Shamsul Baharin Jamaludin

Comparative Study on Thermal, Compressive, and Wear Properties of Palm Slag Brake Pad Composite with other Fillers

The attractive performance-to-cost ratio associated with the incorporation of waste material in composite formulations used to produce brake pads has stimulated the idea of exploring the possible incorporation of additional waste materials in such formulations. Thus, the viability of adding palm slag to the composite formulation used in brake pads was investigated, and the results are reported in this paper. In addition, other fillers, such as calcium carbonate and dolomite, were used for comparative purposes. The properties examined included thermal properties, compressive strength, and wear behavior. The results showed that palm slag has significant potential for use as an alternative to the existing fillers in the composite formulations used to produce brake pads.

Mechanical Properties and Morphology of Palm Slag, Calcium Carbonate and Dolomite Filler in Brake Pad Composites

The development of asbestos free brake pad composites using different fillers was investigated with a intention to substitute asbestos which is known hazardous and carcinogenic. Mechanical and morphology studies were made to clarify the mechanism for compressive strength, hardness and wear rate behavior of different filler of brake pad which were prepared by compression molding of mixture of filler (palm slag, calcium carbonate and dolomite) with phenolic as binder, metal fiber as reinforcement, graphite as lubricant and alumina as abrasive. The result showed that palm slag has significant potential to use as filler material in brake pad composite. The wear rate of palm slag composite was comparable with the conventional asbestos based brake pad. The result also supported by SEM micrograph.

Development and properties of coconut fiber reinforced composite cement with the addition of fly ash

In this paper, the effectiveness utilization of agricultural wastes and industrial wastes in the composite cement has been studied in terms of physical and mechanical properties. Twenty weight percent of fly ash and 80 wt.% of sand were added in the composite cement. Different weight percentages of coconut fiber (3, 6, 9, 12, and 15 wt.%) were added in the composition as reinforcement for cement composites. Water to cement ratio ranging from 0.55 to 0.70 was added into the cement composites accordingly to maintain their workability. Then, the cement composites were cured in water for 7, 14, and 28 days. Results for physical properties (density, moisture content, and water absorption) and mechanical properties (compressive strength and modulus of rupture) are presented.

Structural & Magnetic Characterizations of NiLiZn Nanoferrites Synthesized by Co-precipitation Method

Synthesis of Ni0.5LixZn(0.5−x)Fe2O4 nanoparticles with x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 were realized via co-precipitation method. X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) measurements were performed on the samples to determine the characteristics of the crystal structures and the magnetic properties of the samples, respectively. The spinel phase structures of the samples were confirmed by XRD analysis. Patterns of decreased lattice parameter and increased crystallite size values were observed by increasing the Li concentration at longer synthesis reaction periods. Similarly, for the magnetic properties, both the saturation magnetization (Ms) and coercivity (Hc) were found to vary with increasing patterns at higher Li doping levels and longer synthesis reaction periods. The results and mechanisms concerned were discussed.

Heating Rate Effects on Properties of Powder Metallurgy Fe-Cr-Al2O3 Composites

The aim of this study is to determine the optimum heating rate in fabricating Fe-Cr-Al2O3 composites by powder metallurgy methods. The Fe-based composites reinforced with ceramics are widely used due to their high strength, hardness and wear resistance. Among steps in powder metallurgy methods are mixing, compaction and sintering. Sintering is a very important step due to its ability to evolve microstructural features that govern the end properties. Sintering of green compacts made of iron powder mixture must be performed in vacuum or in a reducing atmosphere because water-atomised iron powder particles are oxidized on the surface and in this way some deoxidation reaction can occur during sintering. The heating process up to sintering temperature, plays a major role, the major proportion of densification occurs during the heating process. The composites produced were subjected to the following tests: densification, Vickers micro hardness, microstructure using SEM and X-ray diffraction analysis. From this investigation, to achieve higher densification and hardness the optimal heating rate is 10°C/minute. X-Ray Diffraction study showed that the fabrication of the composites does not lead to any compositional changes of the matrix phase and the reinforcing phase.

Effect of Beta Tricalcium Phosphate (β-TCP) on Properties of Mg-Zn Composites

In this work, Mg and Zn powder were used to prepare the Mg-Zn/β-TCP composites with different β-TCP composition by using powder metallurgy technique. The composite were mixed using ball mill and compacted at 500 MPa. The composites sintered at 450 °C in tube furnace for two hours. The effects of properties on Mg-Zn with different composition of β-TCP were studied. The results on the effect of β-TCP composition were analyzed in terms of density and microstructural analysis.

Influence of binder in iron matrix composites

The ability to use iron and its alloys as the matrix material in composite systems is of great importance because it is the most widely used metallic material with a variety of commercially available steel grades [1]. The aim of this study is to investigate the influence of binder in particulate iron based metal matrix composites. There are four types of binder that were used in this study; Stearic Acid, Gummi Arabisch, Polyvinyl alcohol 15000 MW and Polyvinyl alcohol 22000 MW. Six different weight percentage of each binder was prepared to produce the composite materials using powder metallurgy (P/M) route; consists of dry mixing, uniaxially compacting at 750 MPa and vacuum sintering at 1100° C for two hours. Their characterization included a study of density, porosity, hardness and microstructure. Results indicate that MMC was affected by the binder and stearic acid as a binder produced better properties of the composite.

Mg-Zn based composites reinforced with bioactive glass (45S5) fabricated via powder metallurgy

Metallic implants are shifting from bio-inert to bioactive and biodegradable materials. These changes are made in order to improve the stress shielding effect and bio-compatibility and also avoid the second surgery procedure. Second surgery procedure is required if the patient experienced infection and implant loosening. An implant is predicted to be well for 15 to 20 years inside patient body. Currently, magnesium alloys are found to be the new biomaterials because of their properties close to the human bones and also able to degrade in the human body. In this work, magnesium-zinc based composites reinforced with different content (5, 15, 20 wt. %) of bioactive glass (45S5) were fabricated through powder metallurgy technique. The composites were sintered at 450˚C. Density and porosity of the composites were determined using the gas pycnometer. Microstructure of the composites was observed using an optical microscope. In-vitro bioactivity behavior was evaluated in the simulated body fluid (SBF) for 7 days...

The Effect of Sintering Temperature to the Microstructure of PM F75 (Co-Cr-Mo) Alloy

PM Co-Cr-Mo (F75) alloys are widely used in implants due to their mechanical properties, good wear resistance and as well as biocompatibility. Currently, they are fabricated by casting technique. In this present research, F75 was fabricated by powder metallurgy technique. The powder was mixed with 2 wt. % of stearic acid in order to form green body and compacted at 500 MPa. The effect of sintering temperature was investigated to observe its effect to the microstructure of F75 (Co-Cr-Mo). Samples were sintered for 2 hours at 2 different temperatures (1250°C and 1300°C) with 10°C/min in argon atmosphere. Physical properties such as density and porosity were obtained by Archimedes principle. Microstructure was observed by using optical microscope Olympus BX41M. The results indicate that increasing the sintering temperature will influence the density and porosity, thus the microstructure itself.

Microstructure and Compressive Strength of Magnesium-Zinc Alloy Reinforced with Different Percentage of Bio-Glass Content

The objective of this work is to fabricate composite Mg-Zn filled with 45S5 bio-glass (5, 10, and 15 wt. %) via powder metallurgy. The microstructure of the sintered composite was investigated using optical microscope and scanning electron microscope. The densities of the composites were also evaluated. The densities of the compacts are increasing with increasing bio-glass content. Compression test was done by the Instron machine. The result showed that bio-glass was dispersed in the Mg-Zn matrix. Compressive strength was decreased as the amount of bio-glass increased. However, the results are still comparable to natural bone, which is important to reduce the stress shielding effect.