Uji Performansi Cutting Fluid Pada Proses Pemesinan Drilling Plat Baja

Cutting fluid is a very important component in the process of machining (metal-cutting operation), in addition to extend tool life cutting fluid in some cases able to reduce cutting force and refine the product surface machining results.Machining conditions used in this study are machined dry (do not use cutting fluid) and by using cutting fluid dromus and synthetic oil. Workpiece material used as test specimens in this reserches is a steel JIS G3106 SM490YA. And for material of cutting tool used is made of High Speed Steel (HSS).To know the performance of the cutting fluid can be known from measurements such as tool wear generated. Tool wear measurement is done by use spindle speed 2500 rpm and perform ingestion 150 times for each tools and variable. Also, provide load 150 kg on drilling machine handle. From the testing will be known cutting fluid which has the best performance. Good performancecutting fluid is can decrease the friction between the cutting tool with the workpiece so that hasthe smallest tool wear generated so that it can extend cutting tool lifeCutting fluid is a very important component in the process of machining (metal-cutting operation), in addition to extend tool life cutting fluid in some cases able to reduce cutting force and refine the product surface machining results.Machining conditions used in this study are machined dry (do not use cutting fluid) and by using cutting fluid dromus and synthetic oil. Workpiece material used as test specimens in this reserches is a steel JIS G3106 SM490YA. And for material of cutting tool used is made of High Speed Steel (HSS).To know the performance of the cutting fluid can be known from measurements such as tool wear generated. Tool wear measurement is done by use spindle speed 2500 rpm and perform ingestion 150 times for each tools and variable. Also, provide load 150 kg on drilling machine handle. From the testing will be known cutting fluid which has the best performance. Good performancecutting fluid is can decrease the friction between the cutting tool with the workpiece so that hasthe smallest tool wear generated so that it can extend cutting tool life

Analisa Kekuatan dan Tegangan pada Sambungan Rel-54 Hasil Pengelasan Thermite dengan Metode Elemen Hingga

The train is one mode of land transportation that is widely used by people of Indonesia. Safety and convenience are the factors that users wanted in transportation. The number of train accidents are often caused by conditions of the trains railway which tend to be safe. One of the causes of railway accidents is the condition of rail welded joints that have been cracked. There are several methods used rail connections, including connections with connector plates, electric arc welding joint press, and the connection using thermite welding. In writing this report the author will take the discussion of thermite welding. Thermite welding is used only in the long rails. The result of this welding can be classified of 3 (three) areas namely: base metal, weld metal and heat affecting zone. In this study, the maximum stress that works on Haz metal and weld metal due to the imposition of the wheel locomotive D 300, CC 202 and CC 203 will be calculated by computational. Some parameters used in the simulation of static loading rail-54 using Finite Element Method (FEM) with ANSYS APDL include Yield Strength (σy), Modulus of Elasticity (E) and Poisson's Ratio (υ). The parameters used are the result of tensile test results of material rail-54 thermite welding, with Rail-54 test sample obtained from the PT. Dwi Tunggal Karya that has welding certificate issued by BKI (Bureau of Classification Indonesia). The result showed that the von misses stress (σeq) on the weld metal at a maximum of 361.638 MPa while value of material yield strength (σy) is 552.8211 MPa and the von misses stress (σeq) on the areas haz metal maximum of 445.877 MPa while the value of material yield stress / yield strength (σy) is 542.2 MPa. So in theory if the von misses σeq <σy then concluded that the local weld metal and HAZ metal is still in a safe condition. Security level of material weld metal and HAZ metal in the rail 54 can also be classified as save because it has ≥ 0.5 margin of safety

Optimasi Parameter Proses Bubut Pada Berbagai Jenis Baja Dengan Media Pendingin Cooled Air Jet Cooling

Proses bubut merupakan proses permesinan yang digunakan untuk melakukan produksi khususnya untuk pemotongan berbagai jenis logam. Untuk meningkatkan produktivitas, maka dilakukan proses permesinan yang efisien yaitu dengan mengoptimalkan parameter-parameter proses pembubutan saat melakukan pemotongan pada beberapa jenis material logam. Beberapa parameter yang mempengaruhi proses bubut, antara lain putaran spindle, laju pemakanan dan kedalaman potong. Sampai saat ini media pendingin yang sering digunakan masih mengandung zat-zat yang berbahaya bagi kesehatan dan tidak ramah lingkungan. Salah satu solusi yang diterapkan saat ini adalah penggunaan media pendingin udara berkecepatan tinggi yang didinginkan (cooled air jet cooling). Tujuan dari penelitian ini adalah untuk menemukan kondisi parameter permesinan yang paling optimal untuk mendapatkan hasil terbaik dari kekasaran permukaan, temperatur pahat, dan konsumsi daya listrik mesin dari proses bubut baja St 40, St 60 dan stainless steel 304. Metode penelitian yang digunakan adalah secara eksperimental dan dianalisa menggunakan metode taguchi. Dari hasil penelitian diperoleh kesimpulan bahwa untuk menghasilkan kekasaran permukaan yang halus diperoleh pada kondisi parameter putaran spindle 850 rpm, laju pemakanan 0.125 mm/rev, kedalaman potong 1 mm dan jenis material stainless steel 304. Temperatur pahat yang paling rendah diperoleh pada kondisi parameter putaran spindle 580 rpm, laju pemakanan 0.125 mm/rev, kedalaman potong 0.25 mm dan jenis material St 40. Dan konsumsi daya listrik mesin bubut paling rendah diperoleh pada kondisi parameter putaran spindle 580 rpm, laju pemakanan 0.125 mm/rev, kedalaman potong 0.25 mm dan jenis material stainless steel 304

Effect of Using Coolant on the Formation of Microcracks, Burr and Delamination in Bone Drilling Process

Direct approach for bone fracture treatment usually involves restoring the fractured parts to their initial position and immobilizing them with plates, screws and wires. This approach needs a bone surgery drilling to produce hole for screw insertion. But this drilling process causes mechanical damages, i.e microcracks, burr formation and delamination, that can reduce the stability of the fixation. One of the ways to minimize it is by using coolant. Moreover, it is noted that bone has anisotropic microstucture. The object of this study is to understand the effect of coolant on mechanical damages that occur in bone drilling and to understand the effect of microstructure difference on microcracks that occur in the drilled walls holes. Adult bovine bones and adult goat bones were used in this study as the specimens to represent differences in cortical bone microstructure. Five consecutive holes from the distal to the proximal in each specimen were generated using manual hand-drill (spindle speed (n) = 1000 rpm; drill bit (d) = 4 mm diameter) with the use of coolant as variation. The drilling holes then stained and observed using a microscope. As the result, it was found that the use of coolant can significantly reduce the drilling temperature. Microcracks, burr formation and delamination were found to be quite large in the drilling holes without coolant. However, there is no microcrack found in the drilling holes with coolant, there is only a small number of burr formation was found. In addition, it was found that the differences in bone microstructure affect the number and length of microcracks that occur in the wall of the hole. It can be concluded from this study that the application of coolant is very effective to reduce the drilling temperature and enhancing the quality of the hole generated by bone drilling and the higher the density of osteon in cortical bone, the easier the microcrack to initiate and propagate

Optimalisasi Besarnya Sudut Potong Pahat pada Proses Roughing Aisi 1040 Menggunakan Metode Elemen Hingga

Proses pemesinan dengan gaya pemotongan yang kecil akan menurunkan pemakaian daya listrik, meningkatkan kualitas produk dan menurunkan laju keausan pahat. Salah satu cara yang dilakukan untuk menurunkan gaya pemotongan adalah dengan mengoptimasi besarnya sudut potong pahat. Selama proses roughing gaya pemotongan relatif tinggi, dan umumnya menggunakan sudut potong pahat negatif. Pada makalah ini dibahas pengaruh besarnya sudut potong pahat negatif pada proses bubut tehadap gaya pemotongan, dengan tujuan untuk mengetahui besarnya sudut potong pahat yang paling optimal. Metode penelitian dilakukan dengan pemodelan menggunakan sofware Finite Element Method (FEM) dan material yang digunakan adalah baja AISI 1040. Simulasi dilakukan pada sudut potong -15° sampai 0°. Hasil dari simulasi kemudian dibandingkan dengan hasil empirik berdasarkan pendekatan dari Kienzle dan hasil eksperimental oleh Günay, M., dkk (2005). Dari penelitian ini diperoleh kesimpulan bahwa gaya pemotongan akan menurun sebanding dengan pergerakan sudut potong pahat dari -15⁰ sampai 0⁰, sedangkan perbedaan hasil simulasi FEM dengan hasil empirik adalah 12,94% dan dengan hasil eksperimen adalah 16,10%. Kata kunci: sudut potong pahat, gaya pemotongan, FEM, roughing, bubut