Electroplating Jig Design for Mild Steel Nut for Cobalt Alloy Plating

This partly ongoing research focuses on designing a stainless-steel jig holder for varied sizes of mild steel nuts for cobalt alloy plating, scaled to industry-level requirements for field testing. The chosen type of electroplating jig is rack plating. The modelling and analysis of the design were done using SolidWorks software, which included 3D design and finite element analysis. The result shows the strength of the jig holder is reliable for nut sizes ranging from M8 to M16. In conclusion, the jig holder performance has been successfully optimized based on the material and design chosen for its simulation. Keywords: Cobalt-Alloy Plating; Electroplating; Modelling; Finite Element Analysis eISSN: 2398-4287© 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DO

The Effect of Adding Carbon and Vanadium Carbide on Microstructure and Mechanical Properties of Ultra-Fine WC-Co Composite / Salina Budin...[et al.]

Tungsten carbide cobalt (WC-Co) composite is commonly fabricated using powder metallurgy route such as mixing, compaction and sintering process. During the sintering process, densification of the powders takes place where WC grains having higher solubility would dissolve in the Co-rich liquid. One of the crucial aspects during sintering process is grain growth. The inappropriate sintering state will lead to an abnormal grain growth, which consequently will deteriorate the mechanical properties of WC-Co composites. Thus, a suitable grain growth inhibitor is recommended to be added in WC-Co composites to minimize the problem. In the present work, the effect of adding carbon (C) and vanadium carbide (VC) on the mechanical properties of ultra-fine WC-Co composite is investigated. The amount of Co and C is fixed at 6wt% and 0.2wt%, respectively, while the amount of VC is varied in the range of 0 to 1wt%. It is observed that, an addition of C and VC in the WC-Co composite is able to control the abnormal of grain’s growth. The relative density decreases with the increasing of wt% of VC. Similar trend is observed for hardness and transverse rupture strength (TRS). An increasing of the wt% of VC will cause excessive VC particles sited in the WC/Co grains boundary, thus hinder the liquid Co wettability to fill in the porosity between WC particles. The present of porosity will consequently permit grains growth activities. The finest grains size is achieved at the formulation 2 with 0.2wt% C and 0.4 wt% VC. The maximum hardness and TRS is attained at a similar formulation. The hardness of WC-Co composite with 0.2wt% of C and 0.4wt% of VC was approximately 40% much higher than commercial cutting insert

Physicochemical Characteristics of Magnesium Hydroxyapatite (MgHA) Derived via Wet Precipitation Method / C. M. Mardziah ... [et al.]

Hydroxyapatite (HA) has been known for so many decades as an implant material for medical applications due to its chemical composition that is very similar to the inorganic component of human bone. However, synthetic HA possesses relatively low mechanical strength characteristic, making it less suitable to be used in load bearing applications. Thus, the presence of metal ion like magnesium (Mg) is expected to improve the properties of synthetic HA as biomedical devices. The main objective of this research is to develop and characterize the magnesium hydroxyapatite (MgHA) nanopowders derived from the wet precipitation method. The amount of Mg, which acts as a metallic dopant in HA were varied at 0, 5 and 10% and calcined at 700C for imperative comparison. The resultant nanopowders were then characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) to examine their physicochemical properties. Morphological evaluation by FESEM showed that the particle size of 10% MgHA powders was larger and spherical in shape but still highly agglomerated at calcination temperature of 700C. This result coincides with the data obtained from the XRD analysis, which revealed that the particle size of pure HA, 5 and 10% MgHA after calcination was 87 nm, 98 nm and 116 nm, respectively. These results demonstrate that doping Mg into HA has caused an increase in the particle size, proving that Mg acts as a sintering additive during the calcination process

Corrosion Behavior of Heat Treated Nanocrystalline Co Ni Fe Coating on Stainless Steel / Koay Mei Hyie...[et al.]

Corrosion is an essential environmental phenomenon in industry that can deteriorate the performance of steel and shorten the lifetime of steel. The failure due to corrosion can cause leakage, fracture, contamination of corroded elements to the product or equipment having the corroded steel parts. To overcome the corrosion problem, nanocrystalline coating has been proposed to improve the corrosion resistance of steel. In this investigation, nanocrystalline Co-Ni-Fe was used to protect the stainless steel from sodium chloride environment. Co-Ni-Fe has been identified as a potential candidate in corrosion resistant coating. This material is recognized as a green material because it is not toxic and hazardous to environment. In this study, nanocrystalline Co-Ni-Fe having less than 30 nm crystallite size was developed by low cost electrodeposition method. The coating electrodeposition was carried out at pH 1 and current density of 0.143 A/cm2. The synthesized Co-Ni-Fe coated stainless steel was heat treated at 700C in different types of gas conditions. This paper focused on comparison between the samples with and without heat treatment. Although there is no phase changed during the heat treatment as proven in XRD analysis, nanocrystalline Co-Ni-Fe heated using mixed gases showed the tendency to form the dendritic structure. In the presence of hydrogen and argon mixing gases in heating atmosphere, the sample revealed higher oxygen content of 5.34 wt% and exhibited the highest corrosion rate in sodium solution. Anyway, the coating still protected the stainless steel from corrosion after exposed to 24 hours in salt fog test as compared to the pure stainless steel which was corroded at the same test. In conclusion, the heat treatment applied on the coating sample is believed to produce dense coating and thus enhance the corrosion resistance of the coated steel

Physicochemical characteristics of magnesium hydroxyapatite (MgHA) derived via wet precipitation method

Hydroxyapatite (HA) has been known for so many decades as an implant material for medical applications due to its chemical composition that is very similar to the inorganic component of human bone. However, synthetic HA possesses relatively low mechanical strength characteristic, making it less suitable to be used in load bearing applications. Thus, the presence of metal ion like magnesium (Mg) is expected to improve the properties of synthetic HA as biomedical devices. The main objective of this research is to develop and characterize the magnesium hydroxyapatite (MgHA) nanopowders derived from the wet precipitation method. The amount of Mg, which acts as a metallic dopant in HA were varied at 0, 5 and 10% and calcined at 700C for imperative comparison. The resultant nanopowders were then characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) to examine their physicochemical properties. Morphological evaluation by FESEM showed that the particle size of 10% MgHA powders was larger and spherical in shape but still highly agglomerated at calcination temperature of 700C. This result coincides with the data obtained from the XRD analysis, which revealed that the particle size of pure HA, 5 and 10% MgHA after calcination was 87 nm, 98 nm and 116 nm, respectively. These results demonstrate that doping Mg into HA has caused an increase in the particle size, proving that Mg acts as a sintering additive during the calcination process

Conversion of strontium hydroxyapatite nanopowders to porous scaffolds for bone implant application

The fabrication of strontium hydroxyapatite (SrHA) porous scaffolds was accomplished by using polymeric sponge method. To prepare the porous samples, the synthesized SrHA nanopowders were mixed with distilled water and appropriate amount of dispersing agent followed by drying in the ambient air and sintering at 1300°C. The compressive strength of the materials was strongly influenced by the porosity, while there was almost no dependence on the crystallinity of the powders since XRD patterns showed high crystallinity of HA phase for all porous samples. Morphological evaluation by FESEM revealed that the SrHA scaffolds were characterized by macro-micro interconnected porosity, which replicates the morphology of the cancellous bone. Compression test on the porous scaffolds demonstrated that doping 10 mol% of strontium in HA has increased the compressive strength by a factor of two compared to the undoped HA with 1.81±0.26 MPa at 41% porosity

Corrosion Study of Electrodeposited Co-Ni-Fe Protective Coating on Electroless Nickel Immersion Gold (ENIG) Flexible Printed Circuit

AbstractFlexible Printed Circuits (FPCs) have been vastly used in electronic devices such as mobile phones and sensors. This multi-layer polymer is used in electronic packaging to interconnect high performance devices. Electroless Nickel Immersion Gold (ENIG) is the final finishing method commonly applied on FPCs due to its excellent planarity, wear or abrasion resistance and electrical contact performance. However, corrosion problem on FPCs surface may influence the electrical conductivity, performance and thus affect the functionality of the end product. Previous published literature showed that Co-Ni-Fe enhanced the corrosion behavior of metals. Therefore, ternary Cobalt alloys (Co-Ni-Fe) have been synthesized as the protective coating on ENIG FPCs in this research. A low cost electrodeposition method is applied to produce a Co-Ni-Fe protective coating to improve the corrosion resistance of ENIG FPCs. The result will be compared between FPCs with and without protective coating. Co-Ni-Fe solution for electrodeposition process was prepared at pH 1. The current applied to coat the FPCs is 0.6 ± 0.05 A. The experiment conducted at 50°C ± 0.5 and performed at 30s and 60s of deposition time. Irregular shape of microstructure with grain size range from 46nm to 88nm was observed under FESEM micrographs. Corrosion test was performed by using Potentiodynamic Polarization technique under acidic environment. The corrosion rate per year of the FPCs after coated with electrodeposited Co-Ni-Fe showed lower corrosion rate than ENIG FPC. The corrosion behavior and surface morphology studies have shown that the electrodeposited Co-Ni-Fe coating improved the corrosion rate of ENIG FPCs