Delamination is a failure occured during hole-making processes in machining. This can affect to rejection of the product. This failure is commonly found when drilling low machinability of plastic-based materials such as thermoplastic composites. Therefore, to eliminate that phenomena, the materials are necessary to be reinforced. In this case, addition of the fiber can strengthen the composites. Besides, the way the fibers were arranged when composite manufacturing is also responsible to improve tensile strength of the composites. Improving tensile strength would also improve the shear strength of the material. Shear strength is normally adopted as indicator for machinability of materials. However, relation of shear strength improvement of composites due to fiber arrangement has been rarely discussed. Using orthogonal arrays L27 based on Taguchi, this study investigated the effect fiber arrangement on formation of delamination in drilling pine-apple leaves reinforced composites. The results highlighted that effect fiber arrangement was significant on formation of delamination at exit sides of drilled holes. Reduced rasio delamination had been identified at this side. This inferr that strengthening effect would be a good strategy in reducing delamination at the exit sides. KATA KUNCI delamination drilling pine-apple fiber arrangement KORESPONDENSI

Pada proses pemesinan, salah satu hal yang tidak bisa terlepaskan adalah timbulnya keausan pahat setelah dilakukan proses pemotongan. Untuk mengurangi laju keausan pahat biasanya dengan penentuan parameter pemotongan yang baik dan diberikan media pendingin yang berfungsi untuk mengontrol temperatur pada saat pelumasan pemotongan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh variasi parameter pemotongan dan pendinginan terhadap keausan pahat end mill HSS. Material benda kerja yang digunakan pada penelitian ini adalah aluminium sheet 1100 dan pahat end mill HSS berdiameter 6 mm dengan di variasikan parameter pemotongan yaitu gerak makan (30 mm/min, 40 mm/min, 50 mm/min), kedalaman potong (0,5 mm, 1 mm, 1,5 mm), media pendingin yang digunakan yaitu coolant, udara, oli. Pengambilan data keausan pahat dilakukan menggunakan mikroskop USB dengan cara mengukur panjang keausan tepi (VB). Berdasarkan Analisis for signal to noise ratios keausan pahat yang terkecil adalah pada parameter gerak makan 30 mm/min, kedalaman potong 0,5 mm, dan pendingin oli. Berdasarkan analisis of varian (ANOVA) parameter kedalaman potong dan media pendingin menghasilkan nilai P < 0,050, hal ini menunjukkan bahwa parameter tersebut merupakan faktor yang signifikan dalam mempengaruhi keausan pahat. Kata Kunci : keausan pahat, parameter pemotongan, media pendingin, end mill HSS, analisis for signal to noise ratios, analisis of varian (ANOVA).

This research was conducted to determine the effect of variations in activated charcoal media and temperature variations on the price of rockwell hardness and the chemical composition of ST 37 steel in the carburizing process. The carburizing process is widely used to increase hardness and add carbon to steel which has a low hardness value and needs to be given special treatment to increase the hardness of the steel. In this study, the carburizing media used were mangrove charcoal, coconut shell charcoal, lebanese wood charcoal that had been made into powder and a mixture of BaCO3 as a catalyst. In this study, the carburizing process was carried out with temperature variations, namely 750 o C, 850 o C and 900 o C after reaching the desired temperature and then held with a holding time of 2 hours. The percentage of carbon absorption is more absorbed in lebanese charcoal at a temperature of 900 o C with the addition of carbon by 0.61%. Whereas for rockwell hardness testing the highest hardness value at 900oC was found in lebanese charcoal with a hardness value of 79.9 HRC.

In the machining process, one of the things that cannot be released is the occurrence of burr formation or chip that sticks to the moment after the deduction process is carried out. To reduce burr formation is usually by determining good cutting parameters and given a cooling medium that functions to control the temperature during lubrication.This study aims to determine the burr formation on the 1100 aluminum sheet material using the machining method of milling raouter with the depth of feeding in accordance with the thickness of the workpiece. The spindle rotation used is 1200 rpm with a variation of the cutting tool eyes that is 4 mm, 6 mm, and 8 mm of the HSS tool brand and variations of the cooler namely air, coolant, oil. This research uses taguchi and ANOVA methods by measuring burr formation using USB microscope with 1200 x magnification. Then get the smallest burr formation value of 0.16819 mm with the parameter arrangement of the diameter of the drill bit 6, (f) 40 mm / minute, oil coolant. As for the Exit (outlet) the smallest burr formation of 0.27211 mm in the arrangement of the diameter of the tool diameter of the 4, (f) 50 mm / minute oil cooler.