Abstract. The purpose of this study is to determine the effect of current variation in the anodizing process to aluminum oxide layer thickness and corrosion resistance. Aluminum with a purity of 97.34% is used in the anodizing process. The chemical composition of the test object is as follows: 97.34% Al, 0.034% Si, 0.46% Fe, 1.87% Mn, and 0.043% Cu. Work on early before anodizing process is the cleaning material mechanically with a brush and sandpaper, followed by chemical cleaning by dipping aluminum into the solution of nitric acid and hold for 10-20 seconds. After that, the process of etching (chemical milling) is conducted by using a soda (sodium hydroxide) to remove the natural luster on aluminum and then Desmutt process taken to eliminate smut or thin layers of gray to black from aluminum alloying elements that are not soluble in the cleaning and etching solution in aluminum. In this process the material is dipped into an acid solution florat 10-20 seconds. Anodizing process is performed by placing the aluminum to be anodized as an anode. Aluminum is immersed in an electrolyte solution of sulfuric acid 15%. Currents variation used for anodizing process are 1 Ampere, 2 Ampere and 3 Ampere, respectively, while, the voltage used is 30 Volt with immersion time of 40 minutes. To determine the thick oxide layer, observations is carried out on micro photograph specimens of anodizing results. From the observations, it can be concluded that the greater the current that is used, the larger the penetration of oxidation in specimens, and will increase layer of oxide thickness. Consequently corrosion resistant of aluminum is improved.

Purpose: The purpose of this work was to investigate the effect of arrow pattern tire compound on hardness, wear resistance and grip coefficient in dry and wet operation conditions. Methodology: The mixing compound would be consist of Rubber Smoked Sheet (RSS), Styrene Butadiene Rubber (SBR), Black Carbon, Paraffin oil, ZnO, Stearic Acid, Paraffin wax, Epoxy and Sulphur. The compound is mixed and heated to 100°C. After being cooled it is then conducted hardness test, performed wear test and tested for friction. Results: The hardness and the tensile strength of the tire compound increase with increasing black carbon composition. While the wear of the tire compound decrease with increasing black carbon composition. There were no significant differences of grip coefficient when black carbon increased. However, grip coefficient will decrease by 12% when operating conditions change from dry asphalt track to wet asphalt track. Applications/Originality/Value: The life of tire compound usage is increased by the addition of black carbon particles.

Composite particles are composites that contain particle or powder-shaped reinforcing materials. Particles as reinforcing materials greatly determine the mechanical properties of composites because they carry the load distributed by the matrix. The particle size, shape, and material are factors that influence the mechanical properties of particle composites. The friction component material that is intended for brake lining applications is strongly influenced by the size of the particles and the direction of loading. On the other hand it is necessary to step up the particle size optimization which will affect braking performance, which includes: friction numbers, wear, friction time and friction temperature produced. Therefore this study is aimed at optimizing the particle size against hardness, wear resistance and friction of aluminum powder in rice plant fiber reinforced composite. In this study, the materials used in the experimental process were rice plant fiber, fiberglass, aluminum powder and polyester resin. After the material is processed into the composite, hardness is tested using the durometer shore hardness method, after that, wear and friction testing were conducted. The results show the smaller the size of the aluminum powder, the harder the composite. The smaller the size of aluminum powder, the less wear of the composites. The failure of the adhesive was seen in the specimen tested for wear.

Asbestos type brake lining is widely circulating at a cheap price and guarantees the durability of brake shoes, but the result of friction powder in the form of small particles is very dangerous for human health. The study is based on the investigation of hardness and wear resistance in rice plant fiber reinforced composite which is fabricated with polyester resin, fiberglass, and addition of aluminium powder. The composite is hardness tested by using durometer shore D hardness tester. The composite is also wearing resistance tested. The result showed that the mechanical properties were improved due to the increasing of the rice plant fiber composition. The more composition of the rice plant fiber, the harder and the higher wear resistance of the composite. An increase in the composition of the rice plant fiber from 20% to 40% resulted in an increase in hardness of 23% and a decrease in wear by 9%

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