Analisis Karakteristik dan Kekerasan Lattice Structures Aluminium 7075 Hasil Modifikasi Investment Casting Metode Pre-Heated Mold

Anjarsari, Retno (2025) Analisis Karakteristik dan Kekerasan Lattice Structures Aluminium 7075 Hasil Modifikasi Investment Casting Metode Pre-Heated Mold. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Cellular material berbahan dasar logam memiliki ketangguhan dan kekuatan yang baik, serta ringan karena strukturnya yang berpori sehingga pemanfaatan metallic cellular materials (MCMs) lebih luas. Salah satu metode fabrikasi metallic cellular materials yang memungkinkan adalah menggunakan Selective Laser Melting (SLM) dengan kelemahan dari metode SLM ini adalah ketersediaan alat di seluruh dunia, bahan serbuk aluminium yang mahal, serta alat yang cukup mahal. Salah satu metode konvensional untuk memfabrikasi MCMs adalah investment casting. Additive manufacturing metode FFF merupakan cara pembuatan 3D model menggunakan material polimer. Dengan menggabungkan metode FFF dan investment casting lebih menghemat biaya, waktu, konsumsi dan energi produksi, serta ramah lingkungan tanpa mengurangi kualitas pengecoran metode investment casting. Tujuan dilakukannya penelitian ini adalah untuk menganalisis lattice structures dengan metode fused filament fabrication serta menganalisis pengaruh diameter strut lattice structures truncated octahedron terhadap karakteristik dan kekerasan hasil pengecoran aluminium 7075 dengan metode pre-heated cetakan. Fused filament fabrication digunakan untuk mencetak pola lattice structures dengan variasi diameter strut 4,6 mm, 4,8 mm, dan 5 mm yang kemudian dibenamkan ke dalam slurry. Setelah itu pola di evaporasi di dalam furnace sehingga menjadi cetakan, kemudian cetakan dipanasi pada temperature 400-450oC. Lelehan aluminium 7075 dituangkan pada cetakan yang telah di pre-heat dan tanpa pre-heat. Lattice structures truncated octahedron yang difabrikasi menggunakan metode FFF dengan material filamen PLA berhasil difabrikasi sesuai dengan gambar CAD. Semakin besar diameter strut, maka jumlah lattice yang terbentuk semakin banyak. Apabila dilihat dari jumlah cacat yang terjadi dan jumlah lattice yang terbentuk, semakin besar diameter strut, semakin sedikit cacat yang terjadi dan lattice yang terbentuk semakin sempurna. Hasil pengujian metalografi menunjukkan bahwa pada posisi pengambilan data yang sama, semakin beasr diameter strut, grain size semakin besar. Hal ini sesuai dengan hasil pengujian kekerasan, dimana semakin besar diameter strut maka nilai kekerasan dari posisi pengambilan yang sama semakin rendah. Semakin besar grain size, maka nilai kekerasan semakin rendah.
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Metal-based cellular materials have good toughness and strength, and are lightweight due to their porous structure so that the utilization of metallic cellular materials (MCMs) is more extensive. One of the possible fabrication methods of metallic cellular materials is using Selective Laser Melting (SLM) with the disadvantages of this SLM method is the availability of tools worldwide, expensive aluminum powder materials, and quite expensive tools. One of the conventional methods to fabricate MCMs is investment casting. Additive manufacturing FFF method is a way of making 3D models using polymer materials. By combining the FFF and investment casting methods, it will save costs, time, production consumption and energy, and be environmentally friendly without reducing the casting quality of the investment casting method. The purpose of this research is to analyze lattice structures with the fused filament fabrication method and analyze the effect of the diameter of the truncated octahedron lattice structures strut on the characteristics and hardness of 7075 aluminum castings with the preheated mold method. Fused filament fabrication is used to print patterns of lattice structures with variations in strut diameter of 4.6 mm, 4.8 mm, and 5 mm which are then immersed in slurry. After that, the pattern is evaporated in the furnace so that it becomes a mold, then the mold is heated at a temperature of 400-450oC. The 7075 aluminum melt was poured into preheated and non-heated molds. The truncated octahedron lattice structures fabricated using the FFF method with PLA filament material were successfully fabricated according to the CAD drawings. The larger the strut diameter, the greater the number of lattices formed. When viewed from the number of defects that occur and the number of lattices formed, the larger the strut diameter, the fewer defects that occur and the more perfect the lattice formed. Metallographic test results show that at the same data collection position, the larger the strut diameter, the larger the grain size. This is consistent with the results of hardness testing, where the larger the strut diameter, the lower the hardness value from the same retrieval position. The larger the grain size, the lower the hardness value.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Aluminum 7075, Fused filament fabrication, Investment casting, Truncated octahedron, Aluminium 7075
Subjects:	T Technology > TN Mining engineering. Metallurgy > TN775 Aluminum alloys--Metallurgy. T Technology > TS Manufactures > TS233 Sand casting. Metal castings--Thermal properties.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Retno Anjarsari
Date Deposited:	17 Jan 2025 07:08
Last Modified:	17 Jan 2025 07:08
URI:	http://repository.its.ac.id/id/eprint/116371

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