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"Phase trnasformation temperature of shape memory alloy - Tini produced by arc - melting technique. The observation of phase trnasformation temperature of Tini alloys produced by arc - melting technique was carried out by alloying Ti - 53%w Ni. Tini alloys were tempered at 900oC and then followed by quenching at 20oC and 5oC and finally were aged at 400oC for 1,4 and 16 hours. The Ti-53%. Ni alloyed is applied to obtain as shape memory alloys base on Tini . The Tini sample was analyzed by optical microscope, X - ray diffraction and simultaneous symmetrical thermoanalyzer (STA) . The result show that the martensitic phase has a structure of BCT (bODY CENTER TETRAGONAL) formed at room temperarure. The phase transformation temperature from martensitic - austensitic phase was taken place at (162+5)oC"

"Theory of arched structures : strength, stability, vibration presents detailed procedures for analytical analysis of the strength, stability, and vibration of arched structures of different types, using exact analytical methods of classical structural analysis. The material discussed is divided into four parts. Part I covers stress and strain with a particular emphasis on analysis. Part II discusses stability and gives an in-depth analysis of elastic stability of arches and the role that matrix methods play in the stability of the arches. Part III presents a comprehensive tutorial on dynamics and free vibration of arches, and forced vibration of arches. Part IV offers a section on special topics which contains a unique discussion of plastic analysis of arches and the optimal design of arches."

"Aluminium adalah sebuah logam ringan dan ulet yang memiliki kegunaan terbanyak kedua di dunia industri setelah besi dan baja. Salah satu paduan aluminium yang memiliki aplikasi luas adalah Al-Mg-Si yang termasuk ke dalam seri aluminium 6xxx. Peningkatan kekuatan paduan AlMg-Si dapat dilakukan melalui perlakuan penuaan dan pengerjaan panas, dimana kedua proses tersebut dapat digabungkan sehingga menghasilkan perlakuan yang disebut perlakuan panas T5. Penelitian ini menggabungkan metode canai panas yang dilakukan saat perlakuan pelarutan kemudian diikuti dengan penuaan pada paduan Al-1,01Mg-0,58Si (% berat) yang dihasilkan lewat proses squeeze casting. Pencanaian panas dilakukan pada temperatur 400, 475, dan 550 °C dengan persen deformasi sebesar 10 %, sementara itu penuaan buatan dilakukan pada temperatur 180 °C selama 0-200 jam. Karakterisasi meliputi pengujian komposisi kimia, pengujian kekerasan, pengamatan metalografi dan SEM – EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy), serta pengujian XRD (X-Ray Diffraction). Hasil penelitian menunjukkan bahwa kenaikan temperatur pemanasan atau laku pelarutan meningkatkan pelarutan fasa kedua, mempercepat peristiwa rekristalisasi dinamis, serta memicu respons penuaan yang lebih baik. Hal ini ditunjukkan dengan fenomena yang terjadi, pada kondisi setelah pencelupan cepat, paduan Al yang diberikan pencanaian panas pada temperatur 400 dan 475 °C mengalami peristiwa pemulihan, sementara pada 550 °C sudah terjadi rekristalisasi. Selanjutnya pada kondisi setelah penuaan, paduan Al hasil pencanaian panas pada temperatur 550 °C yang diikuti penuaan pada temperatur 180 °C selama 8 jam menghasilkan kekerasan yang paling tinggi diantara perlakuan lainnya.

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Aluminum is a light and ductile metal which has the second most uses in industrial world after iron and steel. One aluminum alloy that has wide application is Al-Mg-Si which belongs to the aluminum 6xxx series. Increasing the strength of Al-Mg-Si alloys can be done through ageing treatment and hot working, which can be combined to produce T5 heat treatment. This research combined hot rolling with solution treatment followed by ageing, which was applied on Al-1.01Mg-0.58Si (Wt. %) alloy produced through the squeeze casting process. The temperatures of hot rolling were varied to 400, 475, and 550 °C with a percent deformation of 10 %, meanwhile artificial ageing was carried out at 180 °C for 0-200 hours. The characterization included chemical composition testing, hardness testing, metallographic observation by optical microscope and SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy), as well as XRD (X-Ray Diffraction) testing. The results showed that an increased in heating or solution treatment temperature increased the dissolution of the second phase into the matrix, accelerate dynamic recrystallization event, and trigger a better ageing response. This is showed by phenomenon that occurred, on the as-quenched condition, only recovery occurred to alloy that was given hot rolling at temperature of 400 and 475 °C, while at 550 °C the recrystallization occurred. On the as-aged condition, the alloy that was given hot rolling at 550 °C followed by ageing at 180 °C for 8 hours exhibits a higher hardness than other treatments."

"Komposit matrik keramik (CMCs) sebagai salah satu material yang terus menerus dikembangkan dan disempurnakan sifat-sifatnya merupakan bahan alternatif pengganti logam yang potensial. Alasan utama untuk mengembangkan CMCs adalah karena kemampuannya untuk memberikan sifat yang bisa diaplikasikan pada aplikasi temperatur tinggi. Karakteristik material CMCs dipengaruhi oleh temperatur proses, waktu tahan, prosentase magnesium dan volume fraksi penguat. Oleh karena, itu penelitian ini menekankan pada pengaruh temperatur proses dan prosentase magnesium terhadap karakteristik. CMCs A1203/A1 hasil proses Directed Metal Oxidation. Material yang digunakan adalah Aluminium ingot, serbuk A1203 dan serbuk magnesium sebagai dopan. Pada penelitian ini, temperatur proses yang digunakan adalah 1100 °C, 1200 °C, 1300 °C , waktu tahan 15 jam dan prosentase magnesium yang digunakan adalah 4%, 8%, 10% dan 12% sedangkan proses pembuatan CMCs pada sebuah tray dengan metode Directed Metal Oxidation (D1MOX). Hasil fabrikasi diamati pengaruh temperatur proses dan prosentase magnesium terhadap sifat-fisis. Hasil penelitian menunjukkan terjadi penurunan kekerasan, densitas pada temperatur proses dan prosentase magnesium yang semakin meningkat Sebaliknya terjadi peningkatan laju keausan, porositas dan ekspansi termal pads temperatur proses dan prosentase magnesium yang semakin meningkat."

"Aluminium adalah sebuah logam ringan dan ulet yang memiliki kegunaan terbanyak kedua di dunia industri setelah besi dan baja. Salah satu aluminium yang memiliki aplikasi yang luas adalah paduan Al-Mg-Si yang tergolong ke dalam aluminium seri 6xxx. Walaupun memiliki banyak keunggulan, paduan Al-Mg-Si memiliki kekurangan yaitu nilai kekerasannya yang rendah jika dibandingkan dengan aluminium seri lainnya. Oleh karena itu, peningkatan nilai kekerasan pada paduan Al-Mg-Si dapat dilakukan melalui pengerjaan dingin dan perlakuan penuaan. Kedua proses tersebut dapat digabungkan sehingga menghasilkan perlakuan yang disebut dengan perlakuan panas T8. Penelitian ini menggabungkan metode canai dingin yang dilakukan setelah perlakuan pelarutan kemudian diikuti dengan penuaan buatan pada paduan Al-1Mg-0.54Si ( % berat) yang dihasilkan melalui proses squeeze casting. Canai dingin yang dilakukan menggunakan tiga variasi deformasi yaitu 5, 10, dan 20 %. Sementara itu, penuaan dilakukan pada temperatur 180 °C selama 200 jam. Pengujian yang dilakukan adalah pengujian komposisi kimia, pengujian kekerasan, pengujian metalografi, pengujian SEM–EDS (Scanning Electron Microscope – Energy Dispersive Spectroscopy), dan pengujian XRD (X-Ray Diffraction). Hasil penelitian menunjukkan bahwa semakin besar deformasi menyebabkan butir semakin memanjang dan setelah penuaan menghasilkan peningkatan kekerasan puncak yang dicapai pada waktu yang semakin singkat. Hal ini ditunjukkan dengan paduan Al-Mg-Si setelah dideformasi sebesar 20 % yang diikuti dengan penuaan pada temperature 180 °C selama 30 menit menghasilkan nilai kekeran yang paling tinggi. Hal ini mengindikasikan adanya kombinasi dua mekanisme penguatan, yaitu pengerasan regangan dan penguatan presipitasi.

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Aluminium is a light and ductile material that has the second most use in industry after iron and steel. One of the aluminium that has a wide application is the Al-Mg-Si alloy which classified as aluminium 6xxx series. Although it has many advantages, Al-Mg-Si alloy has a disadvantage, which is its low hardness value compared to other aluminium series. Therefore, increasing the hardness value of Al-Mg-Si alloys can be done through cold working and ageing treatment. The two processes can be combined to produce a treatment known as T8 heat treatment. This research combined the cold rolling method which was carried out after solution treatment followed by ageing of the Al-1Mg-0.54Si alloy (wt. %) which was produced through squeeze casting process. Cold rolling was varied to 5, 10, and 20 % deformation. Meanwhile, ageing was carried out at 180 °C for up to 200 h. Characterization included compositional testing, hardness testing, metallographic testing, SEM - EDS (Scanning Electron Microscope - Energy Dispersive Spectroscopy) testing, and XRD (X-Ray Diffraction) testing. The results demonstrated that the higher the deformation, the longer the grain elongated, and after ageing resulted in an increase in peak hardness which was achieved in a shorter time. This was demonstrated by the Al-Mg-Si alloy after 20 % deformation and ageing at 180 °C for 30 min, which produced the maximum hardness value. This suggests the presence of two strengthening mechanisms, which included strain hardening and precipitation strengthening."

"[Salah satu komponen terpenting pada peluru adalah selongsong yang memuat bubuk mesiu, primer, dan proyektil. Material yang umum digunakan untuk memfabrikasi selongsong peluru adalah cartridge brass (kuningan) yang mengandung 26-32 wt.% Zn. Selongsong peluru diproduksi dengan proses metalurgi yang kontinu, yang terdiri atas pengecoran, pencanaian, dan deep drawing. Dalam proses deep drawing biasanya ditemukan beberapa masalah mayor, seperti keretakan dan perobekan. Untuk meminimalisir masalah tersebut, pengembangan material dengan keuletan yang lebih baik menjadi penting untuk digunakan sebagai selongsong peluru. Mangan digunakan sebagai unsur paduan pada kuningan untuk meningkatkan keuletannya. Pada penelitian ini, paduan Cu-28Zn dengan penambahan 3,2 wt.% Mn difabrikasi dengan pengecoran gravitasi. Untuk menghomogenisasi komposisi kimia, paduan diberi perlakuan panas pada 800 oC selama 2 jam. Kemudian spesimen dicanai dingin dengan deformasi 20, 40, dan 70 % reduksi. Proses anil selanjutnya dilakukan setelah pencanaian dingin sebesar 70 % dengan temperatur 350, 400, dan 450 oC selama 15 menit. Karakteriasi material yang dilakukan pada penelitian ini terdiri dari analisis struktur mikro menggunakan mikroskop optik dan Scanning Electron Microscope (SEM) - Energy Dispersive Spectroscopy (EDS), serta pengujian kekerasan mikro. Hasil penelitian menunjukkan bahwa peningkatan derajat deformasi sebesar 20, 40, dan 70 % menyebabkan butir menjadi semakin pipih dengan L/D ratio masing-masing bernilai sekitar 0,7, 2,2, 7,7, dan 14,1. Selain itu juga terjadi peningkatan nilai kekerasan spesimen, yakni sebesar 56, 127, 145, dan 207 HV secara berurutan. Sementara proses anil setelah canai dingin sebesar 70 % pada temperatur 350, 400, dan 450 oC menyebabkan terjadinya peristiwa stress relieve yang ditandai dengan fenomena recovery, diikuti dengan rekristalisasi (dgrain ~ 7 μm), hingga grain growth (dgrain ~ 14 μm). Selain itu juga terjadi penurunan nilai kekerasan spesimen, yakni sebesar 204, 131, dan 100 HV secara berurutan. Pengaruh penambahan unsur Mn di dalam paduan cartridge brass adalah meningkatkan nilai kekerasan dan memperlambat laju rekristalisasi, dibutuhkan temperatur anil yang lebih tinggi untuk mencapai rekristalisasi sempurna pada paduan cartridge brass dengan penambahan Mn.

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One of the most important part of bullet is its cartridge shell which contains gun powder, primer, and projectile altogether. Common material used to fabricate bullet shell is cartridge brass which contains 26-32 wt.% Zn. Cartridge shell is produced by a continuous metallurgical processes, which are casting, rolling, and deep drawing. In deep drawing process, some major problems are typically found, such as cracking and tearing. In order to minimize these problems, it is essential to develop materials with enhanced ductility to be used as cartridge shell. Manganese is used as an alloying element of cartridge brass to increase its ductility. In this research, Cu-28Zn alloy with addition of 3,2 wt.% Mn were fabricated by gravity die casting. To homogenize the chemical composition, the alloy was heated at 800 °C for 2 hours. Afterwards, the specimens were cold-rolled with deformation of 20, 40, and 70 %. Subsequent annealing process after 70 % cold-rolled with temperature of 350, 400, and 450 oC for 15 minutes was carried out. Material characterizations consisted of microstructure analysis using optical microscope and Scanning Electron Microscope (SEM) - Energy Dispersive Spectroscopy (EDS), and microvickers hardness testing. The result showed that higher degree of deformation of 20, 40, and 70 % led to more elongated grains with L/D ratio of 0.7, 2.2, 7.7, and 14.1, respectively. Moreover, the hardness of material increased with the increase in the level of deformation, with the values of 56.1, 126.6, 144.6, and 206.7 HV, respectively. Meanwhile, annealing at the temperatures of 350, 400, and 450 oC to specimens with prior deformation of 70 %, resulted in recovery and stress relieve, followed by recrystallization (dgrain ~ 7 μm), and finally grain growth (dgrain ~ 14 μm). Furthermore, the hardness of material decreased with the increase in level of annealing temperature, with the values of 204, 131, and 100 HV, respectively. The roles of Mn in the cartridge brass is to increase the hardness and to slower the recrystallization rate. In general, addition of Mn in cartridge brass increased the annealing temperatures needed to achieve full recrystallization.;One of the most important part of bullet is its cartridge shell which contains gun powder, primer, and projectile altogether. Common material used to fabricate bullet shell is cartridge brass which contains 26-32 wt.% Zn. Cartridge shell is produced by a continuous metallurgical processes, which are casting, rolling, and deep drawing. In deep drawing process, some major problems are typically found, such as cracking and tearing. In order to minimize these problems, it is essential to develop materials with enhanced ductility to be used as cartridge shell. Manganese is used as an alloying element of cartridge brass to increase its ductility. In this research, Cu-28Zn alloy with addition of 3,2 wt.% Mn were fabricated by gravity die casting. To homogenize the chemical composition, the alloy was heated at 800 °C for 2 hours. Afterwards, the specimens were cold-rolled with deformation of 20, 40, and 70 %. Subsequent annealing process after 70 % cold-rolled with temperature of 350, 400, and 450 oC for 15 minutes was carried out. Material characterizations consisted of microstructure analysis using optical microscope and Scanning Electron Microscope (SEM) - Energy Dispersive Spectroscopy (EDS), and microvickers hardness testing. The result showed that higher degree of deformation of 20, 40, and 70 % led to more elongated grains with L/D ratio of 0.7, 2.2, 7.7, and 14.1, respectively. Moreover, the hardness of material increased with the increase in the level of deformation, with the values of 56.1, 126.6, 144.6, and 206.7 HV, respectively. Meanwhile, annealing at the temperatures of 350, 400, and 450 oC to specimens with prior deformation of 70 %, resulted in recovery and stress relieve, followed by recrystallization (dgrain ~ 7 μm), and finally grain growth (dgrain ~ 14 μm). Furthermore, the hardness of material decreased with the increase in level of annealing temperature, with the values of 204, 131, and 100 HV, respectively. The roles of Mn in the cartridge brass is to increase the hardness and to slower the recrystallization rate. In general, addition of Mn in cartridge brass increased the annealing temperatures needed to achieve full recrystallization., One of the most important part of bullet is its cartridge shell which contains gun powder, primer, and projectile altogether. Common material used to fabricate bullet shell is cartridge brass which contains 26-32 wt.% Zn. Cartridge shell is produced by a continuous metallurgical processes, which are casting, rolling, and deep drawing. In deep drawing process, some major problems are typically found, such as cracking and tearing. In order to minimize these problems, it is essential to develop materials with enhanced ductility to be used as cartridge shell. Manganese is used as an alloying element of cartridge brass to increase its ductility.

In this research, Cu-28Zn alloy with addition of 3,2 wt.% Mn were fabricated by gravity die casting. To homogenize the chemical composition, the alloy was heated at 800 °C for 2 hours. Afterwards, the specimens were cold-rolled with deformation of 20, 40, and 70 %. Subsequent annealing process after 70 % cold-rolled with temperature of 350, 400, and 450 oC for 15 minutes was carried out. Material characterizations consisted of microstructure analysis using optical microscope and Scanning Electron Microscope (SEM) - Energy Dispersive Spectroscopy (EDS), and microvickers hardness testing.

The result showed that higher degree of deformation of 20, 40, and 70 % led to more elongated grains with L/D ratio of 0.7, 2.2, 7.7, and 14.1, respectively. Moreover, the hardness of material increased with the increase in the level of deformation, with the values of 56.1, 126.6, 144.6, and 206.7 HV, respectively. Meanwhile, annealing at the temperatures of 350, 400, and 450 oC to specimens with prior deformation of 70 %, resulted in recovery and stress relieve, followed by recrystallization (dgrain ~ 7 μm), and finally grain growth (dgrain ~ 14 μm). Furthermore, the hardness of material decreased with the increase in level of annealing temperature, with the values of 204, 131, and 100 HV, respectively.

The roles of Mn in the cartridge brass is to increase the hardness and to slower the recrystallization rate. In general, addition of Mn in cartridge brass increased the annealing temperatures needed to achieve full recrystallization.]"