PENGARUH PENAMBAHAN UNSUR Al DAN MEDIA PENDINGIN CETAKAN TERHADAP SIFAT MEKANIK DAN STRUKTUR MIKRO PADUAN Cu-Al DENGAN METODE PERMANENT MOLD CASTING
Daftar Isi:
- Copper and its alloys are commonly used as materials for electronic devices because of their properties, including electrical and thermal conductivity. The more copper is used, the more waste there is. Therefore waste copper must be recycled. Copper is commonly combined with other elements to improve its mechanical properties. One of them is aluminum to improve mechanical properties, including strength and hardness. Conventionally, Cu-Al alloys are usually produced by casting, one of which is for the manufacture of propellers. However, if using conventional casting such as the sand casting method, there are still many defects in the casting results. So in this study, the permanent mold casting method was chosen. Copper waste is casted by adding variations in weight percent of Aluminum so that it becomes a Cu-Al Alloy using the permanent mold casting method which is varied with the cooling media of the mold. The addition of Aluminum aims to improve the mechanical properties of copper with various additions in weight percent of 1%, 3% and 5%. While the variation of mold cooling media aims to determine the effect of cooling on the rate of freezing of castings, mechanical properties and microstructure with variations of the cooling media used in the form of air, wet sand and water. All casted at a temperature of 12000C until melted and then poured into a mold that has been given a cooling medium for the mold to freeze. Analysis of mechanical properties was carried out by testing the hardness using the Hardness Vickers method and testing the wear (wear test) using the ogoshi method. Microstructure analysis using optical microscope and ImageJ application. After the research was conducted, it was found that the addition of aluminum can improve the mechanical properties of copper, namely hardness and wear. The cooling medium of the mold also improves the mechanical properties of copper and affects the microstructure, which is to restrain grain growth so that the grain size becomes smaller. The best hardness results are 214,047 HV, the best abrasion specification value is 3,031908 x 10-6 mm3/mm and the best grain size is 29,787 μm with the addition of 5% Aluminum and the use of water mold cooling media.