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This study presented the ballistic properties and impact strength of the aluminum alloy AA 7075-reinforced nano-SiC composites, which were produced by stir-squeeze casting and forging processes. Ballistic tests revealed that the samples met the National Institute of Justice (NIJ) Type II standard, except for samples that were not forged. The other characteristics examined were microstructural observations analyzed using optical and scanning electron microscopes. As a result of the pinning effect, the microstructure of the samples showed a decrease in grain size as the SiC content increased, except for samples with over 0.25 vf% of nano-SiC. This effect was observed in samples with and without forging. The forging process decreased grain size further, affecting ballistic and mechanical properties. The addition of 0.3 vf% nano-SiC improved the ballistic properties and impact strength, resulting in the highest impact value of 7.7 J, despite higher values of the average ballistic diameter of perforation (about 4.7 mm) and average indentation depth (about 17.22 mm) measured on this sample.

The traditional graphitization process involves the use of non-renewable carbon sources and high temperatures, which are time-consuming and expensive. Biomass has been proposed as an alternative renewable source of carbon, which can be graphitized at lower temperatures using transition metal catalysts. The article highlights successful research on graphitization of various biomass carbon sources, such as coconut coir, whey protein, pine wood sawdust, mangosteen peel, miscanthus grass, and palm kernel shell waste, using metals as a catalyst. The graphitization process using catalysts derived from transition metals has been shown to reduce the graphitization temperature, shorten the graphitization time and improve the physicochemical properties of the resulting graphite material.

Aluminum alloy AA 7075 majorly consists of Zinc and Magnesium, and it has been known as an alloy with high strength and ability to be heat treated. In regard to that, AA 7075 alloy was investigated to determine its application in military vehicles that require high protection and great mobility capabilities. The addition of Al_2O_3 can be done to improve the mechanical properties of the material such as hardness and impact toughness that is related to the protective ability of the material. This research was conducted to determine the effect of adding nano Al2O3 and heat treatment o n the ballistic resistance of composite plates. The composites were fabricated by the squeeze casting method followed by heat treatment of T6 at 470 °C for two hours, water quench, and artificial aging at 120 °C for one hour. The reinforcement of nano Al_2O_3 is added to the melted aluminum alloy when the fabrication process takes place as much as 0.1, 0.2, 0.3 wt%. Furthermore, the composite plate was tested by ballistic testing Type II and III according to NIJ standard. Other characterizations were also car ried out on the samples such as microstructural observations and hardness testing. The results of the characterization have found that all samples have protective ability in Type II ballistic testing but do not have protective ability in Type III ballistic testing. The addition of reinforcing particles affects the value of the hardness of composite material. Heat treatment increases the hardness value, impacts toughness value, and penetration trace in ballistic testing which has a direct relationship to microstructural changes that occur during the heat treatment process.

The objective of this study is to produce b-wollastonite from amorphous SiO2 obtained from bamboo leaf ash (BLA) and CaO derived from meretix meretix shell (MMS) using solid state reaction. Amorphous SiO2 utilization in this work obtained by precipitation of BLA and calcined at 700 °C for 3 h, whereas CaO MMS was generated by calcination of MMS at 1000 °C for 5 h. High purity amorphous SiO2 obtained was 99.325 wt % and CaO purity obtained was 97.531 wt %. Single phase of b-wollastonite found in this study as confirmed by XRD results. The vibrations at 933.42 , 904.49, and 890.99 cm-1 were caused by the Si-O-Ca bond, which shows the bonding of b-wollastonite obtained from the FTIR. The acicular morphology of b-wollastonite with average grains size of 0.28,0.33 and 0.71 mm was obtained for the samples calcined at 900 , 1000 , and 1100 °C respectively.

In this work a simple process for the production of high purity biogenic amorphous SiO2 derived from rice husk ash have been studied. Rice husk ash obtained from heat treatment of rice husk and citric acid leaching of rice husk at 700 o C for 6 h. Improvement of purity SiO2 from rice husk ash conducted by precipitation technique. The precipitated SiO2 particles obtained were characterized by x-ray fluorescence (XRF) analysis, Fourier transform infrared (FTIR) spectroscopy, and x-ray diffraction analysis (XRD). The XRF result shows that the high purity of biogenic amorphous SiO2 obtained is 99.258 %. The XRD result shows the silica have amorphous phase and for the FTIR results shows bending and stretching vibration of Si-O and Si-O-Si.

Wood is the largest source of cellulose in the nature however it has a low strength. In other hand, bacteria cellulose as a pure cellulose has a higher tensile strength than wood. Wood reinforced with bacterial cellulose was produced by self-assembly approach with veneer soak into the fermentation medium. The product of this research is hybrid veneer processed thermos-hydro-mechanical treatment. It has been used to give a change in its mechanical properties. This research analyzed mechanical tensile test, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The result showed that bacteria cellulose had impact to increase tensile strength of veneer and improve the molecular strength between cellulose fibers. Hydrogen bonds were formed between veneer fibers and bacterial cellulose then those bonds stick together and resulted in strong adhesion.

The emerging portable device and electrical vehicle require safe, portable, and high-power energy sources which may be supplied by lithium-ion battery (LIB). The existing carbon anode exhibits several issues in terms of safety such as volume expansion and formation of solid electrolyte interphase (SEI) which can be overcome by applying Li4Ti5O12 (LTO) as an anode. However, the low electronic and ionic conductivity are the main bottlenecks of LTO. This research focuses on synthesizing LTO using TiO2 synthesized through the sol-gel method. Furthermore, the effect of TiO2 crystalline size will be discussed accordingly. The crystalline size of TiO2 was tailored by applying calcination temperature at 300 °C, 400 °C, and 500 °C and was heated for 6 h. The crystallite size shown by XRD patterns was 8.01 nm, 13.82 nm, and 27.01 nm, respectively. The best electrochemical properties were exhibited by LTO 300 showing the initial specific capacity of 164 mAh g−1.

Aluminium Matrix Composites (AMCs) made by A356 as matrix and nanoAl2O3 as reinforced are widely used for high performance application because of light weight and alumina has good performance at high temperature. In this study, the nanoAl2O3 used varied from 0.1 vf-% to 1.2 vf-%, which subsequently determined the optimum point. In addition, the magnesium with 10% are added as a wetting agent between aluminium and nanoAl2O3 as reinforced. Stir casting process is carried out for 2 minutes and 4 minutes for the degassing process using argon gasses then pouring molten metal in to the mold at 800°C. The effect of nanoAl2O3 on the mechanical properties and microstructure of the composites was investigated. The result showed that the tensile strength decreased with the addition of nanoAl2O3 but the hardness increased. Increasing of hardness mainly caused by grain refinement, and particle strengthening which act as obstacles to the motion of dislocations. Addition of nanoAl2O3 as reinforced also tend to form microporosity and agglomeration which would decrease the tensile strength of composites. The optimum strength was reached by 0.5 %Vf nanoAl2O3 with the value of 140 MPa and hardness of 46 BHN which was supported by low porosity level. Keyword : Al A356, Al2O3, nanoComposite, Stir Casting

This study was conducted to investigate the effect of Al2O3 on characteristics of A356 reinforced composites. The addition of Al2O3 as reinforced varied from 2 vf-% to 15 vf-% through Stir Casting methods to obtain the optimum addition Al2O3 as reinforced in mechanical properties of composite A356 as matrix and Al2O3 as reinforcement. Magnesium with of 10 wt-% was added to improve wettability between Al2O3 particles and Al A356. Addition of Magnesium is expected to form the spinel phase MgAl2O4 in interface area between Al2O3 and Al A356.The optimum tensile strength was found at 2 vf- Al2O3 with value 131.55 Mpa. However, the value is still lower than the tensile strength of Al A356 As cast. It is caused due to the porosity and the agglomeration of Al2O3 were found in the microstructure of the composite Al A356/Al2O3. The Hardness increased from material monolithic Al A356 as cast, reached 37.43 HRB.

Li4Ti5O12/Sn was successfully synthesized by a solid-state method using the High Energy Ball Mill Machine as anode for Lithium-Ion batteries. The addition of various (10%, 20%, 30%) Sn-micro particle is aimed to enhance LTO's conductivity and capacity. Characterization of the sample's structure was performed using X-ray diffraction (XRD), which expose the presence of TiO2 rutile and Sn in each sample. The surface area of samples observed using Brunner-Emmet-Teller (BET), which indicates the different surface area of each Sn addition. Scanning electron microscopy (SEM) suggested agglomeration and poor distribution appear in every sample. Cyclic voltammetry (CV) was performed to measure the battery's performance. Two peaks occur as a sign of reversible reaction. The impedance of Li4Ti5O12/Sn measured using electrochemical impedance spectroscopy (EIS), the test performed before and after Cyclic voltammetry (CV), each test showed the different result for each sample. Other than EIS and CV, Charge-Discharge (CD) also performed, examinations in different C-rate were performed, and higher Sn concentration leads to lower stability in high C. The result reveals that the addition of 20% Sn optimizes Li4Ti5O12 in enhancing capacity and conductivity.

Synthesis and characterization of LiMn0.7Fe0.3PO4/CNT/C composite used as lithium ion battery cathode has been carried out. The active materials of LiMn0.7Fe0.3PO4 was synthesized via hydrothermal method from the precursors of LiOH, NH4H2PO4, FeSO4.7H2O and MnSO4.7H2O. The activated carbon was pyrolyzed from coconut shell whereas the carbon nanotube (CNT) was commercially available in the market. The composite was prepared using a ball-mill to mix the components homogeneously. Simultaneous thermal analysis STA was used to determine the formation temperature of LiMn0.7Fe0.3PO4 to which the sintering process was conducted at 700 °C. After sintering, the materials in powder forms were characterized using scanning electron microscope (SEM) to examine the morphology, whereas X-ray diffraction (XRD) was used to identify the phases formed. The performance of the composite as lithium ion battery cathode was characterized using electrochemical impedance spectroscopy (EIS) and battery analyzer. Secondary electron image from SEM showed that the samples have homogeneous particle distribution. Examination result from X-ray diffraction indicated that LiMn0.7Fe0.3PO4 phase has been successfully synthesized with small impurities from a secondary phase. Performance analysis showed that the presence of activated carbon and CNTs in LiMn0.7Fe0.3PO4 to form LiMn0.7Fe0.3PO4/CNTs/C gives significant improvement in the conductivity; however, some more improvement is still needed for the capacity.

Lithium-ion capacitors (LIC) is believed to be an ideal option in certain application as energy storage device due to its properties either possessing high energy density (four times higher than electrical double-layer capacitor) or having as much power density as a supercapacitor. In this study, a biomass-based activated carbon (WHAC) was prepared by using the water hyacinth plant through the activation process utilizing a chemical activating agent, KOH. The water hyacinth was carbonized at 500 °C for a 1 h holding time with a ramping temperature of 10 °C/min. Then, the LICs electrode is constructed by two different types of electrode, WHAC as the main active material of cathode and lithium titanate oxide (LTO) for the anode. The biomass-derived activated carbon exhibits a high specific surface area of 791.8 m2/g and a high pore volume of 1.13 m3/g. The assembled LiCs shows a reasonable electrochemical performance with a maximum specific capacitance of 1.12 F/g with the highest specific energy of 4.48 Wh/kg and specific power of 34.14 W/kg. This LIC cell is one of the promising candidates for future applications due to its low-cost materials and owns more advantages than typical Lithium-ion Batteries (LIBs).

Lithium Titanate (LTO) is one of the anode materials that has good performance because of its unique properties, which is zero-strain. In this study, LTO was synthesized using the sol-gel method and mechanochemical hydrothermal with LiOH as the source of lithium-ion. Silicone oxycarbide (SiOC) is a ceramic material synthesized through a simple pyrolysis process of silicone oil precursors. Carbon used in this study is a carbon activated process so that activated carbon is obtained with a large pore size. The addition of activated carbon to the LTO is done during the sol-gel process, while the addition of SiOC to LTO-C is performed during the slurry making process. SEM-EDS shows the extent of the elements in the sample where Ti, F, Si, O, and C are present. Also, SEM-EDS characterization shows an increase in the amount of carbon in each sample. XRD shows the presence of the LTO spinel phase and impurity phases such as TiO2 rutile and anatase, and Li2TiO3. In EIS performance testing, low resistivity expresses high conductivity. In this research, high conductivity is owned by LTO-1% C/SiOC. In addition, CV and CD performance tests were performed where the highest specific capacity was obtained in the LTO-5%/SiOC samples.

Lithium titanate (Li4Ti5O12 or LTO) is a very promising anode material to replace graphite in li-ion batteries due to its safety and fast-charging ability. However, due to the low theoretical capacity of LTO, a strategy must be developed to overcome this problem. Synthesizing LTO by the combined sol-gel and solid-state method, and the addition of tin powder together with activated carbon, is expected to increase the specific capacity of the anode material. The tin powder compositions in this research were 5wt%, 7.5wt% and 12.5wt%. Further, to investigate the influence of activated carbon, 5wt%, 15wt%, and 25wt% activated carbon were added, while the composition of Sn was kept at 7.5wt%. XRD, SEM and BET surface area measurements was performed to characterize the morphology and structure of the samples. The performance of the battery was analyzed using EIS, CV and CD. The results show that TiO2 rutile was present in the LTO samples, with peak rutile decreasing significantly with the addition of carbon. More disperse particle morphology was obtained by the addition of activated carbon. The LTO/Sn anode material exhibits excellent reversible capacities of 191.1 mAh/g at 12.5wt% tin. Additionally, the LTO/Sn@C has the highest specific-capacity at 270.2 mAh/g, with a composition of 5wt% carbon and 7.5wt% Sn. The results show that LTO/Sn@C is a potential anode material for the future.

Today, due to environmental reasons and limited of fossil resources take many researchers to develop new and renewable materials. Bio-composites which is consisted of synthetic polymers matrix and natural fibres, is one of the alternatives to reducing its problems. Among of natural fibre that has good potential to be used as reinforcement in synthetic polymer matrices is sorghum fibre. However the hydrophilic nature of natural fibers causes it to be incompatible with synthetic polymer matrices which have hydrophobic properties and it’s need to surface modified with particular treatment. The aim of this work was conducted to study the effect of hydrothermal treatment through pressure boiled method by using distilled water in a pressurized stainless steel pan cooking for 5 minutes to defibrillation and hydrophilic properties of stalk sweet sorghum fibres. Evaluation of the experiments was characterized with Field-Emission Scanning Electron microscope (FE-SEM), Fourier Transformation Infra-Red (FTIR) Spectroscopy and sessile drop test instruments, respectively. The experiment was found that using hydrothermal treatments through pressure boiled method led to a removal of binding materials, such as a wax, hemicellulose and lignin, and enhancement the hydrophilic properties of sorghum fibres.

Bacterial cellulose is an interesting material. Besides its biocompatibility bacterial cellulose also has a unique structure and properties. The mechanical properties of cellulose might depend on an amount of hydrogen bond in a material. Due to the water softening effect, a combination of thermal treatment and the hydro-mechanical compression was proposed to remove the water content of bacterial cellulose. The treatment was followed with electric current flow through an electrolyte medium in bacterial cellulose to improve the strength of the hydrogen bond. Mechanical properties improvement of bacterial cellulose treated with the proposed method is discussed.

Lithium Titanate (Li4Ti5O12 or LTO) is one of the best candidates to replace graphite as anode material in the lithium-ion battery (LIB), due to unwanted solid electrolyte interphase (SEI) layer formation that consumes Li+ ion and reduces LIB performance and may cause thermal run-away. The ability of LTO to avoid SEI formation and undergo zero-strain during intercalation makes LTO has excellent safety during application. However, the spinel lithium titanate has the low theoretical capacity and poor electronic conductivity. This less conductivity brings limitation to its application. The sol-gel method and combining the LTO with Si that possesses a high theoretical capacity are the key factor to overcome the LTO disadvantages. To attain its high power, safety factor and low-cost fabrication properties, hydrothermal-mechanochemical treatment were used in sol-gel synthesis method in order to outgrowth (Li4Ti5O12)nanostructure. Then, the 5 %, 10 %, and 15 % weight ratio percentage of silicon nano-particle were added into electrode composite in order to enhance the capacity of lithium titanate anode. All samples were characterized using XRD, SEM and TEM. The active anode material LTO/Si nano was coated and prepared into coin cell battery. The assembled coin half-cell used lithium metal foil as the counter electrode. The battery performance was tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge-discharge (CD). The XRD results showed that the obtained compounds of lithium titanate (Li4Ti5O12) crystalline spinel and the impurities of TiO2 rutile. The SEM micrograph results showed almost uniform morphological structures as agglomerates in most of the samples. While, the TEM image of Si nano had a crystalline phase with the particle size less than 100 mm. However, the presence of unwanted SiOx layer was not clearly observed. Addition of Si-nanoparticle could increase the specific capacity to above the LTO theoretical capacity, however, the formation of SiOx insulating layer is predicted to be the main hindrance that reduces the effectiveness of addition of Si nanoparticle to the present LTO compound. The hydrothermal treatment of the sample could enhance the performance of nano-composite LTO/Si anode. Based on CD results, the obtained LTO/Si compound possesses the discharge capability up to 12 C. The CV and CD results showed the optimum percentage of 10 % wt. Si and best capacity of the sample was obtained at 229.72 mAh/g

Polypropylene (PP) is one of the biggest petro-polymers, which is used in very wide application nowadays. The environment problem due to materials such as plastics having very long time degradability, and critical petroleum sources have promoted some studies to empowerment of natural resources such as natural fibres for substituting or at least modifying petro-polymers. Because of biodegradability obtained from natural source, sorghum fibers are interesting to be used as filler in PP composites, despite of weak compatibility between them. Surface modification on the sorghum fibers through alkalinization prior to acetylation was aimed to improve the fiber compatibility to PP. The treatments were expected to substitute hydroxyl group in the sorghum fibers, into acetic ester group in order to increase their hydrophobicity as the fillers. Moreover, the treatments were able to unbundle single fibers into micro-fibrillated cellulose (MFC) fibres with increase in crystallinity index. Usage of this MFC fiber as filler in PP leads to improvement of the composite performances such as thermal properties. In this study, Fourier Transformation Infra-Red (FTIR) Spectroscopy, X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscope (FE-SEM) were used to evaluate the performances of the Sorghum fibers after the treatments and as the filler in the Sorghum fibers/PP composites. The experimental results showed the MFC fibers as the smallest sizes in 5.0 microns and the highest crystallinity index up to 79.1 %, obtained from alkalinization with 2.5 M NaOH prior to acetylation with 17.4 M CH3COOH and the glacial (CH3CO2)2. Compatibility study of the treated Sorghum fibers on PP shows an improvement indicated by a strong interaction between the fibers and PP on morphology observation, increase in melting point of PP from 163.4°C (using virgin Shorgum fibers) into 163.6°C (using treated Sorghum fibers) in DSC measurements.

Aluminium 6061 composites have been succesfully produced by stirr casting method. The process involved melting aluminium at 800°C and mixed with AlSr, TiB and Mg to produce master alloy of matrix phase, then degassing to remove all of gas entrapped in molten aluminium by argon. There are two types of particles reinforced added into aluminium to produce aluminium composite such as SiC and Al2O3. The particles reinforced addition for both SiC and Al2O3 are started from 2vf-% to 10vf-% to obtain the optimum compostion which have good mechanial propperties. The addition of 10wt-% Mg is to promote wetting between matrix and reinforced while the addition of AlSr and TiB are to improve mechanical properties by modifying the eutectic structure as well as grain refinement of the matrix phases. The two composites are compaired both mechanical properties and microstructure analysis. The mechanical properties of Al/SiC composites such as tensile strength, elongation, and hardness have a maximum value at addition of 10 Vf-% SiC with the value up to 230 MPa, 6.5%, and 62 HRB respectively. While for Al/Al2O3 composites have the highest tensile strength and elongation at 6 Vf-% Al2O3 with the value of 224 MPa and 7% respectively, but the highest hardness is obtained at addition of 10 Vf-% Al2O3 reaches to 55 HRB. The percentages of porosity were increased for both composites along with the increase of particles reinforced. The microstrutures for both composites are similar since they have the same matrix and Sr clearly changed primary Mg2Si become finer chinese scripts, while TiB as grain refiner worked efficiently for higher reinforced particles addition because the grain size reduced for both composites.

Nano SiC-reinforced aluminumA356 (A356/SiC) has been successfully fabricated using stir casting method. The specimen was fabricated by adding various Nano SiC concentrations, i.e. 0, 0.10, 0.15, 0.20, 0.25, and 0.30 wt.%, at fix 1 wt.% magnesium into aluminum A356 melt. After stirring at certain time, the mixture was poured into the mold that has been preheated at 350oC for 5 minutes. The mechanical properties were characterized using tensile, hardness, and wear testing, where as the microstructural observation was performed using an optical microscope. The results show that the mechanical properties were optimum at 0.25 wt.% Nano SiC with a strength of 175.57 MPa (21.87%), toughness of 0.0287 Joules/mm3(14.8%), hardness of 56.54 HBN (50%), and wear resistance of 1.75 x 10-5 mm3/mm (21.13%). These results indicate that the fabrication approach was successful in producing cast MMCs samples and the use of Nano SiC and Magnesium as a wetting agent with continuous stirring were found to promote the wettability of SiC and A356 matrix alloy and thus result in reasonable mechanical properties of the composite.

Used of carbon pyrolyzed from table sugar in the synthesis of LiFe(1-x)VxPO4/C for lithium ion battery cathode has been examined. The process was begun by synthesizing LiFePO4through a hydrothermal method with the precursors of LiOH, NH4H2PO4and FeSO4.7H2O. The as-synthesized LiFePO4was then mixed with various H4NO3V concentrations and fixed 3 wt.% of carbon pyrolyzed from table sugar and calcined for 2 hours at 400 °C. The result was ball-milled and was then characterized using a thermal analyzer to determine the transition temperature at which sintering temperature of 700 °C for 4 hours was obtained. X-ray diffraction (XRD) was performed to analyze the crystal structure whereas scanning electron microscope (SEM) was used to examine the microstructure and surface morphology. XRD results show that LiFe(1-x)VxPO4/C phase has been formed with an olivine-based structure. SEM results showed an even distribution of LiFe(1-x)VxPO4/C particles. The batteries were prepared from the as-synthesized materials and were tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge and discharge (CD) tests. The EIS results showed that carbon improved the conductivity. The performance test showed that the addition of vanadium resulted in a capacity of about 51.06 mAh/g with a potential of 3.581 V at charging and 49.42 mAh/g with a potential of 3.319 V at discharging. These results are promising in terms of using table sugar as a cheap carbon source for lithium ion battery cathode development.

Lithium titanat Lithium titanate (Li4Ti5O12)/LTO is one of more favourable materials to be used as anode electrode to replace graphite in Li-ion battery application. The LTO has a crystal structure that is more stable than graphite, and undergoes less strain during lithium intercalation process. However, along with the increasing demand for batteries with high performance, the capacity of LTO also needs to be increased, among others by combining with a high capacity material, i.e: silicon, which theoretical capacity can reach 4200 mAh/g, but with volumetric strain of 300%. To minimize volume expansion effect, nanoscale silicon particle is used to form the LTO/Si nanocomposite. This research is carried out to synthesize the spinel LTO prepared by hydrothermal and mechanochemical process from xerogel TiO2. During preparation of slurry mixture of active material to make anode sheet, the LTO is mixed with silicon nanoparticle at 5%, 10% and 15% by weight. The coin cell type battery is assembled with lithium metal as the counter electrode. The material characterization instruments used are X-Ray diffraction (XRD) and Transmission Electron Microscope (TEM) with Energy Dispersive Spectrometer (EDS) showing the elements mapping. The battery performance is tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge discharge (CD). From EIS testing, the conductivity values of the samples decrease along with the increasing weight of Si nanoparticles. The CV test shows that the highest capacity of 197.09 mAh/g is achieved on the sample with 5wt% Si-nano. The CD test shows that this LTO/Si nanocomposite is capable to withstand at high charge/discharge rate at until 12 C exceeding the electric car battery requirement at 10 C.

The lithium-ion battery is a battery that is being developed to become a repository of energy, particularly for electric vehicles. Lithium titanate (Li4Ti5O12) anodes are quite promising for this application because of its zero-strain properties so it can withstand the high rate. However, the capacity of LTO (Li4Ti5O12) is still relatively low. Therefore, the LTO needs to be combined with other materials that have high capacity such as Si. Silicon has a very high capacity which is 4200 mAh/g, but it has a high volume of the expansion. Nano-size can also help increase the capacity. Therefore composite of LTO/nano Si is made to create an anode with a high capacity and also stability. Nano Si is added with a variation of 1, 5, and 10%. LTO/nano Si composite is characterized using XRD, SEM-EDX, and TEM-EDX. Then, to determine the battery performance, EIS, CV, and CD tests were conducted. From those tests, it is studied that Si improves the conductivity of the anode, but not significantly. The addition of Si results a greater battery capacity which is 262.54 mAh/g in the LTO-10% Si. Stability of composite LTO/nano Si is good, evidenced by the coulomb efficiency at the high rate of close to 100%.

A356/Al2O3 composites with Sr modifier were produced by stir casting process. The composites were further heat treated to obtain light material with superior characteristics through precipitation hardening of Mg2Si precipitate. The A356 alloy is reinforced with 10 %Vf Al2O3 micro particles. Small amount of Sr is added to modify eutectic silicon morphology from plate-like into fibrous. The composites were prepared by stir casting method in order to obtain dispersed reinforcement particulates within the matrix. T6 heat treatment is employed to the fabricated composites for 2, 4, 6, 8, and 10 hours of aging time to improve the properties. The result reveals that an optimum values of tensile strength, impact strength, hardness and wear rate are achieved by conducting 6 hours of aging. Longer than that, the properties will decline as a result of incoherent phase domination. Small amount of Sr is shown to be able to change the morphology of eutectic silicon from plate-like into fibrous. However, Fe-intermetallics formation, porosity, and negative effect from solution treatment due to improper technical condition during heat treatment are found to contribute on deterioration of mechanical properties of the material.

Renewable energy is a solution to overcome the negative effects of non-renewable energy due to very low carbon emissions and abundant availability on earth, such as, batteries. Battery development is done by increasing the capacity of the anode or cathode on the battery. The purpose of this research is to improve the performance of Li4Ti5O12 (LTO) battery anodes using the solid-state method with the addition of Sn nanoparticles (∼10 nm) and graphite as a composite material. Three variations of the addition of Sn nanoparticles besides of 10 wt.%, 15 wt.%, 20 wt.%, and 5 wt.%. Graphite in each variation, each marked as a sample of LTO/C-Sn nano 10 wt.%, LTO/C-Sn nano 15 wt.%, and LTO/C-Sn nano 20 wt.%. LTO synthesis with the solid-state method starts the sintering process for 6 hours at 850 ℃ then mixing graphite and Sn nanoparticles at the LTO anode is done mechanically. Characterization carried out were XRD, SEM-EDS, CV, CD, and EIS to see the structure, morphology, and performance of the battery anode. Based on the results of the battery characterization obtained the best crystallinity at the LTO/C-Sn nano 10 wt.% anode is 69.19 nm. In testing battery performance for specific capacity (CV) and storage (CD) value on the LTO/C-Sn nano 10 wt.% anode, the best value is 207 mAh/g and 1.5 %. The best conductivity value is the LTO/C- Sn nano 15 wt.% anode with a resistivity of 46.97 Ω.

Aluminum matrix composite (AMC) was one of the promising materials for railway brake shoe, replacing gray cast iron since it has a low density and great combination between strength and wear resistance. The addition of boron carbide (B4C) which reinforced aluminum ADC12 as matrix showed better interfacial bonding than other ceramic reinforcement such as silicon carbide and alumina. However, B4C has some serious problem when used in a large amount which will decrease the wetting properties. In this study, the fabrication of AMC was carried out with the addition of 1 to 10 vf.% reinforcement through stir casting and 2 minutes argon degassing process. Magnesium as a wetting agent, Titanium-boron as a grain refiner, and strontium as a modifier were added to improve its mechanical properties. Microstructure and mechanical properties of AMC were investigated by performing Optical Microscope (OM), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and destructive test. The result showed that the addition of 7 vf.% B4C was the optimum variation which increased the tensile strength with the value of 231.117 MPa and hardness of 58.34 HRB also decreased impact resistance with value of 0.09375 J/mm2 and wear rate 0.00326 x 10-5 mm/m3.