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Journal : Metalurgi

Residual Stress Measurement of Used Mining Dump Truck Frame for Remanufacturing Purposes Ferdiyanto, David; Sofyan, Nofrijon; Yuwono, Akhmad Herman; Dhaneswara, Donanta
Metalurgi Vol 38, No 3 (2023): Metalurgi Vol. 38 No. 3 2023
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2023.730

Abstract

Remanufacturing the main frame of a mining dump truck can save cost, energy, and materials in heavy equipment industries. It also can reduce CO2 emissions for environmental preservation to achieve sustainability. However, since the mainframe received a dynamic load during operation, it presumably leaves accumulated residual stresses in the frame. The residual stress, particularly tensile residual stress, stands out as a primary contributing factor to the initiation of cracks, which may ultimately result in failures. In this paper, the residual stress of the used mining dump truck main frame was identified by modeling simulation using FEA (finite element analysis) and actual measurement using a portable x-ray residual stress analyzer with the cos α method. The results showed that the weld area subjected to dynamic loads exhibited the highest tensile residual stress, reaching approximately +772 MPa. This specific region emerges as a critical area demanding attention during the remanufacturing process. The application of PWHT (post-weld heat treatment) at 400 °C for 1 hour effectively reduced residual stress on the weld joint, predominantly tensile residual stress, by more than 80%.  
Effect of Heating Temperature and Die Insert Draft Angle on the Flowability of Hot Forged SCM435 Steel Sofyan, Nofrijon; Heruwiyono, Maulana; Yuwono, Akhmad Herman; Dhaneswara, Donanta
Metalurgi Vol 37, No 2 (2022): Metalurgi Vol. 37 No. 2 Agustus 2022
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (806.556 KB) | DOI: 10.14203/metalurgi.v37i2.635

Abstract

The problem of flowability in a closed forging process for heavy equipment industry is still widely found and this may affect the quality of the resulting product. To obtain the solution for this problem, in this work, the effect of heating temperature and die insert draft angle on the characteristic of hot forged SCM435 steel used for undercarriage track roller has been examined. The workpieces were heated at temperature variations of 1150 °C, 1200 °C, 1250 °C and were hot forged at die insert draft angles of 3°, 5°, and 7° to form undercarriage track roller products. The mechanical properties of the products were characterized through hardness and dimension examination, whereas the microstructure was characterized using an optical microscope. The results showed that increasing the heating temperature and die insert draft angle resulted in good flowability. The best result was obtained from the heating temperature of 1250 °C at the die insert draft angle of 7°, with diameter and height of 191.2 mm and 53.6 mm, respectively. This characteristic of the obtained hot-forged product agreed with that of the specified forging design for the undercarriage track roller
Synthesis of Tin Oxide Nanocrystallites with Various Calcination Temperatures Using Co-Precipitation Method with Local Tin Chloride Precursor Panthoko, Norbert Egan Christo; Septiningrum, Fairuz; Yuwono, Akhmad Herman; Nurhidayah, Eka; Maulana, Fakhri Akbar; Sofyan, Nofrijon; Dhaneswara, Donanta; Lalasari, Latifa Hanum; Arini, Tri; Andriyah, Lia; Firdiyono, Florentinus; Ardianto, Yahya Winda; Pawan, Ria Wardhani
Metalurgi Vol 38, No 1 (2023): Metalurgi Vol. 38 No. 1 2023
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (723.013 KB) | DOI: 10.55981/metalurgi.2023.687

Abstract

Indonesia is one of the largest tin metal producers in the world, and one of its derivative products is tin chloride (SnCl4). This material has been used as a raw ingredient for the production of organotin compounds such as methyltin mercaptide for PVC (polyvinyl chloride) plastic industry as a heat stabilizer. On the other hand, this precursor can be used to synthesize SnO2 nanomaterials, which have other strategic potentials, including photocatalysts and solar cell applications. In this study, the synthesis of SnO2 nanocrystallites was carried out using a local tin chloride precursor via the co-precipitation method, followed by a calcination process at temperatures of 300, 400, 500, and 600 °C, for further usage as an ETL (electron transport layer) in a PSC (perovskite solar cell) device. The basic properties characterization was carried out using XRD (X-ray diffraction), ultraviolet-visible (UV-Vis) spectroscopy, and SEM (scanning electron microscopy), while the photocurrent-voltage (I-V) curve photovoltaic performance of the device was performed using a semiconductor parameter analyzer. The characterization results showed that increasing the calcination temperature from 300 to 600 °C increased the average crystallite size from 1.19 to 13.75 nm and decreased the band gap energy from 3.57 to 3.10 eV. The highest PCE (power conversion efficiency) was obtained from the device fabricated with SnO2 nanocrystallites calcined at a temperature of 300 °C, which was 0.0024%. This result was obtained due to the highest transmittance of this sample as compared to others; the higher the transmittance, the better the performance of the ETL, which in turn increased the overall efficiency of the PSC