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"ABSTRAKFarilr adalah Salah safn kegaga/an malarial yang disebabkan oleh bcban bernlang (dinamis). Kcgagalan faiik yang .sering mnncul selama pengoperasian par!pesawar (Thbe & Brackei dari Manybld Cooling Air Drrbine Case ofPrari & Wlwirney Engine Type J T9D - 7Q nnruk pesawal Boeing B74 7 - 200) ada/ah pada daerah lavan.Pengelasan yang digunakan nnlnk perbaikan, dapai menyebabkan pernbahan mi/frostruklur dan sU`al - sifa! mekanis pari, seria rneryadi renian lerhadap iegangan sisa. Dengan menerapkan melode perlalcuan panas annealing dan sho! peening pada hasil pengelasan diharapkan umurfatil: par! yang menggunakan bajh lahan kara! AISI 34 7 dapar dilingkafkan.Penelilian ini mengunakan maierial :gi plale dengan kerebalan 1,8 mm sebanyal: 2 buah nnink masing - masing perlaknan Peilaknan pertama hasi/pengelasan, lredna periakuan panas annealing hasil pengelasan, dan keliga perlalcnan panas annealing dan sho! peening hasil pengelasan, Pengelasan yang dilalcnkan unrnk semua perlakr.-an menggnnalcan merode GTAW (Gas Ynngsren Arc Welding) dengan arns 83 anrpere. Untnk perlalman kedna dan keiiga, material :ni dipanaslcan sampai Iemperatnr annealing 1050 OC diiahan selama 3 rneni! 30 deiilc kemndian didingin/can di dalam dapnr sampai lemperalnr /camar. Perlaknan ketiga selarnntnya dilalmkan proses sho! peening _nada permukaan material :ji dengan inlensiias 2 siklus per 60 delill. P?Hg?Ul0l1fGlfklflll(lk semna perlalman menggnnakan mode pembebanan bending dengan legangan sebesar 90% dari iegangan luluh logam indn/r. Dafa falik yang diambil adalah jnmlah sililns, fora makro dan mikro perpafahan.Hasil penelitian mernngukkan bahwa perlalcnan panas annealing hasil pengelasan (perialman kedua) memberilfan siklus yang Iebih banyak. Sedangkan perlaknan panas annealing dan shot peening hasil pengelasan (perlalaian lceliga) dihasilkan siklns yang lebih rendah. Dari fenomena lersebn! dapa! disimpnlkan bahwa peningkaran umur funk terhadap baja iahan kara! AISI 347 yang lelah mengalami pengelasan lerjadi pada perlalman kedua.

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"ABSTRAKFatik inerupakan salah saiu fakmr icegagalan akibar reiak (crack) yang rimbul dari adanya silclus iegangan pada maierial terienlu. Kegagalan ini selalu diawali pada permukaannya dan ie/jadi lceiika regangannya beraafa di bawah legangan lululi material iersebur. Falik memegang peranan penling dalam apiikasi perancangan indusiri terulama pada komponen-komponen yang sering rnenerima pembebanan lzverzilang Ulucfuaiing l0aaD, sehingga material dapat mengalami lrerusalcan.Kompanen Low Pressure Turbine Cooling i\/lanifold General Eleciric Aircraj? Engine CF6-50C dalam pesawal McDonnel Douglas DCI 0-30 yang ierbuat dari material baja rahan karat AISI 347 sering mengalami crack yang berawal di daerah lasan saat operasi berlangsung Berdasarkan referensi di lapangan, prosedur repair unlulc penanggulangan crack pada lcomponen iersebut adalah non deslruclive ies: spar FP] (Fluaresceni Peneirani lnslaectionj dan welliing. Akibatnya malriks austeni! tilialc culcup kuat untulc mendukung lzasil lasan sehingga kelangguhan sambungan lasan berlcurang lcetika lingkungan mengalami sikl us geraran dan ier/nal.Perlalcuan panas-stress relieving dan perlakaan panas stress relieving plus sho! peening ililakukan lerhadap material baja tahan karat AISI 347 laasil las GTAW zinruk melilial pengarulmya Ierhaclap urnur fatik. Pada penelilian ini pengujian faiilc clengan metode bending dilakukan pada dua buah sample uniulc musing-masing perlakaan rerseb ui. Unruk mempercepai iijormasi da/a nmurjarik yang clilzasilkan aicibar perlakuan yang cliberikan, malca digunakan pernbebanan 90% dari lcelcuatan luluh material.Hasil penelilian menunjiilfkan balrwa pada kondisi perlakuan panas-stress relieving dan perlaka/an panas stress relieving plus sho! peening ma/erial baja ialian karat AISI 347 memiliki lcecenclerungan zimur fafik yang lebilz cepal clibanflingkan malerial yang lzanya mengalaini proses pengelasan."

"Komponen otomotif seperti pegas daun dalam pengoperasiannya mengalami beban dinamis yang besarnya tergantung pada kondisi jalan. Salah satu metoda agar pegas daun tidak mengalami penurunan umur yang terlalu besar, adalah dengan memberikan proses shot peering sehingga terbentuk tegangan sisa tekan pada pegas daun tersebut. Dalam makalah ini diberikan hasil penelitian variasi kecepatan tembakan peluru shot peening terhadap benda uji dari baja pegas 16 MnCr5 yang telah mengalami proses perlakuan panas pengerasan. Jenis pengujian yang dilakukan meliputi : uji kekerasan, kekasaran permukaan dan uji tekuk dinamis. Dari hasil pengujian diketahui bahwa shot peening pada umumnya dapat menaikkan kekuatan material menahan beban dinamis. Akan tetapi bila kecepatan tembakan peluru shot peening terlalu tinggi, maka dapat menyebabkan kerusakan pada permukaan benda uji, sehingga dapat menurunkan kekuatan material menerima beban dinamis.

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Automotive components like leaf spring when in operation is always subjected to dynamic loading. The magnitude of load depends on road condition. One method to extend leaf spring life time is obtained by shot peening process to produce compressive residual stress. This paper presents the results of the speed variation of shot bullets to leaf spring steel 16 MnCr 5 which have been heat treated by hardening process. Several tests were performed including hardness test, surface roughness test and dynamic bending fatigue test. The test results show that shot peening improved fatigue strength, but when the speed of the bullets were too high it could damaged the surface of the specimen, and eventually reduced fatigue strength."

"[ABSTRAKPada proses pembentukan logam metode die casting, nitridisasi memegangperanan penting dalam peningkatan umur pakai dies. Inovasi proses perlakuanpermukaan yang dilakukan sebelum nitridisasi bertujuan untuk meningkatkan efisiensi nitridisasi dan kedalaman lapisan nitrida pada baja H13 Modifikasi.Nitridisasi gas dilakukan dalam vacuum furnace, pada suhu 510oC selama 5 jam.Shot peening dilakukan dengan menggunakan bola baja dengan tekanan 461 kPa.Shot blasting dilakukan sebagai metode pembersihan permukaan material menggunakan partikel SiC. Karakterisasi permukaan sampel sebelum dan sesudahvariasi proses difokuskan pada perubahan struktur mikro, distribusi kekerasanmikro, dan komposisi kimia lapisan nitridisasi. Dari proses nitridisasi yangdidahului shot peening, didapatkan kekerasan maksimal 1196 HV dengan kedalaman efektif lapisan difusi 72 !m. Nilai ini lebih besar dari proses nitridisasitanpa didahului perlakuan permukaan, yang menghasilkan kekerasan maksimal 1101,4 HV dengan kedalaman efektif lapisan difusi 54!!m. Variasi proses nitridisasi dengan shot peening menghasilkan ketebalan white layer 4,1!!m; lebih tebal dari proses nitridisasi tanpa shot peening 3,7!!m. Sedangkan pada nitridisasiyang tidak didahului perlakuan permukaan tidak ditemukan adanya white layer.ABSTRAKIn the die casting practice, nitriding represents an important factor in enhancingthe service life of dies. Surface treatment innovation prior to nitriding in thisresearch aim to increased the nitriding efficiency and the depth of nitrided layer ofH13 Modification steel. The gas nitriding process was performed at temperature510oC for 5 hours in a vacuum furnace. Shot peening was performed prior tonitriding using a cast steel ball with 461 kPa nozzle pressure. Shot blasting withSiC particle was also performed as a surface cleaning method. Characterizationson the surface of steel were done before and after the variation of nitriding processwith focused on the microstructure, microhardness profile, and the chemicalcomposition of the nitrided layer formed. It was found that shot peening prior tonitriding significantly increased the nitriding kinetics, that results in 1196 HVmaximum surface hardness with 72 !m effective case depth. This results werehigher than the nitriding process without prior surface preparation, which haveonly 1101,4 HV maximum surface hardness with 54!!m effective case depth.While the nitrided only process did not formed a white layer, the shot peenedsample was found to have a white layer with 3,7!!m thick., In the die casting practice, nitriding represents an important factor in enhancingthe service life of dies. Surface treatment innovation prior to nitriding in thisresearch aim to increased the nitriding efficiency and the depth of nitrided layer ofH13 Modification steel. The gas nitriding process was performed at temperature510oC for 5 hours in a vacuum furnace. Shot peening was performed prior tonitriding using a cast steel ball with 461 kPa nozzle pressure. Shot blasting withSiC particle was also performed as a surface cleaning method. Characterizationson the surface of steel were done before and after the variation of nitriding processwith focused on the microstructure, microhardness profile, and the chemicalcomposition of the nitrided layer formed. It was found that shot peening prior tonitriding significantly increased the nitriding kinetics, that results in 1196 HVmaximum surface hardness with 72 !m effective case depth. This results werehigher than the nitriding process without prior surface preparation, which haveonly 1101,4 HV maximum surface hardness with 54!!m effective case depth.While the nitrided only process did not formed a white layer, the shot peenedsample was found to have a white layer with 3,7!!m thick.]"

"Karakterisasi soldering pada die casting mengharuskan cetakan memiliki ketahanan erosi dan juga bebas dari kegetasan white layer pada nitriding. Penggabungan Shot peening dan nitriding adalah proses perlakuan pada permukaan yang biasa digunakan untuk meningkatkan kekuatan untuk komponen struktural maupun mekanis Pada penelitian ini material H13 pebanding yaitu H13 Premium dan H13 Superior yang masing masing dilakukan 5 variasi proses perlakuan permukaan dan 2 variasi waktu tahan pada proses nitriding kemudian dicelup ke dalam lelehan alumunium ADC12 pada temperatur 680°C dan di tahan selama 30 detik, 5 menit, dan 30 menit. Karakterisasi permukaan baja difokuskan pada struktur mikro, distribusi kekerasan, komposisi kimia, kekasaran permukaan, dan kehilangan berat dari baja perkakas H13. Hasilya didapat H13 modifikasi menunjukkan kekerasan hingga 1416 HV serta selisih ketebalan lapisan compound dan broken layer pada soldering yaitu 13.35 μm dan 73.14 μm dibandingkan dengan shot peening saja. Pada penelitian ini menunjukkan bahwa variasi shot peening sebelum dan sesudah nitriding menghasilkan ketahanan soldering yang lebih baik.

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Soldering characteristic on die casting makes it's should be has high wearability erotion and also realeased from white layer embrittlement on nitriding process. Both of shot peening and nitriding are kind of process which can increasing surface strength characterization in structural or mechanical components and also as an effective way to prevent soldering. In this case research, H13 tool steel will be compared with supreme and superior which each part of materal has 5 combination surface treatment and 2 kind of holding time of nitriding. Then dipped into the molten of ADC12 Alumnium at temperature 680°C and held for 30 second, 5 minutes and 30 minutes.

Characterizations on the surface of the steel were focused on the microstructure, microhardness profile, chemical composition, surface roughness, and weight loss of the H13 tool steel. Result found that H13 modification show hardness until 1416 HV and diffence thickness compound and broken layer on soldering 13.35 μm and 73.14 μm compare with only shot peening treatment. This research result showed that best resistance to soldering create from combination shot peening before and after nitriding."

"Optimalisasi paduan cartridge brass sebelumnya telah dilakukan lewat penambahan paduan Al, menghasilkan paduan Al-brass dengan fasa α dan β biner yang memiliki kekuatan mekanis lebih tinggi dari paduan konvensional tanpa mengalami reduksi elongasi yang signifikan. Dalam penelitian ini, dipelajari mengenai pengaruh proses manufaktur canai dingin dan perlakuan anil terhadap karakteristik fasa dan yang terdapat dalam paduan Cu-29.5Zn-2.5Al wt. hasil pengecoran gravitasi. Pelat as-cast dihomogenisasi pada temperatur 800 °C selama 2 jam, dideformasi menggunakan canai dingin dengan derajat deformasi sebesar 20, 40, dan 50, dan diberikan perlakuan anil pada temperatur 150, 300, 400, dan 600 °C selama 30 menit. Karakterisasi dilakukan melalui observasi mikrostruktur dengan mikroskop optik, pengambilan gambar dengan SEM, uji komposisi OES dan SEM-EDS, karakterisasi fasa dengan XRD, dan pengujian kekerasan mikro dengan metode Vickers. Paduan as-homogenized memiliki struktur mikro martensitik dua fasa α dan βdan dengan diamond-shape configuration. Setelah canai dingin terlihat adanya mekanisme deformasi slip, cross-slip, twinning, dan pembentukan shear band hanya pada fasa ?, sementara peningkatan kekerasan mikro terjadi pada kedua fasa dan. Selanjutnya, perlakuan anil temperatur rendah pada 150 °C menghasilkan peningkatan kekerasan mikro paduan akibat pembentukan atmosfir Cottrel, sementara perlakuan anil di temperatur 300, 400, dan 600 °C menghasilkan penurunan nilai kekerasan mikro akibat mekanisme penguraian dislokasi dan relaksasi tegangan. Rekristalisasi butir equiaxed hanya terjadi di fasa α dan β pada hasil anil temperatur 600 °C.

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Previous research displayed a successful attempt in optimizing mechanical properties of cartridge brass by utilizing Al alloying element, producing binary Al brass alloy with higher strength and hardness without a significant diminution in its elongation compared to conventional cartridge brass alloys. Hereinafter, the effect of cold rolling and annealing treatment on the characteristics of α and β phases in gravity casted Cu 29.5Zn 2.5Al wt. alloy was studied. Produced as cast samples were homogenized at 800 °C for 2 h, subjected to cold rolling with 20, 40, and 50 reduction in thickness, and annealed at 150, 300, 400, and 600 °C for 30 min. Phase characterizations were done through optical microscopy, SEM imaging, OES and SEM EDS composition analysis, XRD, and micro Vickers hardness measurement. A binary martensitic morphology with diamond shape configuration compromising of α and β phases were found in as homogenized sample. Cold rolling resulted in slip, cross slip, twinning, and formation of shear band, solely in the phase. However, increase in microhardness was detected in both α and β phases. Furthermore, it was found that low temperature annealing at 150 °C resulted in an increase of micro hardness of both phases due to the formation of Cottrel atmosphere, while usual decrease in hardness value was discovered after annealing at 300, 400, and 600 °C through disl°Cation entanglement and stress recovery mechanisms. Recrystallized phase β grains in equiaxed shape were visible in sample annealed at 600 °C."

"Purpose of Research (specific objective and/or statement of hypothesis in around 300 to400 words. Please try to avoid using an additional page). Zry-4 is an alloy of Ziconium (Zr) with alloying elements of Fe,Cr, and Sn with weight percentage of 0.2%, 0.07% and 1.5% respectively. This alloying element addition is intended to improve the mechanical properties as well as Zirconium, that is corrosive resistance at high temperature. Besides the alloying elements, the micro structural morphology of Zry-4, as results of thermomechanic treatment process, also an active role to determine mechanical, physical and corrosion properties. This alloy is used as structure and cladding materials for Pressurized water Reactor (PWR) nuclear fuel element. Zirconium alloy of Zr-702 will also be used for chemical engineering devices due to its high corrosion resistance in acid and alkali liquid as well as at high temperature. Examples of device are : Distillation Column, Reactor, Pump Housing and Heat exchanger and Heating coil due to mechanical properties at high temperature. Some researchs have been done previously to observe changes of mechanical and corrosive properties of Zry-4 with solution treatment 0-phase, but unfortunately they are not continued between deformation degree and grain size with new precipitate is obtained.In this research we plan to carry out a cold deformation process of 0-quenching result and be continued with annealing process. From the process results we will observe the morphology of micro structure of Zry-4. This process will enable to determine the deformation level, time and temperature annealing to obtain a certain microstructure according to the desired mechanical properties (Microhardness). Results of research can hopefully be used as input in the working process of Zry-4.Optical Microscopy, Transmission Electron Microscopy and X-Ray Diffraction will be used in the microstructure observation."

"Aluminium merupakan logam kedua terbanyak yang digunakan setelah baja. Salah satu aluminium yang banyak digunakan di bidang industri adalah paduan aluminium seri 6xxx, dimana unsur utama dalam paduan ini adalah Mg dan Si. Paduan Al-Mg-Si dapat ditingkatkan sifat mekaniknya melalui proses deformasi dan perlakuan panas. Penelitian ini bertujuan untuk mengetahui pengaruh persen deformasi dan temperatur anil terhadap rekristalisasi dan sifat mekanik paduan Al-1,06Mg-0,63Si (% berat).Pembuatan paduan menggunakan metode squeeze casting. Proses homogenisasi dilakukan pada temperatur 400 oC selama 4 jam. Kemudian paduan diberi perlakuan canai dingin dengan variasi persen deformasi sebesar 5, 10 dan 20 %. Pada sampel deformasi 20 % diberi perlakuan anil dengan variasi 400, 475 dan 550 oC selama 1 jam diikuti pencelupan cepat dengan media air. Karakterisasi material yang dilakukan meliputi pengujian komposisi kimia, pengujian kekerasan mikro dan makro, pengamatan struktur mikro yang terdiri dari mikroskop optik dan Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) dan pengujian X-Ray Diffraction (XRD).Hasil penelitian menunjukkan bahwa terjadinya pemipihan butir seiring dengan meningkatnya persen deformasi yang diberikan. Deformasi 5, 10 dan 20 % menghasilkan rasio deformasi sebesar 1,16, 1,56 dan 2,07 secara berurutan dan meningkatkan kekerasan mikro dan makro paduan. Nilai kekerasan tertingi pada sampel deformasi 20 % dengan kekerasan mikro sebesar 49,71 VHN dan kekerasan makro sebesar 62 HRE. Perlakuan anil pada temperatur 400 dan 475 oC menyebabkan terjadinya mekanisme rekristalisasi dimana telah tumbuh butir baru yang bebas dislokasi sehingga terjadi penurunan kekerasan mikro dan makro paduan. Pada temperatur 500 oC terjadi mekanisme pertumbuhan butir yang menyebabkan terjadinya penurunan nilai kekerasan mikro dan makro dari 35,94 VHN menjadi 33,85 VHN dan 48,50 HRE menjadi 47 HRE.

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Aluminium is the second most widely used metal after steel. One of them is the 6xxx series aluminum alloy, whose Mg and Si as the main elements. Mechanical properties of Al-Mg-Si can be improved through deformation processes and heat treatment. The annealing treatment after deformation will restore the alloy's ductility through recovery, recrystallization, and grain growth mechanisms. This study aimed to determine the effect of percent deformation and annealing temperature on recrystallization and mechanical properties of Al-1.06Mg-0.63Si alloy (wt. %).

The alloy was produced by squeeze casting method. The homogenization process was carried out at 400 oC for 4 hours followed by cold rolling with different deformation of 5, 10, and 20 %. The 20 % deformed samples were annealed at 400, 475 and 550 oC for 1 hour, followed by water quenching. The material characterization included chemical composition testing, micro hardness and macro hardness, and observation of microstructures by an optical microscope and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) and X-Ray Diffraction (XRD) testing.

The results showed that higher deformation led to more elongated grains. Deformation of 5, 10, and 20 % resulted in a grain L/d ratio of 1.16, 1.56, and 2.07, respectively, as well as an increase in microand macro hardness. The highest hardness value was observed in the 20 % deformation sample with a micro hardness of 49.71 VHN and a macro hardness of 62 HRE. The annealing treatment at 400 and 475 oC caused a recrystallization mechanism where new grains that were free of dislocations had grown, resulting in a decrease in the micro and macro hardness of the alloy. At the temperature of 500 oC, the grain growth mechanism occured, which caused a decrease in the micro and macro hardness value from 35.94 VHN to 33.85 VHN and 48.50 HRE to 47 HRE."