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All Journal Jurnal Teknik Industri Prosiding Seminar Nasional Sains Dan Teknologi Fakultas Teknik Journal of Applied Sciences, Management and Engineering Technology (JASMET)
Rochman Rochiem
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Civil Engineering, Building, Construction & Architecture Computer Science & IT Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology

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Synthesis Of Nanoparticle Barium Hex Aferrite By Sol Gel Auto Combutio W Widyastuti; Felly Yulian FF; Rochman Rochiem; Hariyati Purwaningsih
Jurnal Teknik Industri Vol. 12 No. 2 (2011): Agustus
Publisher : Department Industrial Engineering, University of Muhammadiyah Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3424.509 KB) | DOI: 10.22219/JTIUMM.Vol12.No2.156-161

Abstract

Nanocrystalline of Barium Hexaferrite (BaFe12O19) powders have been synthesized using the sol gel auto combustion method. The ferrite precursors were obtained from aqueous mixtures of Barium nitrate and Ferric nitrate by auto combustion reaction from gel point. These precursors were sintered at different temperatures ranging from 700 to 1000oC for constant calcinations time 2,5 h in a static air atmosphere. Effects of Fe3+/Ba2+ mol ratios and sintering temperatures on the microstructure and magnetic properties were systematically studied. The powders formed were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and VSM. The results obtained showed that the phase BaFe12O19 powders were achieved by the Fe3+/Ba2+ mole ratio from the stoichiometric value 11, 11.5 and 12 at temperature 950OC. With increasing of temperature sintering, coercivity and magnetization value tends to rising. The maximum saturation magnetization (66.16 emu/g) was achieved at the Fe3+/Ba2+ mole ratio to 11.5 and the sintering temperature 950OC. The maximum coercivity value 3542 Oe achieved at mole ratio sample 12 with sintering temperature 950OC. Maximum saturation 6616 emu/g achieved at mole ratio sample 115 with the same temperature.
PENGARUH JARAK NOZZLE PADA PROSES COATING FeCrBMnSi DENGAN METODE WIRE ARC SPRAY TERHADAP KETAHANAN THERMAL Suswanto Suswanto; Muhammad Suchaimi; Hariyati Purwaningsih; Rochman Rochiem; Budi Agung Kurniawan
Prosiding SNST Fakultas Teknik Vol 1, No 1 (2017): PROSIDING SEMINAR NASIONAL SAINS DAN TEKNOLOGI 8 2017
Publisher : Prosiding SNST Fakultas Teknik

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (421.671 KB)

Abstract

Turbin uap adalah alat yang sering digunakan di bidang industri maupun sebagai pembangkit listrik. Turbin uap bekerja pada temperature tinggi sehingga kerusakan yang terjadi biasanya disebabkan oleh korosi temperatur tinggi (KTT) atau hot corrossion. LTHC (Low temperature Hot Corrosion) adalah salah satu jenis KTT yang terjadi pada temperatur 700-800OC. Korosi jenis ini terjadi pada sudu-sudu turbin uap yang menyebabkan material pada turbin mengalami kerusakan dan penurunan fungsi. Salah satu metode yang digunakan untuk melindungi material pada sudu-sudu turbin adalah proses coating dengan metode wire arc spray. Penelitian ini bertujuan untuk menganalisis pengaruh jarak nozzle pada proses coating FeCrBMnSi dengan metode wire arc spray terhadap ketahanan thermal. Penelitian ini diawali dengan proses preparasi spesimen yang kemudian dilakukan proses pengujian yaitu SEM, XRD, dan thermal cycle. Dari hasil penelitian ini, didapatkan hasil terbaik yaitu pada jarak 400 mm dan yang mempunyai kekuatan lekat sebesar 22,58 MPa. Dari pengujian thermal cycle didapatkan senyawa precipitate boride (Fe9B)0,2 yang mengakibatkan peningkatan nilai kekerasan permukaan. Selain itu pada permukaan coating terbentuk senyawa oksida berupa Fe3O4 yang mengakibatkan perambatan retak.Kata kunci: coating, FeCrBMnSi, jarak nozzle, ketahanan thermal, wire arc spray  
The Effect of Annealing Temperature and Quenching Media Variations On Heat Treatment Process of Cu-Zn-Al Shape Memory Alloys For Shape Memory Effect and Microstructure Mavindra Ramadhani; Rochman Rochiem; Rizki Rizki; M Arfani
Journal of Applied Sciences, Management and Engineering Technology Vol 4, No 1 (2023)
Publisher : Institut Teknologi Adhi Tama Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31284/j.jasmet.2023.v4i1.4486

Abstract

Shape Memory Alloys (SMA) is a material that can return to its original shape after undergoing mechanical deformation. The most commonly SMA material used is the Ni-Ti alloy. However, it is high cost. So that it is necessary to have alternative materials, for instance Cu-Zn-Al. Several studies related to Cu-Zn-Al Shape Memory Alloys have poor mechanical properties. So there further research required in order to determine the heat treatment process of Cu-Zn-Al Shape Memory Alloys. In this study Cu-21Zn-5Al alloys were given heat treatment with annealing temperature variations (425;550;600°C) and cooling media (brine, dry ice). Annealing process affects the mechanical properties and microstructure of the test material. Cooling media results the cooling rate during solution treatment. Tests in this study include hardness test, metallographic test, XRD test, DSC test, and SME test. From the test results, it was found that all the test variables have the Shape Memory Effect. The variable that had the greatest recovery (38.3%) was annealing temperature of 450°C with the cooling solution media using brine. In addition, the most rapid cooling occurs in the brine cooling media.
Analysis of the Effect of Electrode Variation and Current on the Welding Results of Corten A Steel using SMAW Method on Microstructure, Corrosion Resistance, and Mechanical Properties Mavindra Ramadhani; Rochman Rochiem; Muhammad Irsyad Zain
Journal of Applied Sciences, Management and Engineering Technology Vol 4, No 1 (2023)
Publisher : Institut Teknologi Adhi Tama Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31284/j.jasmet.2023.v4i1.4488

Abstract

The emission exhaust stack in industries must have good corrosion resistance and heat resistance in both the base metal and the welded joints. Therefore, corten steel is chosen as the base metal for the exhaust stack due to its excellent corrosion resistance and heat resistance, as well as its costeffectiveness compared to other heat-resistant steels. This study aims to analyze the welded joints of corten steel in terms of microstructure, corrosion resistance, and tensile strength using the Shielded Metal Arc Welding (SMAW) method, following the Welding Procedure Specification (WPS). The variables used in this study are the electrode variations using E7016-G and E8016-G electrodes, and the current variations of 90, 105, and 120 A. The results of this study indicate that in the metallography testing, the highest percentage of the perlitic phase is found in specimen B2, which uses the E8016-G electrode and a current of 105A, reaching 41.92% in the weld metal and 29.6% in the Heat-Affected Zone (HAZ). In the corrosion resistance testing, the corrosion rate fluctuates within the 3-hour and 6-hour time ranges, but decreases within the 10-hour time range. The lowest corrosion rate is observed in specimen B2 using the E8016-G electrode and a current of 105A. In terms of mechanical properties, the best results are obtained from the tensile testing and hardness testing of specimen B2 using the E8016-G electrode and a current of 105A.
Co-Authors Felly Yulian FF Hariyati Purwaningsih M Arfani Mavindra Ramadhani Muhammad Irsyad Zain Muhammad Suchaimi Rizki Rizki Suswanto Suswanto W Widyastuti