Article Per Year (5 Year)
p-Index From 2021 - 2026
1.704
P-Index
This Author published in this journals
All Journal Rekayasa Mesin International Journal of Mechanical Engineering Technologies and Applications (MECHTA) Proceeding ISETH (International Summit on Science, Technology, and Humanity) GMPI Conference Series
Djarot B. Darmadi, Djarot B.
Unknown Affiliation
Humanities Automotive Engineering Computer Science & IT Decision Sciences, Operations Research & Management Energy Engineering Industrial & Manufacturing Engineering Mechanical Engineering Medicine & Pharmacology Physics Social Sciences Other

Published : 16 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 16 Documents
Search

 1   2 
Hardening Baja AISI 1045 Menggunakan Gel Aloe Vera Sebagai Media Pendingin Budiyanto, Eko; Choiron, Moch. Agus; Darmadi, Djarot B.
Jurnal Rekayasa Mesin Vol. 7 No. 2 (2016)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2016.007.02.3

Abstract

Quenching is a cooling method of heat treatment for metal hardening. Quenching refers to the process of rapidly cooling metal parts from the austenitizing or solution treating temperature, typically from within the range of 815 to 970 °C for steel. The selection of a quenchant medium depends on the hardenability of the particular alloy, the section thickness and shape involved, and the cooling rates to achieve the desired microstructure. The liquid quenchants of oil is commonly used in industrial manufacture. But, oil is not environmental. The aim of this research research is to find new quenchant for change oil as quenchant to more environmental. Gel aloe vera is purposed for it. The material used in this study is AISI 1045 steel. Cooling curve and cooling rate is measured by finite element model, ANSYS APDL 14.5. True experimental is done to view microstructure and measure hardness of steel. Simulation result shown that gel aloe vera has almost similar cooling curve and cooling rate with oil. Microstructure result of steel for gel aloe vera as quenchant is martensite in surface, bainite in center, and pearlite in between surface and center. Hardness number of steel for gel aloe vera as quenchant is 189.63 HVN in surface, 182.566 HVN in center, and 162.866 HVN in between surface and center. By simulation and true experimental analisys concluded that gel aloe vera has opportunities to change oil as quenchant for hardening process.
PENGARUH KOMPOSISI LAPISAN NI-CR PADA BAJA ASME SA 210 C TERHADAP LAJU EROSI SUHU TINGGI Utomo, Slamet Prasetyo; Darmadi, Djarot B.; Widodo, Teguh Dwi
Jurnal Rekayasa Mesin Vol. 15 No. 1 (2024)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/jrm.v15i1.1501

Abstract

The purpose of this study was to determine the high temperature erosion rate of the NiCr coating on ASME SA 210 C steel using the combustion oxy fuel thermal spray method. In Circulating Fluidized Bed (CFB) boiler, there is circulation of fly ash, silica sand and air in a high temperature environment which causes erosion. High temperature erosion can be minimized by using Ni-Cr alloy coating sing the combustion oxy fuel thermal spray method. NiCr alloy is proved a able to provider a metal alloy layer composition that can withstand temperatures of 600°C with a fly ash impact speed of 200m/s. The metal alloy compositions that have been studied are NiCr, NiCrCo, NiCrWc, NiCrWcCo, and NiCrCoMo. The results of this study indicates that metal alloys are generally atteche to the substrate and withstand at a high temperatures (600°C). The highest hardness provide by NiCrWcCo alloy which is 177.46 HV. The lowest hardness is found in the composition of the NiCrCo alloy (161.71 HV). The lowest high temperature erosion rate was found in the NiCrWcCo alloy, which was -0.00481 gram/minute. This low erosion rate because the NiCrWcCo alloy produces a good weeting effect for metal alloys and has a high hardness value.
DURASI PERAWATAN OPTIMUM UNTUK FASILITAS PRODUKSI MINYAK DAN GAS DI KILANG TUBAN EAST JAVA Yahya, Indra Nur; Mahatwan, Dian; Setiawan, Ari; Darmadi, Djarot B.
Jurnal Rekayasa Mesin Vol. 15 No. 1 (2024)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/jrm.v15i1.1839

Abstract

Electric Submersible Pump (ESP) is one of the most critical oil & gas equipment in Tuban East Java (TEJ) field. This research applies Reliability Centered Maintenance (RCM) to oil & gas to optimize maintenance methods for ESP at the TEJ field. The RCM was applied based on the historical failure events at equipment which caused Loss Production Opportunity (LPO). Start with Pareto chart, the RCM followed by Failure Modes and Effect Analysis (FMEA) that produced the Risk Priority Number (RPN) for the 80% problems. The last step provided the optimum maintenance periods using Weibull’s statistic. The result shows that flat cable in ESP has the highest RPN. Flat cable requires an optimum maintenance period of 509 days and a total cost of US$59,342. The total cost consists of Periodic Maintenance (PM) and Risk costs.
Lap Joint Carbon Steel ST 37 and Aluminum 6061 with Friction Stir Welding (FSW) Setiawan, Widia; Darmadi, Djarot B.; Suprapto, Wahyono; Soenoko, Rudy
Proceeding ISETH (International Summit on Science, Technology, and Humanity) 2016: Proceeding ISETH (International Conference on Science, Technology, and Humanity)
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23917/iseth.2361

Abstract

In this research, Aluminum 6061 and Carbon steel ST 37 sheet were lap joined by friction stir welding. A hardened medium carbonese steel (EMS 45) was used as rotary Probe. The microstructures of the joining inter-metallic compounds were observed by scanning electron microscopy, microstructure photograph, and micro-hardness tests. The joint strength was evaluated by shear stress tests. The experiment was performed with varied length of pin probe 6, 7, and 8 mm, equal rotational speed of 2500 rpm, and welding speed (15 mm/minutes). The Inter-metallic compounds of aluminums sheet was cut off the pin probe and the mixture on the Carbon steel ST 37. Intermetallic compounds were analyzed on its micro sructure in this region aluminum and carbon steel mixed, the value joint tensile shear 6.2KN.
THE ROLE OF SHELL MOLD THICKNESS IN CONTROLLING SHRINKAGE POROSITY OF CAST AUTOMOTIVE PARTS Khoiruddin, Sukhoiri; Darmadi, Djarot B.; Wu, Ssu-Han
International Journal of Mechanical Engineering Technologies and Applications Vol. 7 No. 1 (2026): January - June
Publisher : Mechanical Engineering Department, Engineering Faculty, Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776//MECHTA.2026.007.01.4

Abstract

This study investigates the effect of shell mold thickness on shrinkage porosity observed through numerical simulation using a computer-aided engineering (CAE) approach and testing of mechanical, thermal, and physical properties of shell molds. This study investigated the thermal properties of different shell mold layer thicknesses. The results showed that the modulus of rupture (MOR) had a value of 6.66 MPa, the permeability was in the range of 1.8x10-¹² m² to 6.6x10-¹² m², and the heat transfer coefficient (HTC) had a value in the range of 900 W/m²-K to 660 W/m²-K. The CAE simulation shows that the initial coating thickness will cause problems in the thick corner area for automotive parts. To reduce the hot spot area is to increase the thickness of the mold shell to reduce the percentage of hot spots, which can reduce the possibility of shrinkage formation by 34%; that which occurs at a mold shell thickness of 6.5 layers can be reduced by about 24% compared to a shell thickness of 4.5 layers. In this study, the best solution to increase the productivity of investment casting is the selection of mold thickness, and therefore, objects that have high dimensions and accuracy must be correct in determining the use of shell mold thickness because different objects will certainly affect the defects that occur.
SUSTAINABLE CORROSION INHIBITION OF COPPER USING SANTOL (SANDORICUM KOETJAPE) FRUIT PEEL EXTRACT IN ACIDIC MEDIUM Ainunsyah, Zul; Gapsari , Femiana; Darmadi, Djarot B.; Sasmito, Muhammad
International Journal of Mechanical Engineering Technologies and Applications Vol. 7 No. 1 (2026): January - June
Publisher : Mechanical Engineering Department, Engineering Faculty, Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776//MECHTA.2026.007.01.9

Abstract

Corrosion control is crucial to material protection, particularly in industrial applications where metal degradation leads to significant economic losses. One of the major challenges in corrosion research is finding effective and eco-friendly inhibitors that can replace traditional toxic chemical inhibitors. This study explores the use of Santol (Sandoricum koetjape) fruit peel extract as a potential green inhibitor for copper corrosion in a 1 M HNO3 solution. Electrochemical techniques, including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), were used to evaluate the inhibition efficiency of the extract. The results showed a significant reduction in the corrosion rate, with an inhibition efficiency of 77.33% from PDP analysis and 97.50% from EIS measurements. The corrosion current density decreased from 1408.30 microA to 319.25 microA, and the charge transfer resistance increased from 22.56 Ohm to 902.88 Ohm. Santol fruit peel extract effectively inhibits copper corrosion, promoting the development of sustainable corrosion inhibitors and using agricultural waste as an alternative to conventional chemical inhibitors.
Co-Authors Agung Sugeng Widodo Ainunsyah, Zul Anindito Purnowidodo Ari Setiawan Bintang Rahmaddian Anwari, Bintang Rahmaddian Chan, Chien-Wei Eko Budianto EKO BUDIYANTO Fauzi, Katanda Fajar Gapsari , Femiana Halman, Halman Huang, Cheng-Fu Khoiruddin, Sukhoiri Lee , Sheng-Chan Mahatwan, Dian Moch. Agus Choiron Muhammad Ikram Kido Nasmi Herlina Sari Rudy Soenoko Sasmito, Muhammad Setiawan, Widia Sugiarto S Suteja Suteja, Suteja Teguh Dwi Widodo Utomo, Slamet Prasetyo Wahyono Suprapto Wu, Ssu-Han Yahya, Indra Nur Yudy Surya Irawan