Micropowders of oxide-dispersion-strengthened (ODS) steel have been synthesized using the ultrasonic irradiation method with variations in amplitude. The ultrasonic irradiation process is performed for 50 h at a frequency of 20 kHz with 40%, 50%, and 60% amplitudes in toluene solution. The formation of Fe-Cr microalloys in the preparation of Fe-15Cr-0.5Y 2 O 3 powder was analyzed using SEM-EDS, X-ray diffraction (XRD), and TEM-EDS. The percentage of Fe-Cr phase mass fraction of ODS steel micropowder formed during ultrasonic irradiation with 40%:50%:60% amplitude was 12.2%:34.1%:22.1%, with 25.67:77.02:38.51 nm crystallite size. The crystallite size at 50% amplitude was the largest, and the diffusion process of Fe-Cr-Y 2 O 3 microparticles was most dominant at 50% amplitude. The Fe and Cr phases are still present when the ODS particles successfully dispersed in the main particle. AbstrakSintesis Baru Paduan Mikro Baja ODS dengan Irradiasi Ultrasonik Amplitudo Tinggi. Serbuk mikro dari baja yang diperkuat dengan dispersi oksida (ODS) telah disintesis menggunakan metode iradiasi ultrasonik dengan variasi amplitudo. Proses iradiasi ultrasonik dilakukan selama 50 jam pada frekuensi 20 kHz dengan amplitudo 40%, 50%, dan 60% dalam larutan toluena. Pembentukan paduan mikro Fe-Cr dalam preparasi serbuk Fe-15Cr-0.5Y2O3 dianalisis menggunakan SEM-EDS (scanning electron microscopy-energy-dispersive spectroscopy), difraksi sinar-X (XRD), dan TEM-EDS (transmission electron microscopy-energy-dispersive spectroscopy).

Synthesis and Monte Carlo simulation of improved concrete composites as x-ray/gamma ray shielding materials were performed. Samples of shieldings were synthesized using the base materials of Portland-type cement concrete with fillers of alloy steel, Co, Mn, and Cr, mixed separately as additives. The samples were characterized using Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry (SEM-EDS) to determine the constituent elements quantitatively. Linear attenuation coefficients of the samples were measured in the experiments and also simulated using Monte Carlo transport code MCNP5 in order to evaluate their shielding performance. The results of the experimentation and computer simulation reveal concrete with alloy steel added as having the best shielding properties, although concrete with other fillers added also exhibited enhanced shielding performance. It was demonstrated that 6.06 w% of fillers enhanced the x-ray/gamma ray shielding capability of ordinary concrete composites by improving their attenuation coefficient values by 40-60%.

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