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Abstrak :
Titanium dan paduannya menjadi salah satu material pilihan untuk manufaktur beragam objek, terutama pada implan karena sifat mekanik, biokompatibilitas, dan ketahanan korosinya. Titanium dan paduannya dapat difabrikasi menggunakan beragam metode seperti Selective Laser Melting yang memakan waktu singkat dan waste-nya yang sedikit namun kekurangannya adalah getas. Salah satu cara meningkatkan ketangguhan dan keuletannya adalah dengan perlakuan panas. Hasil penelitian ini menunjukkan efek perlakuan panas pada suhu 900 C selama 2 jam menghasilkan mikrostruktur dominan berfasa α-Ti kolumnar yang memiliki nilai kekerasan 656 HV, sedangkan HT pada suhu 900 C selama 1 jam dilanjut di 550 C selama 2 jam menghasilkan mikrostruktur dan hasil XRD yang mengindikasikan campuran α dan β-Ti dengan kenaikan kekerasan menjadi 665 HV. Perlakuan panas yang lebih lama yaitu pada 900 C selama 2 jam dan 550 C selama 2 jam dan 900 C selama 2 jam dilanjut dengan 550 C selama 3 jam menunjukkan mikrostruktur dominan berfasa α-Ti ekuiaksial, dengan nilai kekerasannya menurun menjadi 622 HV dan 593 HV. ......Titanium and its alloy have become a material of choice for manufacturing various objects, particularly implants, due to their mechanical properties, biocompatibility, and corrosion resistance. Titanium and its alloys can be fabricated using various methods such as Selective Laser Melting, which is time-efficient and produces minimal waste, though its drawback is brittleness. The closest approach to enhancing the toughness and ductility of the SLM product is through post- processing by heat treatment. This study shows that heat treatment process which is done at 900°C for 2 hours holding resulting in a microstructure dominated by columnar α-Ti phase with a hardness value of 656 HV. Another heat treatment process is performed at 900° for 1 hour holding followed by 550°C for 2 hours holding, resulting in a microstructure and XRD which indicates a mixture of α and β-Ti with an increase in hardness to 665 HV. A longer heat treatment process is conducted at 900°C for 2 hours holding followed by 550°C for 3 hours holding, which shows a domination of equiaxed α-Ti phase in its microstructure, with a decrease in hardness to 622 HV and 593 HV.

Abstrak :
Karakterisasi sifat oksidasi dilakukan pada dua jenis material pada kondisi siklik dengan temperatur 1100 C, yaitu : (i) Inconel 625 Superalloy yang dihasilkan melalui metode Selective Laser Melting, kemudian dilapisi NiCrAlY dengan metode Selective Laser Melting, yang disebut sebagai sampel SLM; (ii) Inconel 625 superalloy yang dihasilkan melalui metode Selective Laser Melting, kemudian dilapisi CoNiCrAlY dengan metode Air Plasma Spray, yang disebut sebagai sampel APS. Analisa thermogravimetri dan struktur mikro dilakukan untuk mengetahui morfologi dan sifat lapisan oksida yang tumbuh di atas permukaan bond coat, pengelupasan lapisan oksida dan bond coat dan kinetika oksidasi. Dari analisa tersebut ditemukan bahwa kedua sampel mengalami kinetik oksidasi linier dan parabolik serta kedua jenis bond coat membentuk lapisan oksida yang sama, yaitu lapisan oksida Cr2O3 sebagai lapisan terluar, dan lapisan oksida a-Al2O3 sebagai lapisan dalam. Sebagian besar pengelupasan pada sampel SLM mungkin disebabkan oleh retak geser tekan di lapisan oksida sebagai akibat perbedaan koefisien ekspansi panas antara lapisan oksida dan bond coat, sedangkan sebagian besar pengelupasan pada sampel APS mungkin disebabkan oleh cacat porositas dan rongga udara di bond coat. Sampel SLM memiliki ketahanan oksidasi yang lebih baik daripada sampel APS dimana laju kinetik oksidasi parabolik sampel SLM sebesar 1.7053 x 10-6 g2 cm-4 s-1 , dan sampel APS sebesar 3.8969 x 10-6 g2 cm-4 s-1. ...... The characterization of oxidation behaviour is performed on two types of material in cyclic conditions with temperature of 1100 C i.e. (i) Inconel 625 fabricated using selective laser melting method, then is coated by NiCrAlY using selective laser melting method, called by SLM sample, and (ii) Inconel 625 fabricated using selective laser melting method, then is coated CoNiCrAlY using air plasma spray method, called APS sample. Microstructural and thermogravimetric analysis are used to know the morphology and nature of oxide scale formed on surface of bond coat, spallation of bond coat and oxide scale, oxidation kinetics. Those analysis reveal that both types of material exhibit the linier and parabolic oxidation kinetics, furthermore both bond coats form the similar oxide scale i.e. Cr2O3 scale as outer scale and a-Al2O3 as inner scale. Most spallations of SLM sample are likely caused by the compressive shear crack in the oxide scale as a result of the bond coat-oxide thermal expansion coefficient mismatch, while most spallations of APS sample are probably caused by the porosities and voids in the bond coat. SLM sample has the better oxidation resistance than APS sample where the parabolic oxidation kinetic rate of SLM sample of 1.7053 x 10-6 g2 cm-4 s-1 , and APS sample of 3.8969 x 10-6 g2 cm-4 s-1.

Abstrak :
Selective laser melting (SLM) has established itself as the most prominent additive manufacturing (AM) process for metallic structures in aerospace, automotive and medical industries. For a reliable employment of this process, it has to conform to the demanding requirements of these industries in terms of quasistatic and, especially, fatigue performance. Shafaqat Siddique identifies the influence of SLM processing conditions on the microstructural features, and their corresponding influence on the mechanical behavior of the processed AlSi12 alloy structures. The author also gives insight into integrated manufacturing by combining conventional and SLM processes to get the synergic benefits. Requirements for fatigue-resistant designs in additive manufacturing are highlighted, and a novel method is developed for agile fatigue life prediction.

Abstrak :
This book showcases different processes of fabrication and processing applied to shape memory alloys. It provides details and collective information on working principles, process mechanisms, salient features, novel aspects, process capabilities, properties of material and unique applications of shape memory alloys. The recent progress on fabrication and processing are specially addressed in this book. It covers major topics of manufacturing such as machining, joining, welding and processing of shape memory alloys.