bi has a finer grain size than the pure Zn coating and improves the mechanical properties. The microhardness is increased by approximately two times simply by adding a small amount of Bi electrolyte into a Zn bath solution. A lower volume loss of the Zn-Bi composite coating compared with the pure Zn coating also indicates that the Zn-Bi coating has a better wear resistance. Link to Full-Text Articles : http://www.sciencedirect.com/science/article/pii/S1003632615635968
Electrodeposition Of Lead-Free Solder Alloys
Electrodeposition Of Lead-Free Solder Alloys
A.S. Md Abdul Haseeb
Purpose - The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)-free solder alloys, so that new studies can be carried out to solve processing issues. Design/methodology/approach - The paper reviews the available reports on the electrodeposition of tin (Sn)-based solder systems and identifies the challenges in this area. Findings - Compositional control remains a major challenge in this area, where the achievement of desired composition for binary and ternary alloys is subjected to uncertainties. The use of chelating agents in the bath and optimization of parameters can assist the achievement of near-desired …
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
Failure Analysis Of Superheater Tube Supports Of The Primary Reformer In A Fertilizer Factory
A.S. Md Abdul Haseeb
Eutectic Sn-Bi alloy is gaining considerable attention in the electronic packaging industry because of its favorable properties such as low melting temperature, good wettability, and good mechanical properties. Miniaturization of electronic devices requires small solder bumps, a few tens of micrometers in diameter. Electrodeposition is a reliable technique for the deposition of small volume of solder. This work focuses on the formation of eutectic Sn-Bi solder by reflowing a metal stack containing sequentially electrodeposited Sn and Bi layers. The effects of layering sequence on the composition and microstructure of the resulting alloy is investigated. Irrespective of the layering sequence, a …
Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films
A.S. Md Abdul Haseeb
Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …
Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films
A.S. Md Abdul Haseeb
Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …
Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films
Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films
A.S. Md Abdul Haseeb
Electrodeposited nanocrystalline nickel-tungsten alloys are being investigated as an attractive alternative to electrodeposited nickel for applications involving fabrication of micro electro mechanical systems (MEMS). Ni-W alloys are also being considered as an environmentally friendly alternative to hard chrome plating in some cases. In applications involving sliding contacts such as in micro-gears in MEMS, mould inserts, etc., tribological properties of Ni-W alloys would be of relevance. In this work, the sliding friction and wear characteristics of Ni-W alloys with different tungsten contents were investigated and compared with that of nickel film deposited from sulphamate bath commonly used in microfabrication. For wear …
Fretting Wear Of Metallic Multilayer Films
Fretting Wear Of Metallic Multilayer Films
A.S. Md Abdul Haseeb
Fretting wear behaviour of electrodeposited Cu/Ni multilayer films with 10 and 5 nm thick sublayers has been investigated against a hardened steel ball as the counter body and compared with that of the constituents, Cu and Ni. The wear tests were carried out by using a ball-on-flat geometry at a translation frequency of 8 Hz and slip amplitude of 100 μm. Friction force was recorded on line during the tests. At the end of the tests, the wear scars were examined by laser surface profilometry, scanning electron microscopy and energy dispersive X-ray microanalysis. It has been observed that the frictional …
Mössbauer Investigation On Electrodeposited Fe-C And Fe-Ni-C Alloys
Mössbauer Investigation On Electrodeposited Fe-C And Fe-Ni-C Alloys
A.S. Md Abdul Haseeb
Hard Fe-C based alloys, Fe-0.96 mass% C and Fe-15.4 mass% C having a microhardness of 810 and 750 HV, respectively, are electrodeposited from sulfate-based baths at 50°C. The Mössbauer spectra consist of high intensity sextet due to ferromagnetic Fe. The linewidth of the sextet is larger for alloys than for the pure Fe, indicating an increased effective field at different Fe sites in the alloys. Absence of any low intensity sextet, which is attributable to the Fe atoms close to the C atoms at the octahedral c-axis position, suggests that the electrodeposited alloys are in an advanced state of aging. …
Thermal Decomposition Study Of Electrodeposited Fe-C And Fe-Ni-C Alloys By Differential Scanning Calorimetry
A.S. Md Abdul Haseeb
Fe-0.96mass%C and Fe-15.4mass%Ni-0.70mass%C alloys with hardness of 810 and 750 HV respectively have been electrodeposited at 50°C from sulphate based baths containing a small amount of citric acid and L-ascorbic acid. Differential scanning calorimetry of the electrodeposited samples has been carried out in the temperature range of 293-725 K in argon atmosphere. Electrodeposited pure Fe is also investigated for comparison purposes. The DSC curves of both alloys contain two exothermic peaks: at about 411 K and 646 K for the Fe-C alloy, and 388 K and 639 K for the Fe-Ni-C alloy. These peaks are irreversible and do not appear …
Xrd, Xps And Sims Investigations On Electrodeposited Nickel-Phosphorous Alloy Coatings
Xrd, Xps And Sims Investigations On Electrodeposited Nickel-Phosphorous Alloy Coatings
A.S. Md Abdul Haseeb
Structural and chemical investigations on electrodeposited nickel-phosphorous alloy coatings by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) are described. Electrodeposition of nickel-phosphorous coatings has been carried out galvanostatically in a hypophosphite bath at two different current densities, namely 20 and 80 mA cm -2. XRD has shown a broad peak indicating an amorphous structure in both cases. XPS shows the presence of Ni 2P compound. XPS also reveals the amount of phosphorous in both coatings to be around 10.20 wt.%. SIMS has shown that the coating deposited at lower current density (20 mA cm …