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"ABSTRAKHigh Tensile Brass (HTB) merupakan paduan antara Cu dan Zn, dimana kekuatan paduan ini ditingkatkan dengan penambahan unsur Aluminium (Al ), Mangan (Mn), Ferro (Fe).Dalam penelitian ini mencari pengaruh penambahan Ferro (Fe) dalam paduan HTB sebesar 4% dengan paduan tanpa Ferro (Fe) ditinjau dari sifat. mekanis maupun dengan struktur mikro. Sifat mekanis dan struktur mikro yang diperlakukan paduan HTB tersebut pada beberapa kondisi , yaitu kondisi as..cast., kondisi dicelup oli maupun air dan kondisi ditemper pada T 300ºc, T 500ºC, T 700ºC.Dari hasil penelitian didapat bahwa nilai optimum sifat mekanis dan struktur mikro tidak dapat diambil secara kondisi umum, tetapi harus dilihat untuk digunakan apa paduan HTB tersebut"

"Seeking to provide an introduction to those new to tensile testing as well as to those who need more detailed information to use in the course of professional practice. They start with the basics, including explaining the stress-strain curve and test methodology, then proceed to the mechanical behavior of materials under tensile loads.Contents :- Preface - Chapter 1: Introduction to tensile testing - Chapter 2: Mechanical behavior of materials under tensile loads - Chapter 3: Uniaxial tensile testing - Chapter 4: Tensile testing equipment and strain sensors - Chapter 5: Tensile testing for design - Chapter 6: Tensile testing for determining sheet formability - Chapter 7: Tensile testing of metals and alloys - Chapter 8: Tensile testing of plastics - Chapter 9: Tensile testing of elastomers - Chapter 10: Tensile testing of ceramics and ceramic-matrix composites - Chapter 11: Tensile testing of fiber-reinforced composites - Chapter 12: Tensile testing of components - Chapter 13: Hot tensile testing - Chapter 14: Tensile testing at low temperatures - Chapter 15: High strain rate tensile testing - Glossary of terms - Reference tables - Index "

"Pemakaian material high tensile pada komponen otomotif semakin marak seiring dengan tuntutan cost reduction dalam dunia industri. Permasalahan mengenai besarnya tonnase proses dan sifat mampu bentuk material menjadi dasar dikembangkanya proses warm forming. Penelitian ini bertujuan untuk mendapatkan parameter optimal untuk proses warm forming sehingga bisa dihasilkan produk sesuai dengan standard komponen tanpa terjadinya kerusakan. Proses warm forming material SAPH 400 dengan variasi temperatur pre-heat menunjukkan bahwa besarnya pengurangan tonnase terbesar dihasilkan pada saat material dipanaskan pada temperatur pre-heat sebesar 600?C, dimana pengurangan tonnase proses mencapai 27% (4 Ton) dari tonnase cold forming (5,5 Ton). Semakin tinggi temperatur pre-heat, maka semakin mudah butiran dalam material terdeformasi, sehingga bentukan butir dari sample setelah dikenai proses warm forming menjadi pipih. Besarnya deformasi yang diterima oleh material membuat kerapatan antar butir meningkat serta menyebabkan pergerakan dislokasi akan terhambat, hal ini akan menyebabkan sample dengan variasi pre-heat sebesar 600?C mengalami kenaikan tensile strength sebesar 13% (menjadi 408 MPa dari 361 MPa), akan tetapi mengalami penurunan elongation sebesar 25% (menjadi 39,1% dari 52,4%). Penambahan air di cooling channel dalam dies menyebabkan kenaikan cooling rate menjadi 2 kali lipat menjadi 30?C/s, sehingga sample dengan media cooling menggunakan air yang mengalami kenaikan tensile strength sebesar 13% (menjadi 408 MPa dari 361 MPa). Sample yang dilakukan proses warm forming tanpa proses anil hanya mengalami kenaikan tensile strength sebesar 5%, karena material hanya mengalami proses tempering saja tanpa mengalami perubahan fasa, sehingga hal ini menyebabkan sample tanpa proses anil tetap susah ditingkatkan tensile strength-nya walaupun sudah dilakukan deformasi plastik dan proses cooling saat proses warm forming

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In the industral, high tensile materials used for automotive components generaly increase due to of the cost reduction requirement. Issues concerning the amount of tonnage process and formability of material becomes warm forming process of developing basic. This study aimed to obtain the optimal parameters for warm forming process so that products can be produced in accordance with standard components without damage. The warm forming process of SAPH 400 steel with a pre-heat temperature variation indicates that the magnitude of the largest tonnage reductions generated when the material is heated at 600?C of a pre-heat temperature, where the tonnage reduction reached 27% (4 Ton) from cold forming tonnage (5.5 Ton). The higher the preheat temperature, the more easily deformed grains in the material, so that the formation of grain samples after subjected to warm forming process becomes flat. The amount received by the material deformation made ??between grain density increases and causes the movement of dislocations is inhibited, this will cause the sample to the variation of preheat of 600?C tensile strength increased by 13% (from 361 MPa to 408 MPa), but the elongation decreased by 25% (to 39.1% from 52.4%). The addition of water in the cooling channels in the dies causes an increase in cooling rate become twice to 30 ?C/s, so the sample by using water cooling media that tensile strength increased by 13% (from 361 MPa to 408 MPa). Samples were subjected to warm forming process without annealing process is only increased tensile strength by 5%, because the material only experienced tempering process without phase transformation, so this causes the sample without annealing process remains difficult improved its tensile strength despite tight plastic deformation and cooling process when the warm forming process"

"Penggunaan polimer biodegradable sebagai matriks pada material komposit mulai dipertimbangkan untuk digunakan pada berbagai macam aplikasi karena memiliki sifat yang ramah lingkungan karena memiliki kemampuan yang dapat terdegradasi dengan baik dan cepat. Namun, polimer biodegradable memiliki beberapa kekurangan seperti sifat mekanisnya yang buruk. Metode yang dapat dilakukan untuk memperbaiki sifat mekanis dari polimer biodegradable ini adalah dengan menambahkan serat alami yang bertujuan sebagai penguat ke dalam matriks polimer sehingga membentuk material komposit. Untuk memperoleh produk dengan sifat mekanis yang sesuai dengan melakukan eksperimen secara langsung dibutuhkan proses yang panjang dan memakan biaya yang besar. Oleh karena itu, pembelajaran mesin hadir sebagai solusi dalam menciptakan proses pemilihan material yang efektif, akurat, singkat, dan hemat. Dalam penelitian ini, prediksi kekuatan tarik material polimer biodegradable berpenguat serat alami melibatkan empat model pembelajaran mesin dengan Extreme Gradient Boosting (XGB) sebagai model terpilih karena performanya yang stabil dan baik dengan metrik evaluasi skor R^2 sebesar 0,866, RMSE sebesar 7,26, dan MAE sebesar 4,84. Dilakukan proses validasi dengan melakukan perbandingan nilai yang model hasilkan dengan nilai aktual berdasarkan penelitian yang telah dilakukan terdahulu dan memperoleh performa yang baik dan optimum dengan selisih akurasi, yaitu rentang 1,02% sampai 27,19%.

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The use of biodegradable polymers as matrices in composite materials is starting to be considered for use in a wide variety of applications due to their environmentally friendly properties as they have the ability to degrade well and quickly. However, biodegradable polymers have some drawbacks such as poor mechanical properties. A possible method to improve the mechanical properties of these biodegradable polymers is to add natural fibers that act as reinforcement into the polymer matrix to form a composite material. Obtaining a product with suitable mechanical properties by conducting direct experiments is a lengthy and costly process. Therefore, machine learning comes as a solution in creating an effective, accurate, short, and economical material selection process. In this study, the tensile strength prediction of natural fiber-reinforced biodegradable polymer materials involves four machine learning models with Extreme Gradient Boosting (XGB) as the selected model due to its stable and good performance with the evaluation metrics of R^2 score of 0.866, RMSE of 7.26, and MAE of 4.84. The validation process was carried out by comparing the values generated by the model with the actual values based on previous research and obtained good and optimum performance with a difference in accuracy, which ranges from 1.02% to 27.19%."

"Recently, advanced technologies have put much attention on the materials selection as an alternative way to reduce the weight of material. Taking into account electronic devices, automobiles, aeronautics, and structural applications they are all required immense raw product. Magnesium and its alloys as one of the lightest metal (p = 1.8 g/m3) has attracted much intentions for an alternative metal alloy. Such good properties owned in magnesium including good castability, good machinability as well weldability and considerably cheap have made more convenient way for magnesium alloys to be used. However, its poor formability at room temperature is the major drawback of this material. Therefore, this project is intended to investigate the properties of AZ31 magnesium alloy especially for uniaxial tensile test at relatively low strain rate. Tensile properties were observed on the yield strength and elastic modulus which seems the crucial factor for magnesium tested at relatively low temperature. Slight dependency of plate orientations to the tensile properties for plate samples and tensile directions for sheet samples with three different sample thicknesses were also carried out. The experiment was done with the use of non-contact extensometer of Mini Instron Tensile Test.The main conclusion from the present study is that the thickness and the samples orientations affected tensile direction properties of the sheet samples. Microyielding occurred during the test which resulted in declining of modulus as the thickness increases. By contrast ultimate tensile strength, yield strength and ductility are generally increased as the thickness increased."

"ABSTRAKPada penelitian ini, nanokomposit matriks epoxy dengan kandungan organoclay yang berbeda telah disintesa dan pengaruh filler organoclay diamati. Uji tarik dan HDT dilakukan untuk mendapatkan sifat nanokomposit. Karakterisasi sifat mekanik, seperti tensile strength, tensile modulus, dan elongation at break diperoleh. Nanokomposit epoxy - clay telah disIntasa melalui proses polimerisasi insitu. Epoxy resin tipe DER 331 dan Versamid 125 digunakan masing-masing sebagai matriks dan curing agent. Nanofiller yang digunakan adalah organoclay yang dibuat dengan clay yang berasal dari Tapanuli melalui reaksi pertukaran kation pada kation ammonium yang terdapat pada surfaktan heksadesiltrimetilamonium bromida (HDTMABr) dengan metode ultrasonik. Struktur dari organoclay dan nanokomposit epoxy - clay dikarakterisasi dengan menggunakan XRD. Dari hasil XRD, basal spacing mineral clay akan mengembang dari 1.4 nm menjadi 2.2 nm. Sedangkan untuk epoxy - clay nanokomposit, tidak ada satupun hasil XRD yang memperlihatkan puncak difraksi. Puncak difraksi yang tidak terdeteksi dapat dihubungkan dengan struktur eksfoliasi atau basal spacing yang tinggi. Hasil uji tarik menunjukkan bahwa tensile modulus pada nanokomposit meningkat dengan bertambahnya kandungan clay. Peningkatan maksimum diperoleh ketika dilakukan penambahan 2 wt% kandungan clay, yaitu sebesar 8.24%. Tidak seperti halnya tensile modulus, penambahan clay pada nanokomposit menghasilkan tensile strength dan elongation at break yang lebih rendah dibandingkan dengan epoxy murni. Hasil dari uji Heat Deflection Temperature ( HDT) menunjukkan peningkatan suhu defleksi maksimum dicapai ketika penambahan kandungan clay sebesar 4 wt%.

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ABSTRACTIn this research, epoxy matrix nanocomposites with different compositions of organoclay are manufactured and effect of organoclay filler were studied. Tensile test and HDT were conducted to obtain the performance of nanocomposites. The mechanical characteristics, such as tensile strength, tensile modulus, and elongation at break were evaluated.

Epoxy - clay nanocomposites were synthesized by an in - situ polymerization process. Epoxy resin DER 331 and Versamid 125 were used as a matrix and a curing agent, respectively. Organoclay as nanofiller was prepared from Tapanuli clay with a cation exhange reaction using ammonium cations of hexadecyltrimethylammonium bromide (HDTMABr) surfactant by ultrasonic method. Both structure of organoclay and epoxy - clay nanocomposites were characterized using XRD.

From XRD results, it was exhibited that the basal spacing of clay minerals was expanded from 1.4 nm to 2.2 nm. While, none of epoxy - clay nanocomposites showed any diffraction peak. The absence of diffraction peaks can be attributed to exfoliated structure or higher basal spacing.

The tensile test results showed that the tensile modulus of the nanocomposites increases with increasing clay content. A maximum of 8.24% improvement is observed with an addition of 2 wt% clay. Unlike the tensile modulus, the nanocomposites of all clay content showed a lower tensile strength and elongation at break than that of the pure epoxy.

Heat Deflection Temperature (HDT) test exhibited that addition of 4 wt% clay provided a maximum of 10.45% improvement of temperature deflection."

"ABSTRAKNatural fiber reinforced polymer composites are widely developed because of their relative low price and eco-friendly. One of natural fiber sourches is pandanus tectorius leaf. This study aimed to determine the effect of variations in fiber volume fraction on tensile strength, impact strength, bending strength and morphological on sea pandanus fibers- polypropylene composites.Tensile test spesimen refer to ASTMD 638, impact test spesimen refes to ASTMD 5942-96, bending test spesimen refer to ASTMD 790 -02. The increasing of the volume fraction increased the tensile strength and impact strength. The tensile test results showed the highest tensile strength results for composites with a volume fraction of 35% was 25.82 MPa. The impact test results showed that the highest impact strength was obtained in the 35 % volume fraction of 0.0062 Joule/mm2. The bending test results showed that the highest bending strength was obtained in the 20% volume fraction of 24.96 MPa. Based on SEM test results, there were voids, cracks, fibers pull out on the composite."

"Latar Belakang: Karies atau gigi berlubang merupakan masalah gigi dan mulut yang sering terjadi pada manusia. Cara untuk menangani masalah tersebut yaitu dengan membuat restorasi. Bahan restorasi yang dapat digunakan untuk menangani karies adalah resin komposit. Salah satu resin komposit jenis supra-nano flowable yang beredar dipasaran Indonesia adalah Palfique Universal Flow (Tokuyama Corporation, Japan). Resin komposit supra-nano Palfique Universal Flow dapat digunakan sebagai restorasi direk untuk gigi anterior maupun posterior. Pada rongga mulut, saat dilakukannya curing, kecil kemungkinan light curing dapat berkontak langsung dengan permukaan restorasi terutama pada gigi posterior. Sejauh ini belum ada penelitian mengenai pengaruh jarak penyinaran terhadap diametral tensile strength pada resin komposit supra-nano Palfique Universal Flow. Tujuan: Menganalisis pengaruh jarak penyinaran terhadap diametral tensile strength dari resin komposit supra-nano Palfique Universal Flow tipe super low dan medium. Metode: Resin komposit yang digunakan adalah jenis supra-nano Palfique Universal Flow tipe super low dan medium. Spesimen resin komposit untuk menguji diametral tensile strength berbentuk silinder berdiameter 6 mm dan ketebalan 3 mm. Jumlah specimen berjumlah 36 dibagi masing-masing menjadi 3 kelompok pada tipe super low dan medium dengan jarak penyinaran 0, 3, dan 6 mm menggunakan light curing unit LED, dengan iradiansi 1050 W/cm2, durasi 10 detik. Nilai diametral tensile strength diuji dengan alat Universal Testing Machine. Data dianalisis dengan uji statistik One Way Anova dan uji Independent Sample T-test. Hasil: Nilai diametral tensile strength pada tipe super low (jarak penyinaran 0, 3, dan 6 mm secara berurutan) 46,47 ± 3,49 MPa, 43,78 ± 3,36 MPa, dan 40,00 ± 3,17 MPa. Nilai diametral tensile strength pada tipe medium (jarak penyinaran 0, 3, dan 6 mm secara berurutan) 49,19 ± 2,95 MPa, 45,64 ± 3,62 MPa, dan 43,36 ± 3,54 MPa. Nilai diametral tensile strength pada jarak 0 dan 6 mm pada tipe super low maupun medium memiliki perbedaan yang bermakna secara statistik (p<0,05). Nilai diametral tensile strength tipe medium lebih besar dibandingkan dengan tipe super low pada setiap kelompok jarak penyinaran tapi tidak memiliki perbedaan yang bermakna (p≥0,05). Kesimpulan: Semakin jauh jarak penyinaran pada resin komposit supra-nano Palfique Universal Flow tipe super low dan medium, maka nilai diametral tensile strength semakin rendah. Nilai diametral tensile strength resin komposit supra-nano Palfique Universal Flow tipe medium yang di-curing pada jarak penyinaran 0, 3, dan 6 mm lebih besar dibandingkan dengan tipe super low.

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Background: Tooth decay or dental caries is a common oral health issue in humans. One way to address this problem is by creating restorations. Composite resin is a restoration material commonly used to treat dental caries. One of the types of supra-nano flowable composite resins available in the Indonesian market is Palfique Universal Flow (Tokuyama Corporation, Japan). Supra-nano composite resin Palfique Universal Flow can be used for direct restorations in both anterior and posterior teeth. During the curing process in the oral cavity, there is a small chance that light curing can directly contact the restoration surface, especially in posterior teeth. So far, there has been no research on the influence of light curing distance on the diametral tensile strength of supra-nano composite resin Palfique Universal Flow. Objective: To analyze the effect of light curing distance on the diametral tensile strength of supra-nano composite resin Palfique Universal Flow in super low and medium types. Methods: The composite resin used was supra-nano Palfique Universal Flow in super low and medium types. Specimens for testing diametral tensile strength were cylindrical with a diameter of 6 mm and a thickness of 3 mm. There were 36 specimens, divided into 3 groups for each super low and medium types, with curing distances of 0, 3, and 6 mm using a LED light curing unit, with irradiance of 1050 W/cm2 for 10 seconds. Diametral tensile strength values were tested using a Universal Testing Machine. Data were analyzed using One-Way ANOVA and Independent Sample T-test. Results: Diametral tensile strength values for super low type (at curing distances of 0, 3, and 6 mm, respectively) were 46.47 ± 3.49 MPa, 43.78 ± 3.36 MPa, and 40.00 ± 3.17 MPa. Diametral tensile strength values for medium type (at curing distances of 0, 3, and 6 mm, respectively) were 49.19 ± 2.95 MPa, 45.64 ± 3.62 MPa, and 43.36 ± 3.54 MPa. There were statistically significant differences in diametral tensile strength values between 0 mm and 6 mm curing distances for both super low and medium types (p<0.05). The diametral tensile strength of the medium type was greater than that of the super low type in each curing distance group, but the difference was not statistically significant (p≥0.05). Conclusion: The farther the light curing distance in supra-nano composite resin Palfique Universal Flow super low and medium types, the lower the diametral tensile strength values. The diametral tensile strength values of supra-nano composite resin Palfique Universal Flow medium type cured at 0, 3, and 6 mm distances were greater than those of the super low type."

"ABSTRAKUntuk meningkatkan mutu beton, disamping komposisi semen, agregat kasar, agregat halus, dan faktor air semen, juga diperlukan bahan tambahan.Bahan tambahan ini bertujuan untuk mengubah satu atau lebih sifat-sifat beton sewaktu masih dalam keadaan segar atau setelah mengeras, misalnya mempercepat pengerasan, menambah encer adukan, menambah kuat tekan, menambah daktilitas, memperlambat terjadinya retak-retak.Salah satu bahan tambahan beton adalah fiber. Pemikiran dasar pemakaian fiber ini adalah menulangi beton dengan orientasi random, sehingga dapat mencegah terjadinya retak-retak pada beton yang terlalu dini, akibat panas hidrasi maupun akibat beban.Dengan dicegahnya retak-retak yang telalu dini, mengakibatkan kemampuan bahan untuk mendukung tegangan-tegangan yang terjadi akan semakin lebih besar.Bahan fiber ini ada beberapa jenis. Seperti baja, karbon, nilon, dan polypropylene. Sedangkan bentuknya, seperti oval, rektangular, bergantung pada proses pembuatan dan bahan mentahnya yang dipakai. Dalam penelitian ini dipakai dipakai polypropylene.Tujuan penelitian ini adalah untuk melihat pengaruh penambahan serat polypropylene terhadap kuat tekan, kuat tank talc langsung, kuat tank lentur, dan daya tahan abrasi pada beton.Hasil pengujian menunjukkan, bahwa dengan tambahan 0,1%-0,3% fiber, kuat tekan, kuat tarik tak langsung, kuat tarik lenturnya meningkat dan abrasinya menurun.

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ABSTRACTTo increase quality concrete, beside cement composition, coarse aggregate, fine aggregate, and water cement ratio, even if require admixtures.These admixtures to aim at change one or more properties concrete at still fresh or hardened, increase soft paste, increase compressive strength, increase ductility, delaying the growth of ckracks.One of admixtures for concrete are fibers. The basic idea use of fibers are the bones at concrete with ramdom orientate, until it can the restrain growth of very early ckracks at concrete, result both hydrated temperature and load. With the restrain growth of very ckracks, result in capability material to carry happened strength more bigger.Fiber material have some type. As steel, carbon, nylon, polypropylene. At the time shape, as oval, rectangular, hang by activation process, and the use of crude material. In this research the polypropyline will be used.The aim of this research is to find out the effect of the increase of Polypropylene fibers on concrete compressive strength, tensile strength, flexural strength, and abrasion.The test result show that by adding 0,1% - 0,3% fibers, compressive strength, tensile strength, flexural strength are mounting and abrasion is reduce."

"ABSTRAKBackground: Currently, there has been a lot of bulk fill resin, such as bulk fill giomer which has S-PRG filler particles and other bulk fill resin composites which have their own uniqueness. Polymerization with irradiance

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ABSTRACTLatar Belakang Saat ini telah banyak berkembang komposit resin bulk fill, seperti giomer bulk fill yang memiliki partikel filler S PRG serta komposit resin bulk fill lain yang memiliki keunikan tersendiri. Polimerisasi dengan LED irradiansi "