High pressure cold spray (hpcs) process as coating treatment for magnesium chassis: an overview

Magnesium, Mg and its alloys have excellent physical and mechanical properties for a number of applications. Mg approximately 35% lighter than aluminum and has exceptional stiffness and damping capacity. Disadvantage of this metal and its alloys are highly susceptible to corrosion, particularly in salt-spray conditions and very susceptible to surface damage due to impact. This paper is an outcome of project to address corrosion problem at Mg chasis part in walkie talkie radio using cold spray technique. Current practise of corrosion treatment for Mg chassis structure is using organic coating contains no heavy metals, fluorides with no effect on the alloy composition upon recycling. Disadvantage of this technique is galvanic corrosion at Mg chassis part after 48hrs of salt spray testing and dull finishing. There is keen interest to explore potential applications of high pressure cold spray (HPCS) process onto Mg structure for corrosion treatment. One of the characteristic of cold spray process is creates a negligible heat-affected zone in the as-deposited material and substrate, therefore generating layers that exhibit excellent fatigue characteristics and spray efficiency in HPCS reaching up to 90%. Due to this features, cold spray is potential solution for corrosion treatment to be applied on Mg chassis structur

Preliminary Feasibility Studies of Vegetable Oil as Substitution to Mineral Lubricant / Muhammad Aizat MD Alias and Muhamad Azwar Azhari

The negative factor of mineral oil such as non-biodegradable and toxic influence many researcher to discover the new alternatives lubricant in order to substitute the mineral oils. However, there is restriction when using vegetable oil as lubricant which is there have low oxidation stability which can leads to low lubricity performance. This paper studies the physical and chemical properties in terms of coefficient of friction, wear scar diameter and flash point of vegetable oils and mineral oils. It is expected that the vegetable oils have a higher value of a flash point than mineral oils and lower lubricity performance than mineral oils due to the presence of additive in mineral oils

INFLUENCE OF CALCIUM HYDROXIDE CONCENTRATION ON THE SYNTHESIS NANOSIZED PRECIPITATED CALCIUM CARBONATE

The precipitated of calcium carbonate has attracted much attention because of its numerous applications in various areas of plastics, textiles, rubbers, adhesives, paints and waste water treatment. Nanosized of precipitated calcium carbonate, (PCC) will enhance the properties and give better performance. Its high purity and close controlled particle size and shape are making it the white filler of choice. Nanosized precipitated calcium carbonate particles were prepared using spraying method. The particles were prepared using three (3) different concentrations of Calcium Hydroxide, Ca(OH)2, three (3) CO2 flow rate and three (3) different calcinations temperatures. The three (3) concentration of Calcium Hydroxide that been used are 25g / 200ml, 25g / 400ml and 25g / 800ml and each of these initial solution sprayed at three (3) different CO2 flow rate, 5l / per-minute, 7l / per-minute and 10l / per-minute. Calcium Carbonate, CaCO3 powders were then calcined at three (3) different temperature, 1100°C, 1200°C and 1300°C. Images from FESEM showed morphology of the particles changed to spindle-like or prismatic when the ionic strength of the Calcium Hydroxide, Ca(OH)2 was increased

Oxidation Stability Comparison between Zinc Dialkyldithiophosphate and Zinc Diamyldithiocarbarmate Induced Palm Oil Bio-lubricants / Muhamad Azwar Azhari ...[et al.]

The environmental impact imposed by mineral based lubricant and the threat of petroleum depletion has triggered this study to search for an alternative lubricant using commercialized palm oil. The low oxidation stability of vegetable oil limits the performance of palm oil as a lubricant. This study introduces Zinc Dialkyldithiophosphate (ZDDP) and Zinc Diamlydithiocarbamate (ZDDC) into commercialized palm oil at different concentrations to investigate the effect of oxidation stability using a Rotating Pressure Vessel Oxidation Test. This study discovered that ZDDP displayed a better performance compared to ZDDC in terms of oxidation stability where it exhibited a longer oxidation time of 128 minutes at a concentration of 2 wt%. It can be concluded that the addition of organo zinc compound had improved the oxidation stability of commercialized palm oil as lubricant

Influence of Molybdenum Disulphide (MoS2) Nanoparticles Loading in Treated Used Palm Oil Bio-lubricant on Surface Roughness during Turning of AISI420

The environmental impact and non-biodegradability of petroleum-based lubricants has caused some researchers to shift the formulation of lubricant formulation using plant-based oil, However, food security has caused concerns in development of new bio-lubricants. In this study, treated used cooking palm oil added with Zinc Dialkyldithiophosphate and Molybdenum Disulphide nanoparticles were used as lubricant to assist the cutting of hardened martensitic stainless steel AISI420 using coated carbide tool. Surface roughness of the cut workpiece was investigated using a surface roughness tester. From the study, treated used cooking oil added with ZDDP and 0.8wt% MoS2 nanoparticles displayed the lowest average surface roughness of workpiece with Ra = 0.532µm and total roughness Rz = 4.006µm. This concluded that the new formulated bio-lubricant can successfully replace the readily available commercial cutting fluid as it produces a low surface roughness during cutting process

Feasibility Studies of Treated Used Cooking Palm Oil as Precursor for Bio-Lubricant

The non-renewability and and non-biodegradability of petroleum based lubricants as well as the environmental impacts their waste contributes to the environment has caused the search for a substitute for precursor of lubricant formulation. The food security issue has caused major concerns on how vegetable oil could replace petroleum based product lubricants. This paper reports the feasibility studies of kinematic viscosity, friction and wear properties of treated used cooking palm oil as precursor for development of new bio-lubricant. The treated used cooking palm oil displayed a comparable value of kinematic viscosity of 43.6cSt, coefficient of friction of 0.126 and 122µm which is almost similar to the value of fresh cooking palm oil. Treated used cooking palm oil is seen to be a suitable candidate for precursor of bio-lubricant formulation, However, some additives may need to be added as to increase the tribological properties for treated used cooking oil to be used as a bio-lubricant

Characterization of a Magnetorheological Fluid Damper Applied to Semi-Active Engine Mounting System / M. Hafiz Harun...[et al.]

This study is to propose a hysteresis damper model that can be integrated with the vehicle control system. A prototype of magnetorheological for engine mounting has been designed and tested to realize the objective of this study. The experimental on the prototype of the magnetorheological damper for engine mounts has been conducted in order to investigate the hysteresis of this damper. From the experiment, the results are evaluated in terms of damping force versus piston displacement and also the damping force versus piston velocity. It is significantly shows that the proposed model satisfy the non-linear hysteresis behavior of the MR damper in the form of force-velocity and force-displacement characteristics