36 research outputs found
Pengaruh kadar tambang (Cu) terhadap sifat mekanis aluminium matrix composite berpenguat alumina dibuat secara ekstruksi
No full textThe objective of this research is to find effect of copper on the mechanical properties of aluminium matrix composite (AMC), which is reinforced by alumina and made using hot extrusion. The amount of copper of 1;3 and 5wt% and 10wt% local alumina were added to the aluminium fine powder as matrix. Each was mixed using rotary mixer for 2hr. The mixture was then uniaxially compacted with a pressure 100 MPa to produce green body. The green body was then extruded at 600°C and ratio 4/9. Each composites was tested of bending strength, porosity. hardness and wear rate. From the data testing can be found effect of copper on the mechanical properties of AMC. The results show that mechanical properties decrease with inceasine of fraction of copper. The best mechanical properties such as bending strength, porosity, hardness and wear rate is on the AMC with 1wt% copper, there are 387 MPa, 0,5%, 80 VHN and 0,013 mg/MPa.m, respectivel
Pengaruh pemanasan selama pengelasan terhadap sifat mekanik hasil pengelasan baja K100 special K
No full textMengatur Kapasitas Pompa Plunyer Kerja ganda
No full textKapasitas pompa plunyer tergantung pada diameter plunyer, panjang langkah plunyer dan kecepatan putar poros penggerak. Dari ke tiga parameter tersebut yang bisa dirubah adalah panjang langkah dan kecepatan putar poros penggerak, tetapi kadang-kadang kecepatan putar poros penggerak sudah konstan sehingga untuk mengatur kapasitas pompa hanya dapat dilakukan dengan mengatur panjang langkah plunger dengan bantuan sepal!\u27 luncur. Telapi pengaturan tersebut hanya bisa dilakukan untuk pompa kerja tunggal (single acting). Untuk pompa kerja ganda kapasitas dapat diatur denganbantuan katup pengatur yang berhubungan dengan saluran tekan. Pembukaan dan penutupan katup digerakkan oleh nok (hubungan), sehingga kalau kapasitas terlalu besar air dari saluran tekan dapat dialirkan balik masuk ke dalam silinder pada sisi isap
Kekerasan dan laju keausan komposit aluminium diperkuat dengan keramik Zirconia yang dibuat dengan metode metalurgi serbuk
No full textPenelitian ini bertujuan untuk memanfaatkan bahan Zirconia (ZrO2)sebagai penguat komposit Aluminium Matrix Composite (AMC). Serbuk ZrO2 merupakan bahan kramik yang keras dan memiliki ketahanan terhadap temperature tinggi. Serbuk ZrO2 sebanyak 0%; 2,5%; 5%; 7,5%; 10%; 12,5% dan 15% fraksi berat dicampur dengan serbuk aluminium (ukuran serbuk lebih kecil dari 40 µm). Setiap campuran diaduk menggunakan turbula mixer selama 2 jam. Campuran serbuk aluminium dan ZrO2 dikompaksi secara uniaksial dengan tekanan 300 MPa dan diikuti sintering tanpa tekanan dengan lingkungan gas argon pada temperatur 600°C . Densitas relatif, kekerasan Vikers, dan laju keausan AMC diuji. Hasil pengujian menunjukkan bahwa kekerasan meningkat seiring dengan peningkatan fraksi berat ZrO2 sampai 5% sementara laju keausan turun. Densitas relatif, kekerasan Vikers dan laju keausan berturut turut pada komposit dengan fraksi berat ZrO2 5% adalah 91%, 35 VHN dan 0,01 mg/(MPa.M
Pengaruh Arah Pengerolan Terhadap Ketanggujan Dan Laju Perambatan Retak Pelat Kapal Grade A
No full textAn Investigation of the effect of rolling on the fracture toughness and crack growth rate for ship steel has been performed. The testing was carried out using compact tension specimens (CTS) on the field to be investigated. The CTS orientation was chosen to be parallel and perpendicular to the rolling orientation. The fracture toughness and crack growth rate tests were conducted in accordance with ASTM standard E 399-83 and ASTM standard E 647 - 86a respectively.
The test \u27results show that the fracture toughness of perpendicular to the rolling direction is slightly higher than of parallel direction. The crack growth rate depends on the range of the stress intensity factor (AK). For low value of AK the crack growth rote is the same for all directions, and for high value of AK, Perpendicular to the rolling direction shows higher than parallel to the rolling direction
Pengaruh Pemanasan Lokal Terhadap Ketangguhan dan Laju PerambatanRetak Plat Baja "Grade B".
No full textABSTRACT
An Investigation of the effect of local heating on the fracture toughness and crack growth rate for ship plates has beee performed. The local heating was carried out using a welding system on the field to be investigated.
A number of plates, which has been welded, was cut to produce a number of specimens which consists of fracture toughness specimens, crack growth rates specimens and other specimens needed. The main test in the research was fracture toughness and crack growth rate. The fracture toughness and crack growth rate were conducted in accordance with AsTm standard E399-83 and ASTM standard E647-86a respectively.
The test results show that the fracture toughness at the HAZ is slightly higher than at the base metal. The crack growth
rate depends on the range of the stress intensity factor (AK). For low value of AK, the crack growth rate at the HAZ is 35%,i lower than at the base metal, and for high value of AK, it shows 46% lower than at the base metal.
Kata Kunci: Perambatan retak, plat baja, perpatahan kritis, plate grad
OPTIMASI PROSES PEMBUATAN BRIKET BIOMASSA MENGGUNAKAN METODE TAGUCHI GUNA MEMENUHI KEBUTUHAN BAHAN BAKAR ALTERNATIF YANG RAMAH LINGKUNGAN (Optimization of Biomass Briquettes Production Process Using Taguchi Method)
No full textABSTRAK
Permasalahan yang dihadapi pembuat dan pengguna briket adalah briket yang dihasilkan kualitasnya rendah ditinjau dari nilai kalor. Tujuan penelitian ini adalah menentukan kualitas briket terbaik dari limbah biomassa dalam memenuhi kebutuhan bahan bakar alternatif rumah tangga yang murah dan ramah lingkungan guna mewujudkan masyarakat mandiri energi. Metode yang digunakan untuk menentukan kualitas briket adalah metode Taguchi. Variabel bebas dalam penelitian ini adalah tekanan pengepressan, waktu penahanan, model cetakan, suhu pengeringan, lama pengeringan dan komposisi bahan, sedangkan variabel terikat adalah nilai kalor briket. Hasil penelitian menunjukkan bahwa kualitas briket terbaik ditinjau dari nilai kalor tertinggi yaitu pada setting parameter A2B1C2D2E2F1, artinya tekanan pengepressan 225 kg/cm2, waktu penahanan 5 menit, model cetakan sarang tawon (kotak), suhu pengeringan 60 °C, lama pengeringan 3 hari, perbandingan limbah jarak pagar : arang sekam : arang tempurung kelapa : perekat adalah 5 : 3: 2 : 1. Rata-rata nilai kalor biobriket yang dihasilkan sebesar 5.323 kal/g. Hal ini menunjukkan bahwa briket mempunyai nilai kalor yang tinggi dan memenuhi SNI, sehingga briket layak untuk memenuhi kebutuhan bahan bakar alternatif yang ramah lingkungan.
ABSTRACT
Problems that encountered on manufacturers and users of briquettes is low quality of the briquettes in terms of heat value. The aim of this research is to determine the best quality of the briquette which is made from biomass waste. The briquette is expected to be used to fulfill the need of inexpensive and environmentally friendly of alternative household fuel, by which the energy independent community could be realized.The method used to determine the quality of the briquette is Taguchi method. The independent variables involved are compressive strength, holding time, mold model, drying temperature, drying time and material composition. The dependent variable is the highest heat value of the briquette. The results show that based on the highest heat value, the best briquette quality is parameter setting of A2B1C2D2E2F1, which means that the compressive strength is 225 kg/cm2, the holding time is 5 minutes, the mold model is honeycomb of box, drying temperature is 60 °C, drying time is 3 days and the ratio of Jatropha Curcas waste : rice husk charcoal : coconut shell charcoal : adhesive is 5 : 3: 2 : 1. The average heat value of briquette is 5,323 cal/g. This matter the briquettes show that high heat value and feasible of recommendation by SNI, and so briquette decent to fulfill the need of environment friendly alternative fuel
Utilization of fly ash waste as reinforcement of aluminium matrix composite produced using powder metallurgy (Pemanfaatan Limbah abu terbang sebagai penguat aluminium metal matrix composite dibuat dengan cara metalurgi serbuk)
No full textAluminium matrix composite (AMC) has been prepared from aluminium fine powder as a matrix and fly waste as reinforcement. In this research the amount of fly ash as much as 2,5, 5, 7,5 and 10 wt% was added to the aluminium fine powder. The mixture was compacted using uniaxial with a pressure of 100 MPa and it was pressureless sintered in argon atmosphere at various temperature of 500°, 525°, 550°, 575° and 600°C. Bending strength of AMC was determined using four point bending, hardness was tested using Vickers method, wear rate was tested using pin on disk method. Porosity was tested using Archimedes method and the micro structure was observed using SEM. The result shows that fly ash can be used as reinforcement of AMC. The bending strength and Vickers hardness of AMC increase, wear rate and porosity of AMC decrease with increasing the fly ash content up to 7.5 wt%, while fly ash higher than 7,5 wt% causes a decrease. Porosity, bending strength, wear rate and hardness of AMC are 5,4%, 68,5 MPa, 0,0571 mg/(MPa.m) and 62,6 VHB, respectively. It shows that bending strength, hardness and wear resistance of AMC are higher than pure aluminium
Mechanical Properties of Aluminum/fly Ash Composites Produced by Hot Extrusion
No full textThis research aims to investigate mechanical properties of aluminum matrix composites reinforced with fly ash (AMC/Fly ash) produced using hot extrusion.AMC/Fly ash was prepared from aluminum fine powder as matrix and fly ash as reinforcement. The various amount of fly ash of 5%; 7.5%; 10%; 12.5% and 15% wt were added to the aluminum fine powder. Each composition was mixed using rotary mixer for 3 hours. The mixture was compacted using uniaxial pressing with a pressure of 100 MPa to produce green body. The green body was hot extruded with an extrusion ratio of 0.25 and temperature of 600ºC. Bending strength, Vickers hardness, wear rate and porosity of the AMC/fly ash were measured. The microstructure was observed using SEM. The results show that mechanical properties of the composites such as bending strength and Vickers hardness increase, porosity and wear rate decrease with increasing fly ash content up to 12.5 wt %. Above 12.5 wt % of fly ash those mechanical properties of composites seems to be inverse. The properties of AMC/12.5 wt % fly ash produced using hot extrusion from green body showing the best properties in term of the bending strength, Vickers hardness, porosity and wear resistance, that are 302 MPa; 79 VHN; 0.73 % and 0,0095 mg/(MPa.m), respectively.</jats:p
Pemanfaatan Limbah Abu Terbang Sebagai Penguat Aluminium Matrix Composite
No full textPenelitian ini bertujuan untuk memanfaatkan abu terbang sebagai penguat komposit bermatrik aluminium (AMC). Abu terbang merupakan limbah pembakaran batu bara pada pembangkit listrik tenaga uap. Abu terbang sejumlah 2,5%; 5%; 7,5% dan 10% berat tercamput dengan serbuk aluminium (ukuran serbuk lebih kecil dari 40 µm). Setiap campuran diaduk menggunakan rotay mixer selama 3 jam. Campuran aluminium dan abu terbang dikompaksi secara uniaksial dilanjutkan kompaksi secara isostatik dengan tekanan 100 MPa dan diikuti sintering tanpa tekanan dengan lingkungan gas argon dan variasi temperatur 500°C, 525°C, 550°C, 575°C dan 600°C. Kekuatan banding, kekerasan Vickers, ketahanan aus dan densitas komposit diuji serta struktur mikro diamati menggunakan SEM. Hasil pengujian menunjukkan bahwa sifat mekanis meningkat seiring dengan peningkatan fraksi berat abu terbang sempai 5% berat, selebihnya terjadi penurunan. Kekuatan banding, kekerasan Vickers, porositas dan laju keausan berturut-turut 74 MPa, 66 VHN, 4,5% dan 0,04 mg/(MPa.m)
