KARAKTERISASI MATERIAL REFRAKTORI BASA BERBAHAN DASAR MAGNESIA (MgO) DENGAN VARIASI SINTERING 1200oC, 1300oC, DAN 1400oC GUNA LINING TUNGKU INDUKSI PENGECORAN BAJA PT SUYUTI SIDO MAJU CEPER KLATEN

Refractory is one type of ceramic that has ability to maintain its condition both physically and chemically and very stable at high temperature conditions. Refractory are used as insulation lining the furnace in metal smelting. However, most of the metal casting industry, particularly in Indonesia in the purchase of refractory materials based on a manual book submitted by the manufacturer of refractory without knows the properties and characteristics of refractory materials. This is caused by the lack of knowledge of refractory materials. This refractory material characterization study aims to determine the shape and grain size by meshing, the chemical composition refractory compounds with X-RD (X-Ray Diffraction), and the density and porosity of the refractory which are the physical properties of refractory. Refractory material in this research is consists of large and small aggregate that is used for induction furnace steel making PT Suyuti Sido Maju Ceper, Klaten. These materials are formed with a pressure of 240 MPa with mold dimensions are 17,8 mm diameter and 50 mm in height. The process of making the specimen through sintering process with variation of temperature at 12000C, 13000C, and 14000C and holding time 2 hours at maximum temperature. Heating rate for sintering this material is 100C/min and cooling rate of 200C/min. The results of refractory characterization is for a large aggregate refractory material has a grain size greater than 0,150 mm while the grain size for small aggregates are smaller than 0,150 mm. The grain shape for this refractory is rounded and well-rounded.. The chemical composition of the main constituent of refractory material is magnesia (MgO) with weight fraction ~ 95%. Density values for refractory magnesia (MgO) at a temperature of 12000C, 13000C and 14000C are 3,04 g/cm3, 3,08 g/cm3 and 3,11 g/cm3. And theoretically, the density values for magnesia (MgO) is 3,58 g/cm3. While the value of porosity for refractory magnesia (MgO) studied by 15,7%, 12,4% and 9,2% for the sintering temperature of 12000C, 13000C and 14000C. This shows that with increasing sintering temperature will affect the increase in density and lower porosity of the refractory material

Pengembangan media belajar PAI interaktif berbasis Macromedia Flash di Kelas XI SMK Kartika 1 Surabaya

Media pembelajaran PAI adalah salah satu alat bantu dalam kegiatan belajar mengajar. Selain untuk mempermudah penyampaian materi, media pembelajaran PAI juga berfungsi untuk menambah durasi ingatan siswa terhadap materi-materi PAI. Media pembelajaran yang baik seharusnya memenuhi beberapa kriteria pemilihan media pembejaran yang baik, salah satunya menarik minat siswa dan bersifat interaktif. Akan tetapi, hasil penelitian di lapangan menunjukkan bahwa media yang digunakan dalam proses pembelajaran kurang menarik minat siswa dan hanya bersifat komunikasi satu arah. Oleh karena itu, perlu dilakukan suatu penelitian pengembangan media pembelaajran PAI yang tujuannya menemukan prinsip-prinsip pengembangan media pembelajaran, dan mewujudkannya dalam proses menciptakan media pembelajaran PAI yang lebih menarik minat siswa dan bersifat interaktif serta memenuhi kriteria pemilihan media pembelajaran yang baik. Metode yang digunakan dalam penelitian ini adalah Penelitian dan pengembangan (Research and development). Lokasi penelitian di SMK Kartika 1 Surabaya, subyeknya adalah guru dan siswa kelas XI di SMK Kartika 1 Surabaya. teknik pengumpulan datanya menggunakan lembar validasi dan angket. Teknik analisis data menggunakan prosentase dan analisis item pernyataan. Analisis data akan dijadikan bahan pertimbangan dalam merevisi prduk agar lebih memenuhi kriteria pemilihan media pembelajaran yang baik. Hasil dari penelitian ini menunjukkan beberapa kriteria pemilihan media pembelajaran yang baik, prinsip pengembangan media pemebalajaran dan produk media pembelajaran PAI yang sudah melalui uji validasi dan uji coba lapangan kepada guru dan siswa sehingga memenuhi kriteria media pembelajaran yang baik

Perancangan dan Pembuatan Propeller Perahu Nelayan Dengan Metode Investment Casting Pola Lilin dan Cetakan Pasir

Propeller atau baling-baling adalah salah satu bagian yang penting dalam perahu nelayan. Geometri propeller yang rumit membuat proses permesinan sulit untuk dilakukan dan memerlukan banyak biaya. Tujuan penelitian Tugas Akhir ini adalah membuat propeller perahu nelayan dengan metode investment casting untuk mengurangi proses permesinan dan mendapatkan geometri produk yang akurat. Selain itu menganalisa geometri, kerataan dan cacat yang mungkin terjadi pada produk akhir pengecoran. Pemodelan dilakukan pada jenis propeller perahu nelayan yang sudah ditentukan. Cetakan master die propeller dibuat menggunakan material silicone rubber RTV 497. Cetakan investment casting yang digunakan berbahan pasir silika mesh 10 -30 dan mesh 80-100, gypsum, serta alumina. Pola lilin yang digunakan berbahan lilin parafin. Cetakan investment casting dilakukan proses sintering pada suhu 250°C selama 30 menit. Material pengecoran yang digunakan adalah aluminium paduan Al-Si yang dileburkan pada suhu 770°C. Hasil penelitian menunjukkan pada produk pengecoran ditemukan penyusutan sebesar 2.95 – 8.08 % dengan menggunakan alat ukur vernier caliper dan 2.83 – 8.34 % dengan pengukuran 3D Scan. Pada pengukuran kerataan permukaan daun propeller ditemukan perbedaan tingkat kerataan permukaan daun propeller disebabkan karena propeller coran mengalami penyusutan dan cacat kekasaran erosi. Hasil identifikasi cacat pengecoran menunjukkan pada pemeriksaan visual ditemukan cacat ekor tikus, sirip, lubang jarum, membengkak, penetrasi logam, salah alir dan kekasaran erosi. Sedangkan pada pemeriksaan dengan cairan dye penetrant ditemukan cacat rongga penyusutan dan udara

PENGKAJIAN FLEXIBLE COUPLING VICTAULIC TYPE 75 DIAMETER 4 INCH DENGAN PENGUJIAN KEKERASAN, KOMPOSISI KIMIA DAN METALOGRAFI

Flexible coupling is a pipe connecting device is equipped with vibration damping piping system. One example of flexible coupling on the market is victaulic flexible coupling type 75. To determine the quality of flexible coupling, to be known mechanical properties and micro structure of the material. Tests conducted include hardness testing, chemical composition testing and metallographic. Test results showed that the material used as a flexible coupling it is nodular cast iron, (ductile iron). Hardness values for ductile iron 172.9 BHN, while the tensile strength value about 596.59 MPa obtained by converting the value of hardness of the material. From the metallographic testing is known that ferrite content is more dominant than the pearlite will enhance the material toughness. The element carbon is more than usual ductile iron standards of more than 4.584% so that the hardness will increase the value of flexible coupling

Aplikasi Peralatan Tekuk Plat untuk Industri Berbasis Logam

The potential, opportunities and advantages of the metal industry in Mliwis Cepogo have not been able to drive the people's economy optimally. This condition will be even more complicated because the metal industry, especially in production units, is constrained by equipment for workmanship. The realization of service activities at Zazen Art Galeria partners is principally carried out by strengthening the copper engraving industry, especially production units with the application of plate bending machines. The application of plate bending machines can improve product quality and quantity and increase productivity in production units. The plate bending machine's performance can be improved by applying hydraulics as a plate driver/presse

Pengaruh Parameter Proses Milling pada Austempered Ductile Iron (ADI) Terhadap Kekasaran Permukaan Benda Kerja dan Chip Thickness Ratio

Austempered ductile iron (ADI) is a difficult material for machining, even though ADI is believed to have several advantages such as strength, ductility, high toughness, fatigue resistance, good dynamic wear resistance, has a good strength-to-weight ratio, easy to manufacture  and easy to cast that causes it to be widely used in various applications.  This study investigates the effect of milling parameters on surface rougness and chip thickness ratio on milling of ADI. To produce ADI, ductile irons  were first austenitized in furnace at 900oC for 1 hour and then they were quenched in salt bath at 375oC for 1 hour. The work material was machined with uncoated carbide tool. The tool was 20 mm in diameter. The cutting experiments were carried out in the dry mode. The feed was varied from 0.05 to 0.1 mm/tooth for cutting speed ranging from 15 m/min to 25 mm/min and depth of cut ranging from 0.1 mm to 0.3 mm. The surface roughness was measured using the Mitutoyo SJ-201, surface roughness machine. The chip thickness was measured using software Image J from the photograph produced by digital microscope endoscope. The results show that connected and loose chips were produced. Long and continuous chips were not found in this study. The effects of cutting speeds, feeds and depth of cut on surface roughness and chip thickness ratio  are reported in this pape

Analisis Struktur Mikro Dan Sifat Mekanis Hasil Las Titik Dan Brazing Untuk Industri Rumahan

In the welding process there are several factors that determine the success of welding. The alteration of microstructure of joined metals are expected to change the structure of the material into more dense to make connections become stronger. In this study, the material used is ferrous steel plate with a maximum thickness of 1mm. In order to know the results, It required to use some variation of a parameter such as pressing time and plate thickness used for metal welding process. The process used home brazing welding machine, the connections are welded and welding receive local heat and during the process the temperature is constantly changing so that the temperature distribution is uneven. As a result of this stretch then analyzed the results of the micro structure of the welding process using brazing home welding machine. After analysis of the microstructure was done then analyze the mechanical properties of the weld joint, all this analysis needs to be done in order to ascertain the connection is really strong welds and brazing machine can be used for home-scale cottage industry. The results of this study indicate that nugget on hardness Vickers test has a value higher than of the base metal which is 172.78 for 8.6 A current and welding time 20 second 191.58 for 6 A current and welding time of 10 second, and the value of base metals 165.7 so percentage obtained with increasing force to the current value of 8.6 A is 7.1 % and for the current 6 A 25.8

Physical Characterization of Alumina (Al2o3) Based Refractory Applied on Induction Furnace Lining

The broad variety of pyro-processing applications across industry demands great diversity in the supply of refractory materials. In fact, many of these materials have been developed specifically to meet the service conditions of a particular process. The characteristic properties of each refractory class are a function of both their raw materials base and the methods used to manufacture the refractory products. This study aims to characterize alumina (Al2O3) based refractory materials applied on induction furnace lining based on its physical properties such as: the shape and grain size; chemical composition; and density of the specimens which sintered at various temperature. From the X-ray Diffraction Test compared with specification data from the manufacturer, the main composition of the base refractory material used in this study is alumina (Al2O3) with a low amount (less than 10%) of magnesia (MgO) and silica (SiO2). Alumina refractory material consists of coarse grains (with its size larger than 0,85mm) and fine grains (size is equal to 0,15mm or smaller). Grains shape of the aggregates are mostly angular with its sharp edges. Values of density at temperature 1100C, 10000C, 13000C, 15000C in sequence are 2,92 g/cm3; 2,66 g/cm3; 2,80 g/cm3; 2,98 g/cm3. Density of the refractory will increase as the increase of sintering temperature