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ABSTRAK
Penelitian ini mempersembahkan sebuah metode untuk menentukan persinggungan antara cutter dan benda kerja (PCB) pada permesinan permukaan kompleks di milling 5-sumbu. PCB sesaat didefinisikan dengan menentukan dua titik persinggungan, titik persinggungan terendah (PR) dan titik persinggungan tertinggi (PT). Titik PR dihitung menggunakan metode yang disebut metode grazing. Sementara titik PT dihitung menggunakan kombinasi dari metode discrit dan analitik. Pada milling kasar dan semi finishing, bentuk permukaan benda kerja direpresentasikan dengan vektor vertikal. Metode yang disebut Toroidal?boundary digunakan untuk mencari titik PT ketika ia beradadi pahat pada sisi toroidal. Di sisi lain, metode yang disebut Cylindrical-boundary digunakan untuk menghitung titik PT untuk flat cutter dan sisi silinder dari toroidal cutter. Untuk benda kerja dengan permukaan bebas, sebuah metode hibrid, kombinasi dari metode analitik dan diskrit, digunakan. Semua model PCB yang diusulkan pada studi ini diverifikasi dan hasilnya membuktikan bahwa metode yang diusulkan adalah akurat. Efisiensi metode yang dikembangkan juga dibandingkan dengan metode Z-mapping. Hasilnya mengkonfirmasi bahwa model yang diusulkan lebih efisien dalam hal waktu komputasi. Model PCB telah diterapkan untuk mendukung metode untuk memprediksi gaya pemotongan. Hasil pengujian menunjukan bahwa gaya pemotongan yang diprediksi memiliki hasil yang mendekati dengan gaya pemotongan yang diukur dari ekperimen.

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ABSTRAK
This study presents a simple method to define the Cutter Workpiece Engagement (CWE) during sculptured surface machining in five-axis milling. The instantaneous CWE was defined by determining two engagement points, lowermost engagement (LE)-point and uppermost engagement (UE)-point. LE-point was calculated using a method called grazing method. Meanwhile the UE-point was calculated using a combination of discretization and analytical method. During rough milling and semi-finish milling, the workpiece surface was represented by vertical vector. The method called Toroidal?boundary was employed to obtain the UE-point when it was located on cutting tool at toroidal side. On the other hand, the method called Cylindrical-boundary was used to calculate the UE-point for flat-end cutter and cylindrical side of toroidal cutter. For a free-form workpiece surface, a hybrid method, which is a combination of analytical method and discrete method, was used. All the CWE models proposed in this study were verified and the results proved that the proposed method were accurate. The efficiency of the proposed model in generating CWE was also compared with Z-mapping method. The result confirmed that the proposed model was more efficient in term of computational time. The CWE model was also applied for supporting the method to predict cutting forces. The test results showed that the predicted cutting force has a good agreement with the cutting force generated from the experimental work.

Abstrak :
ABSTRAK
Keberhasilan sebuah proses manufaktur dapat diindikasikan dari kualitas produk yang dihasilkan. Pada micro-blanking, kualitas produk ditunjukkan dengan kualitas permukaan geser (shear surface). Sedangkan pada bending, sudut springback menjadi menjadi indikator kualitas dari produk yang dihasilkan. Oleh karena itu, untuk meningkatkan kualitas produk hasil proses micro-forming, diperlukan pengembangan pada aspek-aspek sistem micro-forming. Namun, tingkat kesulitan yang cukup tinggi pada proses fabrikasi micro-forming tool menuntut kesederhanaan disain dan kemudahan pemilihan komponen standar. Selain itu, karakteristik material yang berubah karena adanya size effect menyebabkan respon material pun berubah, sehingga memerlukan perlakuan khusus sebelum material diproses. Oleh sebab itu, masih diperlukan pengembangan pada aspek lain yang diharapkan dapat meningkatkan kualitas produk yang dihasilkan. Aspek tersebut adalah parameter proses yang terdiri dari kecepatan punch, pelumasan dan holding time. Pada penelitian ini dilakukan pengembangan melalui penerapan peningkatan kecepatan punch dan holding time untuk meningkatkan kualitas produk hasil micro-forming. Variasi kecepatan punch yang digunakan adalah 0,5mm/s sampai dengan 10mm/s untuk blanking dan 0,5mm/s sampai dengan 15mm/s untuk bending. Holding time hanya diterapkan pada bending dengan variasi antara 2 detik sampai dengan 11 detik. Material yang digunakan sebagai spesimen adalah aluminium, kuningan, tembaga dan SUS304 dengan kisaran ketebalan 0,1mm. Hasil pengujian proses blanking menunjukkan bahwa dengan diterapkannya kecepatan punch yang berbeda, terjadi perubahan geometri shear surface. Rasio shear zone yang merupakan indikator kualitas dari part yang dihasilkan melalui proses blanking meningkat dengan semakin tingginya kecepatan punch. Demikian pula halnya dengan burr zone yang merupakan indikator visual termudah untuk dilihat, dipengaruhi pula oleh kecepatan punch. Pada arah rolling tertentu, rasio burr zone menurun dengan diterapkannya kecepatan punch yang lebih tinggi. Dalam hal proses bending, Hasil pengujian menemukan bahwa penekukan material aluminium, tembaga, SUS304 sebaiknya menggunakan arah rolling transversal, yaitu arah rolling tegak lurus terhadap sumbu tekukan. Karena sudut springback yang dihasilkan lebih kecil daripada material dengan arah rolling longitudinal. Selain daripada itu, holding time sangat baik diterapkan sebagai metode koreksi springback pada material tembaga dengan arah rolling transversal.

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ABSTRACT
The success of a manufacturing process can be indicated by the quality of the product produced. In micro-blanking, product quality is indicated by the quality of the shear surface. While at bending, springback angle becomes an indicator of the quality of the product produced. Therefore, to improve product quality as a result of the micro-forming process, it is necessary to develop aspects of the micro-forming system. However, a high degree of difficulty in the fabrication process of micro-forming tools requires simplicity of design and ease of selection of standard components. Besides, the characteristics of the material that changes due to the size effect cause the material response to change, requiring special treatment before the material is processed. Therefore, development is still needed in other aspects that are expected to improve the quality of the products produced. This aspect is a process parameter consisting of punch speed, lubrication and holding time. In this study, development was carried out through the application of increased punch and holding time to improve the quality of products produced from micro-forming. The variation in punch speed used is 0.5mm/s up to 10mm/s for blanking and 0.5mm/s up to 15mm/s for bending. Holding time is only applied to bending with variations between 2 seconds to 11 seconds. The materials used as specimens are aluminum, brass, copper, and SUS304 with a thickness range of 0.1mm. The results of the blanking process investigation show that by applying different punch speeds, changes in the shear surface geometry occur. The shear zone ratio which is an indicator of the quality of the blanked-product increases with the higher punch speed. Similarly with burr zone, which is the most natural visual indicator to see, is also influenced by punch speed. In specific rolling directions, the burr zone ratio decreases with the application of higher punch speeds. Concerning the bending process, the test results found that bending of aluminum, copper, SUS304 material should implement the transverse rolling direction, i.e., the direction of rolling perpendicular to the bending axis. Because the springback angle produced is smaller than the material with a longitudinal rolling direction. Apart from that, holding time is very well applied as a springback correction method on copper material with a transverse rolling direction.

Abstrak :
Pemantauan keausan pahat pada proses pemesinan merupakan hal yang penting. Perambatan keausan pahat yang tidak normal maupun peristiwa rusaknya pahat sebelum masa pakai dapat mempengaruhi hasil pemesinan. Pada pemesinan micro-milling, keausan pahat terjadi jauh lebih cepat dibandingkan pada pemesinan macro-milling dikarenakan efek downsizing terhadap geometri pahat itu sendiri. Untuk hal tersebut, sebuah sistem pemantauan keausan pahat dapat memberikan informasi perambatan keausan pahat agar pengguna dapat mengantisipasi kejadian-kejadian yang destruktif serta dapat mengambil keputusan lebih lanjut atas proses pemesinan yang sedang berlangsung. Pada kerja penelitian ini telah dikembangkan sebuah sistem pemantauan keausan pahat untuk pemesinan micro-milling berbasis teknologi digital twin. Sistem yang dikembangkan mampu memberikan informasi estimasi keausan pahat serta informasi ketidakpastian estimasi itu sendiri dengan memanfaatkan simulasi real-time yang dijalankan dalam digital twin. Model virtual dikembangkan berdasarkan model mekanistik dari proses micro-milling yang merupakan bagian dari pendekatan berbasis hukum fisika (physics-based). Model virtual yang dikembangkan meliputi model motor spindle, model unit pengendali (controller) spindle, dan model torsi potong. Ketika simulasi digital twin berjalan, model virtual mensimulasikan variabel-variabel yang terkait proses pemesinan micro-milling serta berinteraksi dengan beberapa variabel lain yang diperbarui (di-update) berdasarkan data real-time sensor-sensor di mesin micro-milling. Variabel tersimulasi digital twin dijadikan informasi dasar untuk dibandingkan dengan variabel yang didapat secara real-time, khususnya variabel torsi motor spindle yang kemudian ditransformasi ke ruang keausan pahat. Extended Kalman filter (EKF) digunakan sebagai salah kerangka kerja untuk mengintegrasi informasi tersimulasi dan informasi real-time untuk menghasilkan sebuah estimasi keausan pahat. Proses pemantauan keausan pahat dilakukan dengan menggunakan diagram kendali (control chart) dan kategorisasi tingkat keausan pahat untuk mengevaluasi nilai estimasi keausan pahat dan ketidakpastian estimasi itu sendiri. Eksperimen pemesinan slot micro-milling dilakukan untuk benda kerja yang terbuat dari stainless steel SUS304 dengan menggunakan pahat mikro berbahan karbida berukuran diameter 1000 µm. Dengan menggunakan empat dataset yang dihasilkan dari eksperimen, sistem pemantauan yang dikembangkan mampu menunjukkan proses perambatan keausan pahat dengan rata-rata error estimasi terbesar adalah 0.052 mm dan nilai ketidakpastian estimasi σtruth terbesar adalah ±0.04 mm untuk dua mata pahat. Untuk implementasi menggunakan EKF, rata-rata error estimasi terbesar adalah 0.038 mm dengan standar deviasi terbesar adalah ±0.031 mm untuk dua mata pahat. Kerja penelitian ini juga telah menghasilkan sebuah alat pengukur keausan pahat yang disebut MicroEye dengan metode observasi langsung (direct observation) menggunakan kamera mikroskop dan lengan robot aktif 6-DOF (degree of freedom). Dalam hal kemampuan pengambilan gambar, MicroEye mampu membawa kamera ke posisi yang ditargetkan sehingga seluruh area keausan pahat yang ingin dideteksi berada dalam ROI (region of interest) dengan tingkat keberhasilan sebesar 86.66%. Dalam hal kemampuan mencapai posisi, MicroEye memiliki error posisi sudut maksimum sebesar 0.596◦ dan error posisi linear maksimum 0.0336 cm pada arah sumbu x dan 0.767 cm pada arah sumbu y. ......Tool wear monitoring is an essential aspect of the machining process. The tool breakage and the abnormality of tool wear progression affect the machining result. Due to the downsized tool’s geometry, the progression of tool wear in micro-milling is much faster than in macro-milling. A tool wear monitoring system helps to give information about the progression of tool wear so that the user can anticipate unwanted destructive events and make further decisions for the ongoing machining process. This dissertation presents the development of a tool wear monitoring system based on the digital twin technology for micro-milling applications. The developed system can provide the tool wear estimate and the estimation uncertainty altogether by running the real-time digital twin simulation. The virtual model was developed from the mechanistic model of the micro-milling process, which is part of a physics-based approach. The virtual model consists of the spindle motor, spindle controller, and cutting torque models. During the simulation, the virtual model simulates the variables of the micro-milling process and interacts with some of the real-time variables coming from the sensors in the micro-milling machine. The simulated variables (such as spindle motor torque) as the ground information are compared to the real-time variables in the wear space. Extended Kalman filter (EKF) is used as the framework to integrate the simulated and real-time information to estimate the wear growth. Then, the wear estimate and the estimation uncertainty are evaluated using a control chart and a categorization of wear level. The slot micro-milling experiment was conducted for SUS304 stainless steel workpiece with 1000 µm carbide micro-tool. The developed system can monitor the progression of tool wear with the largest mean of estimation error = 0.052 mm and the largest estimation uncertainty = ±0.04 mm. The implementation of EKF framework has improved the estimation accuracy with largest estimation error 0.038 mm with largest standard deviation ±0.031 mm for two cutting teeth. This dissertation also presents the result of a tool wear measurement device called MicroEye. The device uses a direct observation approach with a microscope camera as the primary sensor. The device has an active 6-DOF (degree of freedom) arm robot mechanism for motion flexibility. In terms of wear analysis, MicroEye can provide three metrics to analyze the difference between the fresh and the worn tools. In the aspect of image acquisition, MicroEye was able to bring the camera to the targeted position with the success rate 86.66% so that the ROI (region of interest) of the tool image is fully captured by the camera. In positioning, MicroEye achieved a maximum error of angular position 0.596◦, the maximum error of linear position 0.0336 cm in x-axis direction and 0.767 cm in y-axis direction.

Abstrak :
[ABSTRAK
Proses micro-milling merupakan salah satu pilihan proses mikro-manufaktur 3D, yang mampu menghasilkan produk dengan bentuk kompleks. Bentuk kompleks umumnya ditemui pada mold dan dies atau produk kompleks lainnya seperti impeller dan turbin. Tahapan penelitian diawali dengan pengembangan mesin micro-milling Hadia Micromill-5X, yang meliputi pengembangan konstruksi, pengembangan sistem kontrol gerak dan pengembangan metode perencanaan lintasan pahat yang memanfaatkan sistem CAD/CAM terintegrasi. Tahap berikutnya adalah karakterisasi perfoma proses micro-milling dalam menghasilkan produk mikro, yang dilakukan melalui studi literatur dan pengujian eksperimental. Analisis karakterisasi meliputi kekasaran permukaan, burr yang terbentuk, serta analisis kondisi pahat pada rentang waktu tertentu. Hasil karakterisasi menunjukkan kekasaran permukaan pada sisi proses end-milling dapat dicapai lebih baik bila dibandingkan pada sisi proses peripheral dengan nilai kekasaran permukaan minimum 20 nm. Terdapat empat jenis burr yang terbentuk pada suatu micro-channel yaitu yaitu enterance burr, top burr, exit side burr dan bottom burr. Bottom burr merupakan salah satu jenis burr baru yang diidentifikasi pada penelitian ini. Hasil utama dari tahap ini adalah rekomendasi parameter pemesinan optimum untuk aplikasi produk mikro dengan bentuk dinding tipis. Dari hasil pengujian performa, mesin Hadia Micromill-5X dan metode yang dikembangkan terbukti mampu menghasilkan produk dinding tipis datar dengan ketebalan minimum 11,71 μm dengan aspek rasio 23,48. Perbedaan antara tebal desain dan tebal aktual (∆Tda) adalah berkisar antara 3,51 μm hingga 25,48 μm. Salah satu penyebabnya perbedaan ini adalah ketidaksesuaian diameter pahat aktual (Da) dengan diameter yang ditetapkan. Ketika ketidaksesuaian pahat turut diperhitungakan terhadap diameter aktual, maka deviasi atau perbedaan ukuran yang terjadi (∆Tae) adalah berkisar antara -4,69 μm hingga 3,48 μm. Nilai ∆Tae masih berada dalam rentang keakurasian motor stage, yaitu ± 5 μm maupun run-out aktual, yaitu 8,33 μm. Metode micro-milling untuk produk dinding tipis dengan bentuk kompleks yang dikembangkan pada penelitian ini, diaplikasikan untuk pembuatan 2 micro-impeller yang masing-masing memiliki jumlah blade dan ketebalan yang berbeda. Micro-impeller yang memiliki 8 blade dengan diameter aktual 3.098 μm, tinggi 600 μm, ketebalan rata-rata blade 33,7 μm dan jarak terluar antara blade 1.207 μm, deviasi ukuran maksimum yang terjadi hingga 13,3 μm dapat dihasilkan dengan baik. Namun, pada micro-impeller yang memiliki 16 blade dengan diameter 3.190 μm dan ketebalan rata-rata blade 11,96 μm terdapat beberapa blade yang terbelah dan terdefleksi. Secara umum, metode micro-milling yang dikembangkan telah dapat diaplikasikan dengan baik. Keterbatasan dalam menghasilkan bentuk dinding tipis lebih dikarenakan sifat dan karakteristik material dari produk, yang mengalami defleksi sebagai akibat dimensi dinding yang sangat tipis.;

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ABSTRACT
Micro-milling process is one of choices to manufacture 3D product, which has the ability to produce complex shape. Complex shapes are commonly found in mold and dies or other complex product such as impeller and turbine. The research was started by developing the micro-milling machine, Hadia Micromill-5X, which covers the development of machine construction, control system and tool-path generation method by using integrated CAD/CAM system. The next part of the research is to characterize the micro-milling performance to produce micro product, through literature study and experimental test. Characterizations analysis covers surface roughness, burrs and tool condition in a certain range of time. The result shows that the surface roughness on end-milling process side is better than peripheral process side, with minimum surface roughness of 20 nm. There are four types of burr that formed on micro-channel, which are entrances burr, top burr, exit side burr and bottom burr. Bottom burr is the first identify in this research. The main result of characterization phase is a recommendation of optimum cutting parameter for thin-wall micro-product application. Based on performance testing, the micro-milling machine Hadia Micromill-5X and developed method is proved to have the capability to produce thin-wall product with minimum thickness of 11.71 μm, with an aspect ratio of 23.48. The difference between design and actual thickness (∆Tda) is around 3.51 μm to 25.48 μm. One of the causes of the difference is the incompatibility of actual tool diameter (Da) with desired diameter. If the tool diameter incompatibility is considered, than the size differences (∆Tae) are around -4.69 μm to 3.48 μm. ∆Tae value is still in the range of motor stage accuracy and actual run-out, which ± 5 μm are and 8.33 μm respectively. Micro-milling method for thin-wall complex shape product developed in this research was applied to produce 2 micro-impellers with different amount of blades and thickness. 8?s blade micro-impeller with actual diameter of 3,098 μm, 600 μm heights, average thickness of 33.7 μm, with 13.3 μm of maximum deviation size, was produced properly. However, there are several torn and cloven blades on 16?blade micro-impeller with a diameter of 3,190 μm and average actual thickness of 11.96 μm. In general, the micro-milling method developed in this research is properly applied. The limitation to produce a thinner wall is caused by the material properties and characteristic of the product, which experiences deflection due to the flimsiness of a thin wall. ;Micro-milling process is one of choices to manufacture 3D product, which has the ability to produce complex shape. Complex shapes are commonly found in mold and dies or other complex product such as impeller and turbine. The research was started by developing the micro-milling machine, Hadia Micromill-5X, which covers the development of machine construction, control system and tool-path generation method by using integrated CAD/CAM system. The next part of the research is to characterize the micro-milling performance to produce micro product, through literature study and experimental test. Characterizations analysis covers surface roughness, burrs and tool condition in a certain range of time. The result shows that the surface roughness on end-milling process side is better than peripheral process side, with minimum surface roughness of 20 nm. There are four types of burr that formed on micro-channel, which are entrances burr, top burr, exit side burr and bottom burr. Bottom burr is the first identify in this research. The main result of characterization phase is a recommendation of optimum cutting parameter for thin-wall micro-product application. Based on performance testing, the micro-milling machine Hadia Micromill-5X and developed method is proved to have the capability to produce thin-wall product with minimum thickness of 11.71 μm, with an aspect ratio of 23.48. The difference between design and actual thickness (∆Tda) is around 3.51 μm to 25.48 μm. One of the causes of the difference is the incompatibility of actual tool diameter (Da) with desired diameter. If the tool diameter incompatibility is considered, than the size differences (∆Tae) are around -4.69 μm to 3.48 μm. ∆Tae value is still in the range of motor stage accuracy and actual run-out, which ± 5 μm are and 8.33 μm respectively. Micro-milling method for thin-wall complex shape product developed in this research was applied to produce 2 micro-impellers with different amount of blades and thickness. 8?s blade micro-impeller with actual diameter of 3,098 μm, 600 μm heights, average thickness of 33.7 μm, with 13.3 μm of maximum deviation size, was produced properly. However, there are several torn and cloven blades on 16?blade micro-impeller with a diameter of 3,190 μm and average actual thickness of 11.96 μm. In general, the micro-milling method developed in this research is properly applied. The limitation to produce a thinner wall is caused by the material properties and characteristic of the product, which experiences deflection due to the flimsiness of a thin wall. , Micro-milling process is one of choices to manufacture 3D product, which has the ability to produce complex shape. Complex shapes are commonly found in mold and dies or other complex product such as impeller and turbine. The research was started by developing the micro-milling machine, Hadia Micromill-5X, which covers the development of machine construction, control system and tool-path generation method by using integrated CAD/CAM system. The next part of the research is to characterize the micro-milling performance to produce micro product, through literature study and experimental test. Characterizations analysis covers surface roughness, burrs and tool condition in a certain range of time. The result shows that the surface roughness on end-milling process side is better than peripheral process side, with minimum surface roughness of 20 nm. There are four types of burr that formed on micro-channel, which are entrances burr, top burr, exit side burr and bottom burr. Bottom burr is the first identify in this research. The main result of characterization phase is a recommendation of optimum cutting parameter for thin-wall micro-product application. Based on performance testing, the micro-milling machine Hadia Micromill-5X and developed method is proved to have the capability to produce thin-wall product with minimum thickness of 11.71 μm, with an aspect ratio of 23.48. The difference between design and actual thickness (∆Tda) is around 3.51 μm to 25.48 μm. One of the causes of the difference is the incompatibility of actual tool diameter (Da) with desired diameter. If the tool diameter incompatibility is considered, than the size differences (∆Tae) are around -4.69 μm to 3.48 μm. ∆Tae value is still in the range of motor stage accuracy and actual run-out, which ± 5 μm are and 8.33 μm respectively. Micro-milling method for thin-wall complex shape product developed in this research was applied to produce 2 micro-impellers with different amount of blades and thickness. 8’s blade micro-impeller with actual diameter of 3,098 μm, 600 μm heights, average thickness of 33.7 μm, with 13.3 μm of maximum deviation size, was produced properly. However, there are several torn and cloven blades on 16’blade micro-impeller with a diameter of 3,190 μm and average actual thickness of 11.96 μm. In general, the micro-milling method developed in this research is properly applied. The limitation to produce a thinner wall is caused by the material properties and characteristic of the product, which experiences deflection due to the flimsiness of a thin wall. ]

Abstrak :
[ABSTRAK
Teknologi Friction stir welding (FSW) menjadi alternatif proses penyambungan aluminium yang relatif sederhana, bahkan dalam beberapa hal memiliki kelebihan jika dibanding dengan cara konvensional (misalnya: proses las, proses keling dsb.). Proses FSW memerlukan mesin perkakas yang memiliki kekakuan terhadap gaya (aksial dan transversal) dan ketelitian gerak yang baik, agar mampu menahan gaya reaksi dalam proses FSW. Proses FSW untuk material lunak dan tipis tidak membutuhkan mesin perkakas yang kokoh, bahkan bisa menggunakan mesin freis (milling machine) atau mesin gurdi (drilling machine) dengan mengganti pahat (tools) dan parameter proses FSW yang sesuai. Kebutuhan struktur ringan pada industri transportasi menjadi topik penelitian utama, dengan tujuan mengurangi berat struktur, tetapi tidak mengurangi kekuatan dan kualitas struktur. Kebutuhan informasi teknologi FSW untuk penyambungan plat tipis dan konstruksi ringan sangat dibutuhkan di industri. Proses penyambungan plat aluminium tipis (tebal < 1mm) dan untuk membatasi kerusakan akibat gaya dan panas berlebihan, membutuhkan teknologi dan peralatan khusus. Tujuan penelitian ini adalah mengembangkan proses micro Friction Stir Welding (μFSW) dan meneliti hubungan parameter μFSW terhadap kualitas hasil las, dan mencari parameter optimum menggunakan metode Neural Network (NN) dan Genetic Algorithm (GA), serta pembuatan simulasi temperatur μFSW. Pada penelitian disertasi ini akan terbagi menjadi dua bagian yaitu, yang pertama adalah uji eksperimental dan pembuatan model matematik. Pada bagian kedua adalah penelitian aplikasi proses micro Friction Stir Welding pada pembuatan struktur ringan. Diharapkan dengan penelitian disertasi ini akan; 1) mengetahui efek parameterparameter pengelasan terhadap respon dan kualitas pada micro Friction Stir Welding, dan 2) memberikan usulan metode pemilihan parameter yang optimum. Penelitian berhasil mendapatkan parameter proses μFSSW pada aluminium A1100 yang menghasilkan temperatur las lebih dari 460 oC (yaitu 0,8.Tm, Melting Temperature), merupakan batas temperatur minimal untuk menghasilkan kualitas sambungan las yang baik. Uji kualitas las dibuktikan dengan hasil uji mekanik dan struktur mikro. Parameter proses ini telah diterapkan pada proses penyambungan aluminium tipis untuk pembuatan struktur ringan honeycomb.

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ABSTRACT
Friction Stir Welding is a relatively new technique for joining metal. In some cases on aluminum joining, FSW gives better results compared with the arc welding processes, including the quality of welds and produces less distortion. Research on friction stir welding has been done, but data results are difficult to obtain by manufacturing engineers/workshop, unlike other process parameter data, for example: Milling process data, Turning process data, grinding process data. The ultimate goal of this research is to build a model and simulation process of micro Friction Stir Welding (μFSW), which is main parameters, the force that occurs, the quality of results and the mechanical properties of FSW welds. Research will investigate the relationship between different parameters in FSW aluminum A1100, 0.4 mm thickness. The goal is to develop a mathematical model that establishes the relationship between multiple input and multiple outputs. As part of this research, will be investigated material changes in temperature, forces, torque and tool wear as a function of output parameters and explore their interactions. Experimental design (DoE) will be used and data analysis using Neural network Methodology and Genetic Algorithm. Research found the optimum μFSSW parameters, which is weld temperature higher than 460 oC (mean 0,8.Tm, Melting Temperature). The welds qualities were measurred by shear load test, micro structure test, micro hardness test, and composition test. The optimum μFSSW parameters were applied to build the light structure honeycomb., Friction Stir Welding is a relatively new technique for joining metal. In some cases on aluminum joining, FSW gives better results compared with the arc welding processes, including the quality of welds and produces less distortion. Research on friction stir welding has been done, but data results are difficult to obtain by manufacturing engineers/workshop, unlike other process parameter data, for example: Milling process data, Turning process data, grinding process data. The ultimate goal of this research is to build a model and simulation process of micro Friction Stir Welding (μFSW), which is main parameters, the force that occurs, the quality of results and the mechanical properties of FSW welds. Research will investigate the relationship between different parameters in FSW aluminum A1100, 0.4 mm thickness. The goal is to develop a mathematical model that establishes the relationship between multiple input and multiple outputs. As part of this research, will be investigated material changes in temperature, forces, torque and tool wear as a function of output parameters and explore their interactions. Experimental design (DoE) will be used and data analysis using Neural network Methodology and Genetic Algorithm.. Research found the optimum μFSSW parameters, which is weld temperature higher than 460 oC (mean 0,8.Tm, Melting Temperature). The welds qualities were measurred by shear load test, micro structure test, micro hardness test, and composition test. The optimum μFSSW parameters were applied to build the light structure honeycomb.]

Abstrak :
ABSTRAK
Perkembangan mesin milling dari 3-axis menjadi 5-axis pada umumnya bertujuan meningkatkan kualitas hasil pemesinan, mempercepat waktu total pengerjaan, mengurangi biaya pemesinan dan memperpanjang umur pahat. Namun pada kenyataanya terdapat keterbatasan untuk proses pemesinan awal milling 5-axis, khususnya untuk bentuk-bentuk tertentu. Dengan metode yang umum digunakan hingga saat ini, proses pemesinan awal untuk permukaan yang terdapat area close bounded volume CBV tidak dapat dilakukan proses pemesinan tanpa merubah orientasi pahat. Dalam upaya meningkatkan efektifitas proses pemesinan awal, maka pengembangan metode pemesinan pada area CBV perlu dilakukan. Tahapan dalam pengembangan metode pemesinan awal ini dimulai dari menentukan klasifikasi area CBV pada permukaan benda kerja, menentukan initial orientasi pahat pada area CBV selanjutnya memastikan seluruh CC point bebas collision dan gouging serta terakhir adalah pembuatan lintasan pahat dari seluruh cutter contact point CC point untuk proses pemesinan awal. Setelah di simulasikan untuk beberapa model, terbukti bahwa metode yang dikembangkan dapat meningkatkan volume pemesinan awal yang memberi dampak efektifitas pemesinan awal meningkat.

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ABSTRACT
Technological development of manufacturing industry comes hand in hand with the increase of workpiece quality that can be applied on machining process. Particularly, the Roughing process on 5-axis milling by using a general method on CAM software gives many limitations. Complex models and Impeller Blade are the examples; these models cannot necessarily be applied on machining process. By conducting a CBV evaluation of an area for which a roughing process can be used, a tool path can be formed with a consideration of tool-path length. It can be done by using a point cloud as a cutter contact CC point. Tool orientations can be calculated based on a vector operation from a CC point in a CBV area to the nearest and highest CC point outside the CBV area. From each tool orientation at the formed CC point, it is still possible that interference occurs due to changing the orientation of the tools, thus detection of interference and tool interference avoidance can be applied using rotation and translation method until tools and workpiece surface are free from interference. From each CC point already free from interference, then it is simulated and tested against the rough machining process using a 5-axis milling machine. Out of the simulation results on 4 model shapes, the increased of rough machining volume may be achieved, thus, the effectiveness of the 5-axis milling machining process with the developed method is increasing.

Abstrak :
Untuk mencapai proses efisiensi milling, salah satunya dengan menggunakan strategi pemesinan peripheral milling karena material removal rate (mrr) yang besar terutama bila diaplikasi pada permukaan planar. Peripheral milling menemukan banyak kendala saat mengerjakan jenis permukaan sculptured dan memerlukan bentuk tool khusus yang menyesuaikan bentuk permukaan. Selain itu upaya efisiensi dapat dilakukan dengan mengurangi setup tool pada setiap tahapan proses (single setup tool) dengan menggunakan parameter tool yang sama misalnya silindrical cutter. Namun peripheral milling menggunakan tool silinder pada permukaan sculptured memerlukan metode dan strategi khusus, karena akan menemukan banyak interference antara tool dengan permukaan tergantung pada parameter tool dan initial tool orientation-nya. Sehingga problem dalam menentukan metode dan strategi pemesinan peripheral milling pada sculptured surface menggunakan tool silinder menjadi menarik untuk diteliti lebih lanjut dan menjadi keterbaharuan dalam penelitian ini. Posisi tool pada setiap cc-point mengandung nilai Normal vector (N), Feed direction vector (F) dan Tool Vector (T). Penetilian ini menghasilkan mengembangkan metode inisial orientasi tool peripheral, metode pendeteksian dan penghindaran interference peripheral, metode inisialisasi area non-machinable peripheral, dan pengembangan strategi diantaranya startegi tool orientasi alternative peripheral, strategi penghindaran intereference, startegi milling area non-machinable peripheral, strategi efektifitas terhadap arah pemakanan, strategi end milling sebagai solusi milling area non-machinable dan terakhir startegi hybrid milling (gabungan peripheral dengan end milling) menggunakan single parameter tool. Hasil pengembangan metode dan strategi kemudian divalidasi dengan simulasi milling pada model uji sculptured surface. Setelah diaplikasi pada beberapa model uji sculptured surface berbasis model faset, membuktikan metode dan strategi pemesinan yang dikembangkan telah berhasil disimulasikan pada seluruh area sculptured surface. Hasilnya dipresentasikan dalam prosentase kemampuan peripheral milling dan hasil akhir berupa toolpath simulasi hybrid milling. Hasil pengembangannya pada metode dan startegi peripheral milling ini dapat dijadikan sebagai acuan pengembangan strategi milling 5-axis selanjutnya ......To achieve the milling efficiency process, one of them is by using a peripheral milling machining strategy because high of the material removal rate (mrr), especially when applied to a planar surface. Peripheral milling encountered many obstacles when working on sculptured surface types and required a special form of tool to adjust the surface shape. In addition, efficiency efforts can be made by reducing the setup tool at each stage of the process (single setup tool) by using the same tool parameters such as a cylindrical cutter. However, peripheral milling using the tool cylinder on the sculptured surface requires a special method and strategy, because it will find a lot of interference between the tool and the surface depending on the tool parameters and the initial tool orientation. So that the problem in determining the method and strategy of peripheral milling machining on sculptured surfaces using tool cylinders becomes interesting for further research and becomes a novelty in this study. Tool position at each cc-point contains Normal vector (N), Feed direction vector (F) and Tool Vector (T) values. This research resulted in developing initial peripheral tool orientation methods, detection and avoidance methods for peripheral interference, methods for identification non-machinable peripheral areas, and developing strategies including alternative orientation tool peripheral strategies, interference avoidance strategies, non-machinable peripheral area milling strategies, effectiveness strategies for feed direction, end milling strategy as a solution for milling non-machinable areas and finally hybrid milling strategy (combination of peripherals and end milling) using a single parameter tool. The results of developing methods and strategies were then validated by simulating milling on the sculptured surface test model. After being applied to several sculptured surface test models based on the faceted model, it was proven that the developed machining methods and strategies has been simulated successfully on the entire sculptured surface area. The results are presented in the percentage of peripheral milling capabilities and the final result is a hybrid milling simulation toolpath. The results of its development on this peripheral milling method and strategy can be used as a reference for the development of the next 5-axis milling strategy.