Aluminium matrix composites (AMCs) are widely used in various applications because of their excellent properties; however, their lightweightness limits their broad application scope. Various ceramic compounds are used as reinforcements in AMCs, such as Al 2 O 3 , SiC, ZrO 2 , and TiO 2 . However, the use of ceramic compounds results in high production costs in AMC manufacturing. Thus, the substitution of reinforcement particles with various organic and industrial waste reinforcements is required. In line with the research trend of using industrial waste materials such as rice husk ash, red mud, and fly ash, this study uses sea sand as an AMC reinforcement. Sea sand is used because it primarily contains SiO 2 and Fe 3 O 4 ceramic compounds and, thus, can be used as a reinforcement. This study aims to determine the physical and mechanical properties of an AA6061–sea sand composite. Sea sand was subjected to electroless coating to increase its wettability before the stir-casting process. The as-prepared composite was manufactured by the stir-casting method upon the addition of 2–6 wt% sea sand. Composite characterisation was carried out through Brinell hardness and tensile tests. The results showed that the electroless-coated composites possessed lower porosity and, therefore, higher hardness and ultimate tensile strength than the non-electroless-coated composites.

Abstract.The automotive world is a world where one of the factors that must be considered carefully is the safety aspect. In the formula student car one of the safety factor in the form of impact attenuator. Impact attenuator is used as anchoring when a collision occurs in front of the vehicle. In the rule of formula society of automotive engineer (FSAE) student, impact attenuator is required to absorb the energy must meet or exceed 7350 Joules with a slowdown in speed not exceeding 20 g average and peak of 40 g. The student formula participants are challenged to pass the boundaries so that in designing and making the impact attenuator must pay attention to the strength and use of the minimum material so that it can minimize the expenditure. In this work, an impact attenuator was fabricated and tested using static compression. The primary goal was evaluating the actual capability of the impact attenuator for impact energy absorption. The prototype was made of aluminum alloy in a prismatic shape, and the inside wall was filled with rooftop plastic slices and polyurethane hard foam. The compression test has successfully carried out, and the load versus displacement data could be used in calculating energy absorption capability. The result of the absorbent energy of the selected impact attenuator material. Impact attenuator full polyurethane absorbed energy reach 6380 Joule. For impact attenuator with aluminum polyurethane with a slashed rooftop material as section absorbed energy reach 6600 Joule. Impact attenuator with Aluminum Polyurethane with aluminum orange peel partitions absorbed energy reach 8800 Joule. From standard student formula, energy absorbed in this event must meet or exceed 7350 Joules that meet aluminum polyurethane with aluminum orange peel partitions with the ability to absorb 8800 Joule.

The increasing demand for lightweight material specifications has forced researchers to develop lightweight materials that are inexpensive, can be produced on a large scale, and are environmentally friendly. One solution that has been developed is an aluminum composite reinforced with sea sand. Indonesia has the second longest coastline in the world, which means that the country is rich in maritime resources, one of which is sea sand. The ceramic contents of SiO2, SiC, and Al2O3allow sea sand to be used as a reinforcement in aluminum composites for engineering purposes. The most effective manufacturing method of AA6061–sea sand composites is stir casting, but the homogeneity and distribution of particles are the main disadvantages of the stir casting method. Various factors affect particle distribution and homogeneity, one of which is the flow during the stirring process. The increase in turbulent flow in the stirring process affects the homogeneity and distribution of the particles. One way to create a turbulent flow when stirring is to add baffles. This paper examines the effect of adding baffles during the stir casting process on the mechanical properties of AA6061–sea sand composites. The mechanical properties of AA6061–sea sand composites were characterized using the Brinell hardness test according to ASTM E-10. The test results show that the addition of baffles during the stir casting process decreases the hardness of the AA6061–sea sand composites due to the turbulent flow that occurs. This makes the material more porous, which makes the AA6061–sea sand composites less hard. Doi: 10.28991/CEJ-2022-08-08-04 Full Text: PDF