Zuraidawani Che Daud

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...

A Short Review on In Vitro Bioactivity Behavior of Magnesium Composites

Research and development on the biomaterials are increasing due to the demand for materials that can bond to the living bones and by any chance can avoid second surgery procedure. Good bonding between bones and biomaterials or artificial implant can avoid loosening that due to the friction and wear. Currently, magnesium alloys are being actively researched because of their ability to serve as structural support in short term and can be absorbed in the body after healing process is completed. The addition of bioactive components such as hydroxyapatite and bioglass into magnesium is made to improve the bioactivity behavior of magnesium alloys. This paper summarizes the past and current studies of magnesium alloys in regards of in vitro bioactivity behavior, biomineralization and apatite formation mechanism.

Corrosion behavior of Mg-3Zn/bioglass (45S5) composite in simulated body fluid (SBF) and phosphate buffered saline (PBS) solution

Magnesium has emerged as promising materials in biomaterials research due to its good mechanical and physical properties closer to human bones. However, magnesium has poor corrosion resistance to chloride ions that exist in human blood plasma thus preventing its application in biomedical. The addition of zinc and bioglass can reduce magnesium corrosion rate. In this work, the effect of different solution media (Simulated Body Fluid and Phosphate Buffered Saline) to the corrosion behavior of Mg-Zn/bioglass (45S5) composites was investigated. The composites of Mg-3Zn added with 5, 10, 15, 20, 15 and 30 wt. % bioglass were fabricated by powder metallurgy. The composites were prepared by mixing at 140 rpm for 1 hour, pressing at 500 MPa and sintering in an argon environment at a temperature of 450°C for 3 hours. Sintered samples were immersed in Simulated Body Fluid (SBF) and Phosphate Buffered Saline (PBS) in order to investigate the corrosion behavior. Samples mass loss was determined after 3 days of immers...

Biomedical Applications: Composite Metal Alloys with Additives

Recently, many researchers focused on biocompability, corrosion resistance and properties behavior of implant materials in order to length the endoprostheses life. One of the rapid development areas of research is in the biomaterials field. Historically the uses of biomaterials has been to replace diseased or damaged tissues. This present paper reviews the research works carried out in the field of composite metal alloys reinforced with additive and to analyze the influence of modifying additive on mechanical properties of composite materials on the cobalt (Co), titanium (Ti) and magnesium (Mg) based alloy. The desirable mechanical properties of the matrix component compensate for the poor mechanical behavior of the biomaterials, while in turn the desirable bioactive properties of the additives improve those of metal alloys. The following additives were reviewed for research: poly methyl methacrylate (PMMA), fluoroapatite (FA) and bioglass. Results show that these composites can be the alternative materials for biomedical applications.

The Effect of Sintering Temperature on the Sintered Mg/3wt.%Zn-Bioglass (45S5) Composites

Magnesium and bioglass are a good combination to create biocompatible and bioactive materials. Magnesium-bioglass composites can be manufactured by casting or sintering. This work was aimed to manufacture the composite Mg-3wt.%Zn filled with 5, 10, 15, 20, 25 and 30wt.% bioglass (45S5) by powder metallurgy. Two sintering temperatures of 450 °C and 550 °C were used to sinter the samples. The sintered samples were characterized using optical micrograph and X-Ray diffraction (XRD). Optical micrograph shows that increasing of bioglass content lead to smaller grain size. XRD analysis shows no new crystalline compound detected on XRD pattern for Mg-3wt%Zn sintered at 450 °C ad 550 °C.

Effect of Aging Temperature to the Corrosion Behaviour of 5D86 Aluminum Alloy

The voltage potential corrosion effect of aged 5xxx series 5D86 Al alloy were investigated using Open Circuit Potential (OCP). The 5D86 Al alloy were heat treated to 600 °C and soaked in 4 hours time and immediate quenched into iced cold water. Then the heat treated samples were aged at five different temperatures for 4 hours and quenched into iced cold water. Temperatures used to aged 5D86 Al alloy is 150 °C, 250 °C, 350 °C, 450 °C and 550 °C. The phases of AlxMgy were investigated using XRD. The hardness of these materials was investigated and studied using Vickers microhardness. The corrosion behavior of 5D86 Al alloys was investigated using Open Circuit Potential (OCP) testing. Solution used for OCP testing is 3.5% NaCl for 120 min with 10 mm2 surface area. The voltage potential of 5D86 Al alloys aged at 250 °C was nearing positive value which means the corrosion rate of aged sample at 250 °C have the higher rate corrosion resistance.

The Effect of Microwave Sintering Time to PM Aluminum Alloys

Microwave sintering is new sintering technology method to produce Al alloys. The advantages of this method because of very short sintering time and less production cost compare to conventional sintering. However, the main problems in microwave sintering are required to be controlled sintering time due to rapid sintering mechanism. Therefore the effect of microwave sintering time to PM Aluminium will be studied. The compacted and sintered aluminium powder is placed in a microwave oven at a different period of 5 minutes, 10 minutes, 15 minutes and 20 minutes. Compression of 150 MPa is applied on aluminium powder to form pellets. Palette is shaped to 1cm in diameter and weighs 1g. SiC is placed together with aluminium samples in the microwave for the purpose of absorbing electromagnetic energy and is converted to heat. Results of different period sintering of aluminium pallet production altered physical properties of each sample. For a rapid sintering time, aluminium pallet does not show any binding reaction between powder particles. Whereas, for long microwave sintering period, solid particles phase change into solid-liquid phase caused by the movement and the formation of bonds between particles. Hence, this will be affecting the mechanical properties of the sample material.

A Study of PM Mg-HAP Composite: Corrosion and Microstructural Evaluation

Mg-HAP Composite produce by powder metallurgy (PM) methods is one new biomaterial usually applied as biomedical implant. However, the sensitive Mg metal to surrounding environment is giving the bad impact for this biomaterial because of the presence hydroxyapatite particle in Mg matrix. The aim of this work is to study the corrosion behavior and microstructural evaluation of composite biomaterial Mg with different percentage of Hyroxyapatite (HAP) (5, 10, 15 and 20 wt. %) produced by powder metallurgy (PM) method. The corrosion test was done using electrochemical methods and the microstructure after corrosion test was observed using optical microscope. Based on the results, the different percentages of HAP were influenced the corrosion rate of the Mg-HAP composite. The percentage of HAP content in Mg were greatly influences the corrosion behavior of the alloy. Sample Mg-20wt% HAP has the lowest corrosion rate which is 0.16mm per year, while sample Mg-15wt% HAP has the highest corrosion rate, 0.37 mm per year.

Fabrication and Characterization of Porous F-75 for Potential Application in Tissue Engineering

Porous F-75 (Co-Cr-Mo) was produced by powder metallurgy technique. F-75 powder was mixed with space holder and compacted using different pressures (300 MPa, 350 MPa, 400 MPa, 450 MPa). The green samples were sintered at 1150 °C in a tube furnace under argon atmosphere. Sintered samples were examined in terms of bulk density, porosity, hardness and pore size. Microstructural analysis was carried out using a scanning electron microscope (SEM). Microstructure analysis showed that pore sizes and pore shape were influenced by different compaction pressure. The hardness of the samples increased as compacting pressure increased. Density and porosity remained constant at certain level.

The Effect of Sintering on the Properties of Powder Metallurgy (PM) F-75 Alloy

F-75 (Co-Cr-Mo) alloy are widely used in the production of medical implants because of their excellent strength properties, hardness and also one of the biocompatible materials that very suitable in human body environment. In this research, the effect of sintering in terms of sintering temperature and sintering time has been studied by focusing on the microstructure, physical and mechanical properties of F-75 alloy. The samples were prepared by blending the starting material at 160 rpm for 30 minutes, uniaxially pressing at 500 MPa and sintering in an argon atmosphere at two sintering temperatures (1300°C and 1350°C) for four sintering times (60, 90, 120 and 150 minutes). The results show that the grains and bulk density increased with the increasing of sintering temperature and sintering times. However, opposite results were obtained for apparent porosity, hardness and compressive strength