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Piston merupakan salah satu komponen yang sangat penting bagi sebuah kendaraan. Di dalam sebuah industri, pembuatan piston dilakukan dengan cara pengecoran atau casting. Dalam proses pengecoran terdapat banyak fenomena umum yang tidak dapat dikontrol secara langsung seperti distribusi temperatur, tegangan termal, penyusutan serta deformasi cetakan. Oleh karena itu digunakan ANSYS Mechanical APDL yang berbasis metode elemen hingga untuk memprediksi fenomena dalam proses pengecoran. Digunakan pasir silika sebagai cetakan pasir dan SS304 sebagai permanent mold. Bahan coran yang digunakan adalah AL-12%Si. Ukuran piston Ninja 250R dijadikan referensi pada simulasi ini dimana memiliki dimensi bore dan stroke sebesar 62 mm dan 41.2 mm. Di dalam penelitian ini didapatkan pola distribusi temperatur serta tegangan termal dan juga shrinkage yang terjadi selama proses pengecoran dari kedua cetakan tersebut. Didapatkan nilai tegangan termal maksimum serta shrinkage sebesar 3.89E+09 Pa dan 31135.5 mm 3 pada keseluruhan cetakan SS304 sedangkan pada keseluruhan cetakan pasir adalah 2.35E+08 Pa dan 600 mm 3. Untuk bagian coran nilai tegangan termal maksimum dan shrinkage pada cetakan SS304 adalah 65228892.2 Pa dengang shrinkage sebesar 6.9457 mm 3 dan pada cetakan pasir sebesar 258718.871 Pa dan 0.0245 mm 3. Kata Kunci-Al-12%Si, analisa elemen hingga, distribusi temperatur, pengecoran, shrinkage, tegangan termal

Aluminum is a light metal with good electrical conductivity and widely applied for electrical devices. One of its application is the circuit breaker component. The 2xxx series of aluminum alloy has a copper alloying element which increases its mechanical properties and improves quality of electrical conductivity. This research aims to obtain the best gating system design of the circuit breaker mold by ANSYS modeling. This research also is subject to measure the influence of Cu alloying to the rate of electrical conductivity, strength, and hardness in aluminum alloys for circuit breaker application by experimental working. Aluminum is alloyed with variations of 1; 2; 3; 4; and 5% copper addition. Modeling of thermal analysis and structural analysis was calculated by ANSYS Mechanical APDL with a finite element method to find the best design for the sand casting experiments. Chemical composition, metallography, brinnel hardness, tensile, XRD, and electrical conductivity tests were conducted in this study. The highest strength is 59.50 MPa was acquired on Al-3% Cu while the lowest strength is 37.43 MPa was on Al-1% Cu alloy. The peak of hardness 48.70 HBN could be drawn at Al-4% Cu. In the other hand, the dip of it was Al 1% Cu of 25.5 HBN. The last variable, conductivity, has the highest amount as of Al-5C, alloys with a value of 12.88 S / M, which is found on Al-1Cu with a value of 9.30 S/m.

Deep drawing has become the most general method in cartridge manufacturing process which use brass alloy as the main component. To perform deep drawing on this type of alloy, there are several physical and mechanical properties re-quired, especially the ductility and hardness. In this paper, the CuZn35 brass alloy, which still does not fulfill the requirements, had been annealed in the several annealing parameters (holding time and annealing temperature) to achieve the re-quired properties. It also discussed the microstructure evolution in every annealing parameter and the affiliation to its mechanical properties. The temperature annealing process of CuZn35 brass alloy was conducted in 300, 400, 500, and 600°C for 60 minutes. Then, the heat-treated product will be observed to get the composition, microstructure, hardness, strength, and also deep drawing formability. The-ꞵ precipitation was successfully eliminated by annealing process which significantly decrease its hardness and tensile strength whereas the increased grain size affect the ductility.