Claim Missing Document
Check
Articles

Found 25 Documents
Search

FRACTURE SURFACE PADA KOMPOSIT HIBRID BERBASIS FIBERGLASS DAN COIR AKIBAT PENGARUH MOISTURE CONTENT Mastariyanto Perdana; Jamasri Jamasri
Jurnal Momentum ISSN 1693-752X Vol 17, No 1 (2015): Volume 17 No 1 Tahun 2015
Publisher : ITP Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (552.614 KB)

Abstract

Salah satu material teknik yang sangat banyak digunakan dibidang keteknikan adalah komposit. Ini disebabkan komposit memiliki sifat ringan dan relatif kuat. Namun, komposit yang berbasis serat sintesis dikurangi penggunaannya untuk mendapatkan sifat ramah lingkungan sehingga penelitian ini menggunakan serat hibrid dengan fraksi volume yang terdiri dari 12% fiberglass dan 18% coir. Fraksi volume antara serat hibrid dan epoksi adalah 30:70. Penelitian ini bertujuan untuk mengetahui bentuk patahan (fracture surface) komposit sebagai akibat pengaruh dari moisture content. Komposit direndam dalam air dengan variasi perendaman 6, 12, 18, dan 24 jam untuk mengetahui pengaruh dari moisture content tersebut. Hasil pengujian menunjukkan bahwa sebagai akibat moisture content menyebabkan terjadinya pull-out pada serat coir dan fiberglass pada komposit hybrid. Moisture content menyebabkan menurunnya interfacial bonding antara serat coir dan matrik sehingga akan menyebabkan terjadinya penurunan kekuatan dari komposit.
PEMANFAATAN LIMBAH ABU TERBANG SEBAGAI PENGUAT ALUMINIUM METAL MATRIX COMPOSITE DIBUAT DENGAN CARA METALURGI SERBUK Subarmono, Subarmono; Jamasri, Jamasri; Wildan, M.W.; Kusnanto, Kusnanto
Jurnal Manusia dan Lingkungan (Journal of People and Environment) Vol 18, No 2 (2011)
Publisher : Pusat Studi Lingkungan Hidup Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1.84 KB)

Abstract

Pada penelitian ini telah dilakukan pembuatan aluminium matrix composite (AMC) dari serbuk aluminium sebagai matrik dan limbah abu terbang sebagai penguat. Sejumlah abu terbang yaitu 2,5; 5; 7,5 dan 10% berat ditambahkan pada bubuk aluminium. Campuran abu terbang dan serbuk aluminium dikompaksi secara aksial dengan tekanan 100 MPa dan dilanjutkan dengan proses sintering tanpa tekanan dengan lingkungan gas argon pada berbagai temperatur yaitu 500˚, 525˚, 500˚, 575˚ dan 600˚C. Pengujian kekuatan bending menggunakan metode four point bending, kekerasan menggunakan metode Vickers, laju keausan menggunakan metode pin on disk dan porositas menggunakan metode Archimedes serta struktur mikro diamati menggunakan SEM. Hasil penelitian menunjukkan bahwa kekuatan bending dan kekerasan meningkat, laju keausan dan porositas menurun seiring dengan bertambahnya abu terbang pada AMC sampai 7,5% berat, namun bila kandungan abu terbang lebih dari 7,5% berat sifat AMC menunjukkan kebalikannya. Porositas, kekuatan bending, laju keausan dan kekerasan terbaik yaitu pada AMC dengan 7,5% berat abu terbang berturut-turut sebesar 5,4%, 68,5 MPa, 0,0571 mg/(MPa.m) and 62,6 VHN. Hal ini menunjukkan bahwa kekuatan bending, kekerasan dan ketahanan aus AMC lebih baik dibanding aluminium murni.
Development of Low Frequency Vibration Method of Direct-Write Deposition Relevant to Layer Manufacturing Application Widyanto, Susilo; Tontowi, Alva; Jamasri, Jamasri; Budi Rochardjo, Heru Santoso
Makara Journal of Technology Vol 9, No 2 (2005)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (143.298 KB) | DOI: 10.7454/mst.v9i2.101

Abstract

The research of deposition process is the first step in development process of multi materials selective laser sintering. The deposition process enables to settle multi materials powder in horizontal formation on one layer. In this research we use low frequency (70 - 200Hz) to vibrate a hopper nozzle in which powder is settled. The research method consists of two steps, the first step is to determine flow-ability parameters and the second is to join flow ability parameter with other parameters such that the line width can be controlled. The results show that the line width depends on uniformity of particle size, particle size, frequency of vibration, deposition gap, particle shape and feed-rate of hopper-nozzle.
Determination of Operation Condition and Product Dimension Accuracy Optimization of Filament Deposition Modelling on Layer Manufacturing Application Widyanto, Slamet; Tontowi, Alva Edy; Jamasri, Jamasri; Rochardjo, Heru Santoso Budi
Makara Journal of Technology Vol 10, No 2 (2006)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (269.348 KB) | DOI: 10.7454/mst.v10i2.117

Abstract

Layer manufacturing process has proven as a process that can produce a high complexity mechanical part. Now, Improvement of LM methods continuously conduct that is aimed to increase precessions and efficiency of these processes. Pressure filament deposition modelling is a form of layer manufacturing process that is designed to produce a plastic part with controlling its semisolid phase. In this research, the equipment of filament depositor is designed and tested to make the product filament deposition. With operation condition observation, the optimal temperature and pressure of deposition process was determined. These experiments used PVC as crystalline material and  polypropylene as amorphous material. To optimize this process, the tensile strength and density test were conducted. The shape of tensile test specimens is based on ASTM 638 standard and made in 3 orientations deposition path, namely: in 0 degree, 45 degree and 90 degree from load force axis. To found the most accurate dimension, controlling the time delay, temperature of build part, feeding speed and variation deposition path was conducted. The results of experiments show that the filament deposition method can only be applied for amorphous material in which it has a semisolid phase. From the tensile strength test, the binding strength among filaments is 0.5 kg/mm2, 20% of the tensile strength of filament. And the density of a sample product, which used the filament diameter of 0.8 mm, is 0.7668 g/cm3. Accuracy of product dimension can be increased by: controlling time delay in location where the motion orientation of hopper filament is changed and controlling temperature of build part surface.
Perilaku water absorption pada komposit hybrid serat agel tenun dan serat gelas H. Hestiawan; J. Jamasri; K. Kusmono; A. Puspawan
Dinamika Teknik Mesin Vol 11, No 2 (2021): Dinamika Teknik Mesin
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (459.641 KB) | DOI: 10.29303/dtm.v11i2.457

Abstract

This study aimed to investigate the effect of alkali treatment and stacking sequences on water absorption and flexural strength in woven agel and glass fibers reinforced hybrid composites. The research materials are woven agel fiber, E-200 glass fiber, unsaturated polyester resin Yukalac 157 BQTN, and catalyst of methyl ethyl ketone peroxide (MEKP). The alkali treatment is carried out on the woven agel fibers by soaking the fiber in 5% NaOH solution for 1 hour. Then the fiber is washed with fresh water and dried for 48 hours. Manufacturing techniques used vacuum bagging with suction pressure of 70 cmHg at room temperature. The amount of reinforcing fiber 7 fibers consists of 3 glass fibers and 4 agel woven fibers. The water absorption test uses a 3.5% NaCl solution for 1080 hours at room temperature. Water absorption test specimens based on ASTM D570 standard. The research results showed that alkali treatment with glass fiber arrangement on the specimen surface effectively decreased water absorption and increased the flexural strength of woven agel and glass fibers hybrid composites. This can be seen from the decrease in water content in equilibrium by 8.67%, the diffusion coefficient of 5.74 x 10-12 m2/s, and the flexural strength before and after immersion, which are 135 MPa and 125 MPa respectively.
INFLUENCE OF REMELTING ON ALUMINUM ALUMINUM RAIN Aris Budiyono; Jamasri Jamasri
Jurnal Penelitian Saintek Vol 15, No 2: Oktober 2010
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5873.567 KB) | DOI: 10.21831/jps.v15i2.1753

Abstract

The purpose  of this research is to observe the effect of remelting  on fatigue  crack growth rates of the aluminum  alloys. The material  used in this research was selected  aluminum scraps.  The material  was melt and cast at temperature  of  745°C in the metal molding, then was made specimen  according  to ASTM  E. 647. The remelting  was done three times at the same  condition.  The fatigue  crack growth  rate  testing  was performed  in a room temperature  condition with a constant load amplitude and the load ratio was maintained to be 0,3.The experiment result show that remelting can increase fatigue  crack growth rates whichwas shown by increasing ofn  exponential  values (I" remelting  was 4,4285 MFa.mo,s, 2nd4,5562 MFa.mo,s, and 3rd  4,6078 MFa.mo,5)Key words: remelting, fatigue  crack growth rates, aluminum alloys
INFLUENCE OF SINTERING TEMPERATURE AND HOLDING TIME ON TENSILE STRENGTH AND SHRINKAGE OF PVC SPECIMEN ON INDIRECT PRESSURE-LESS SINTERING PROCESS Widyanto, S. A; Riyadi, S; Tontowi, A. E; Jamasri, Jamasri; Rochardjo, H. S
Mesin Vol 21, No 1 (2006)
Publisher : Mesin

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (331.211 KB)

Abstract

Sintering process has proven to be a manufacturing process that can produce a mechanical part with high geometric complexity. Development of alternative sintering process is continuously conducted to find the most inexpensive process. A solution process which is called indirect pressure-less sintering were proposed in this research. Generally this process of making a mechanical part is initiated with arranging powder by deposition machine, and continued by sintering process in conventional furnace. Optimal parameters that consist of sintering temperature and holding time in this process were optimized in this paper. PVC powder and sand casting (silica) were used as a material product and supporting powder respectively. The variations of sintering temperature are 100, 105, 110, 115 and 120°C, while the holding times are 2, 4, 6 and 8 hours. The optimal parameters were found by measuring tensile strength and shrinkage of specimen. The experiment results showed that dimensional stability of specimen can not be maintained for sintering temperature of 115°C with holding time longer than 2 hours. In sintering temperature higher than 120°C, PVC material directly starts to melt so that the volume of specimen increased. This was caused by binding of supporting powder. The strength of binding mechanism was measured when sintering temperature was higher than 107°C. In sintering temperature of 113°C with varying the holding time (2-8 hours) gave the longest variation of tensile strength.
RELIABILITY-CENTERED MAINTENANCE (RCM) EVALUATION METHOD IN THE INDUSTRY APPLICATION, CASE STUDY: FERTILIZER COMPANY, INDONESIA Khasanah, Rahayu; Dawal, Siti Zawiah Md.; -, Jamasri
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 8 No 1 Agustus 2015
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (420.004 KB) | DOI: 10.34151/technoscientia.v8i1.190

Abstract

Nowadays, Reliability-centered Maintenance (RCM) has become the solution to determine the type of maintenance tasks and inspections needs to be performed to the assets in achieving effective and efficient maintenance. However, implementing RCM is not enough to achieve optimization of maintenance planning. The evaluation, as one of the important point should be done to prove the benefits of RCM and to continuously improve the maintenance planning. In this study, the effects of RCM implementation in the industry application were evaluated, as a step for continuous improvement in RCM application. The case study is an Ammonia plant in a fertilizer company in Indonesia. This research evaluates the RCM effects by investigating and analyzing Downtime Loss and Mean Time between Failures (MTBF). The problems in RCM implementation in the case study also investigate as a basic for giving the recommendation to the company as a way to improve the RCM implementation. In general, the findings from the investigation of case study affirm that RCM implementation do improve the plant performance which are showed by decreasing of Downtime Loss and Mean Time between Failures. The significant problems that become pitfalls in RCM implementation process are about the worker’s culture and understanding on the RCM process. Overall, the study shows that RCM implementation brings many benefits to the company by decreasing the Downtime Loss and Mean Time between Failures which can be resulted as the higher profit for the company.
PENGARUH PENGELASAN FCAW TANPA DAN DENGAN PENAMBAHAN PANAS TERHADAP PERUBAHAN SIFAT MEKANIK DAN STRUKTUR MIKRO SAMBUNGAN LAS Subeki, Nur; -, Jamasri; Ilman, M.N.; Iswanto, P.T.
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 7 No 2 Februari 2015
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (777.254 KB) | DOI: 10.34151/technoscientia.v7i2.204

Abstract

The Welding processes are delivery used joining steel, especially used in civil construction, piping and ship manufacturing. Many of the benefits that can be obtained from welded joint is the joining can be cheap, rapid manufacturing, varied shape and lighter construction. One of the welding techniques that is widely used for joining the steel construction is Flux Core Arc Welding (FCAW). The problem that found in welding joints is the tensile strength in welding area is low and uneven hardness in the weld joint. The aim of this research was to determine the mechanical properties of FCAW Welding process and find out micro structures formed by the addition of heat around the welding.In this research, FCAW welding has been divided into two groups; the ones group is manufacturing without addition of heating, and the second group is manufacturing by heating 200 °C. Every group of manufactures would be test by chemical compositions, macro photos, micro photos, tensile strength and hardness number. The results of this research shows that the addition of heat at 200 °C could be increase the yield strength and ultimate strength. The heating also could be very small impact on the change in the hardness of weld area, but it could be reduce the hardness in HAZ area significantly. Micro structure formed then the weld area has been dominated by acicular ferrite micro structure, grain boundary ferrite dominate in coarse HAZ, the pearlite and ferrite with grain aggrandizement take place in smooth HAZ and base metals.
Pengaruh Perlakuan Alkali-silan terhadap Sifat Mekanis Komposit Hibrid yang Diperkuat Serat Agel dan Serat Gelas : Effect of Alkali-Silane Treatment on Mechanical Properties at Glass Fabric and Woven Agel (Corypha gebanga) Reinforced Hybrid Composites Hendri Hestiawan; Jamasri; Kusmono
Jurnal Metalurgi dan Material Indonesia Vol. 3 No. 1 (2020): April
Publisher : Badan Kerja Sama Pendidikan Metalurgi dan Material (BKPMM)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The aim of this research is to investigate the effect of alkali-silane on mechanical properties at glass fabric and woven agel (Corypha gebanga) reinforced hybrid composites. The materials used are woven agel fiber, glass fabric, unsaturated polyester resin of yukalac 157 BQTN, and catalyst of methyl ethyl ketone peroxide. Manufacturing techniques used vacuum bagging with a suction pressure of 70 cmHg at room temperature. The woven agel were treated with 4% sodium hydoxide solution for 1 hour, 5% silane solution for 3 hours, and a combined sodium hydoxide and silane solution. The tensile, flexural, and impact test specimens based on ASTM D 638-02, D 790-02, and D 5942-96 standards respectively. The results of tensile, flexural, and impact tests showed that the highest tensile and flexural strength, and impact toughness ​​were obtained on alkali-silane treated hybrid composites, i.e. 78 MPa, 116 MPa, and 38 kJ/m2 respectively. It can be concluded that the alkali-silane treatment effectively improves the mechanical properties of at glass fabric and woven agel reinforced hybrid composites