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Abstrak :
ABSTRAK
Percampuran serbuk baja ODS Oxide Dispersion Strengthened pada umumnya menggunakan metode mekanik dengan ball mill, namun selama pembuatannya disertai pembentukan oksida. Percampuran serbuk dengan metode iradiasi ultrasonik merupakan metode baru yang memberikan keuntungan berupa membentuk microalloying partikel dan meminimalisasi pembentukan fasa oksida. Penelitian ini mempelajari tentang pengaruh amplitudo 20, 30, 40 dan waktu perlakuan 20jam, 30 jam terhadap reduksi ukuran partikel dan pembentukan microalloying Fe-Cr. Serbuk dibagi menjadi 7 sampel dengan sampel A perlakuan pencampuran mortar, iradiasi ultrasonik sampel B1 A:20, t: 20 jam, sampel B2 A:30, t:20 jam, sampel B3 A:40, t:20 jam, sampel C1 A:20, t:30 jam, sampel C2 A:40, t:30 jam, dan sampel C3 A:40, t:30 jam yang kemudian dikarakterisasi menggunakan SEM, EDS, dan XRD. Hasil penelitian ini adalah pada iradiasi ultrasonik selama 20 jam menghasilkan ukuran partikel sampel B1>sampel B2>sampel B3 adalah 5.326 m>4.769 m>4.563 m. Sedangkan pada iradiasi ultrasonik selama 30 jam menghasilkan ukuran partikel sampel C1>sampel C2>sampel C3 adalah 4.605 m>3.719 m>3.608 m. Komposisi Fe-Cr yang terbentuk adalah sampel A: sampel B1: sampel B2: sampel B3:sampel C1:sampel C2: C3 adalah 0:48.85:26.07:2478:89:81.94:42.98. Hasil tersebut menunjukan bahwa semakin besar amplitudo, microalloying Fe-Cr yang terbentuk menjadi semakin rendah, penambahan waktu perlakuan justru meningkatkan presentase Fe-Cr yang terbentuk. Pada ultrasonik selama 20 jam, nilai crystallite size Fe-Cr sampel B1>sampel B2>sampel B3 adalah 292.72 nm>246.76 nm>184.77 nm dan nilai microstrains Fe-Cr sampel B1184.34 nm dan nilai microstrains Fe-Cr sampel C1< sampel C2.

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ABSTRACT
The mixing of ODS Oxide Dispersion Strengthened powder generally uses mechanical method with ball mill, but during its manufacture with oxide formation. Powder mixing with ultrasonic irradiation method is a new method that provides the advantage of forming microalloying particles and minimizing the formation of the oxide phase. This study studied the effect of amplitude 20, 30, 40 and treatment time 20h, 30h on particle size reduction and formation of Fe Cr microalloying. The powder was divided into 7 samples with sample A mortar mixing treatment, ultrasonic irradiation of sample B1 A 20, t 20 hours, sample B2 A 30, t 20 hours, sample B3 A 40, T 20 hours, sample C1 A 20, t 30 hours, C2 sample A 40, t 30 hours, and C3 sample A 40, t 30 hours Which is then characterized using SEM, EDS, and XRD. The results of this study were on ultrasonic irradiation for 20 hours yielding sample particle size B1 sample B2 B3 sample was 5,326 m 4,769 m 4,563 m. While on ultrasonic irradiation for 30 hours resulted in particle size of sample C1 C2 sample C3 sample is 4,605 m 3,719 m 3,608 m. The composition of Fe Cr formed is sample A sample B1 sample B2 sample B3 sample C1 sample C2 C3 is 0 48.85 26.07 24.78 89 81.94 42.98. These results show that the greater the amplitude, the lower the Fe Cr microalloying that is formed, the added time of treatment actually increases the Fe Cr percentage that is formed. At ultrasonic for 20 hours, the crystallite size of Fe Cr sample B1 sample B2 B3 sample is 292.72 nm 246.76 nm 184.77 nm and the Fe Cr microstrains value of sample B1 198.02 nm 184.34 nm and the Fe Cr microstrains value of sample C1.

Abstrak :
ABSTRAK
Baja ODS (Oxide Dispersion Strengthened) merupakan paduan dengan ketahanan temperatur dan korosi yang baik. Penggunaan metode iradiasi ultrasonik di dalam larutan toluene merupakan metode baru yang dapat memberikan keuntungan berupa ukuran butir yang halus, dapat membentuk microalloying di dalam serbuk, dan dapat meminimalisasi pembentukan fasa oksida. Penelitian ini mempelajari tentang pengaruh amplitudo terhadap reduksi ukuran partikel, homogenitas serbuk, dan pembentukan microalloying Fe-Cr pada preparasi serbuk Fe-15Cr-0.5Y2O3. Serbuk dibagi menjadi 4 sampel dengan perlakuan pencampuran mortar (sampel A), iradiasi ultrasonik dengan amplitudo 40% (sampel B), 50% (sampel C), dan 60% (sampel D) yang kemudian dikarakterisasi menggunakan SEM, EDS, dan XRD. Hasil dari penelitian ini adalah peningkatan amplitudo akan menurunkan ukuran butir dengan nilai sampel B>sampel C>sampel D adalah 4.63 μm>3.44 μm>3.09 μm. Sampel C menghasilkan partikel Fe-Cr sementara sampel B dan D terbentuk partikel paduan Fe-Cr-Y2O3. Nilai komposisi Fe-Cr terbesar dicapai pada amplitudo 40% dengan nilai sampel A:sampel B:sampel C: sampel D adalah 0.00%:20.5%:10.06%:5.2% tanpa pembentukan oksida dengan ukuran crystallite Fe-Cr sampel B:sampel C:sampel D berukuran 16.79 nm:30.13 nm: 55.69 nm. Nilai lattice strain sampel B:sampel C: sampel D adalah 0.0055:0.0030:0.0016.

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ABSTRACT
ODS Steel (Oxide Dispersion Strengthened) is an alloy with good corrosion and high temperature resistance. The utilization of ultrasonic irradiation method in toluene solution is a new method giving benefits like producing fine grain-size, forming micro-alloying on powder, and minimizing the oxide phase formation. This research investigates the influence of amplitude on the reduction of the particle size, the homogeneity of the powder, and the formation of Fe-Cr microalloying on Fe-15Cr-0.5Y2O3 powder preparation. The powder was divided into 4 samples with various treatments such as mortar mixing (sample A) and ultrasonic irradiation with an amplitude of 40% (sample B), 50% (sample C) and 60% (sample D). After that, each sample was characterized by SEM, EDS and XRD. This research shows that increasing the amplitude will decrease the grain size with the value of sample B> sample C> sample D is 4.63 μm>μm 3:44> 3:09 μm. Sample C produced Fe-Cr particles meanwhile samples B and D formed Fe-Cr-Y2O3 alloy particle. The highest composition value of Fe-Cr is reached on the amplitude of 40% to the composition value of sample A: sample B: sample C: sample D is 0.00%: 20.5%: 10:06%: 5.2% without the oxide formation. The size of crystalline Fe-Cr sample B: sample C : sample D size of 16.79 nm: 30.13 nm: 55.69 nm. The lattice strain value of the sample B: the sample C: sample D was 0.0055: 0.0030: 0.0016. ;

Abstrak :
[Baja digunakan sebagai material penyusun pada badan pelindung kendaran taktis karena ketahanan balistiknya yang baik. Tetapi, densitasnya yang tinggi memicu dilakukannya penelitian material pengganti, salah satu alternatifnya adalah komposit aluminium dengan penguat ZrO2. Pada penelitian penulis sebelumnya, tiga lapis pelat komposit Al-13,1Zn-6,1Mg-6,7Si-1,4Cu – 7.5 vol.% ZrO2 dengan tebal masing-masing pelat 10 mm terbukti mampu untuk menahan penetrasi peluru pada pengujian balistik tipe III. Pada penelitian ini, dibuat komposit pelat tebal dengan ketebalan 25 mm dengan matriks Al-9Zn-6Mg-3Si berpenguat 5 vol.% ZrO2 dan variasi penambahan paduan mikro berupa 0,001 wt.% Sr, 0,1 wt.% Ti, dan 2 wt.% Cr yang difabrikasi melalui metode squeeze casting. Untuk meningkatkan sifat mekanis, dilakukan laku pelarutan pada temperatur 450 oC selama 1 jam yang dilanjutkan dengan laku penuaan pada temperatur 200 oC selama 1 jam. Beberapa karakterisasi yang dilakukan adalah pengujian komposisi kimia menggunakan Optical Emission Spectrometer (OES), analisis struktur mikro dengan mikroskop optik (OM), Scanning Elecron Microscopy (SEM), dan Energy Dispersive X-Rays (EDX), perhitungan persentase porositas menggunakan perangkat lunak ImageJ, pengujian kekerasan Rockwell B, serta pengujian impak metode charpy. Pengujian balistik tipe III dilakukan pada pelat komposit setelah diberi perlakuan permukaan berupa thermal spray High Velocity Oxygen-Fuel (HVOF) menggunakan material pelapis 88WC-12Co dengan ketebalan ±200 μm. Hasil penelitian menunjukkan bahwa nilai kekerasan yang paling tinggi dimiliki oleh pelat komposit dengan paduan mikro Cr, yaitu mencapai 77,75 HRB. Pelat komposit dengan paduan mikro Ti memiliki harga impak yang paling tinggi yaitu mencapai 15,77 x 10-3 J/mm2. Seluruh pelat komposit memiliki nilai kekerasan yang relatif rendah bila dibandingkan dengan kekerasan teoritisnya, yang terjadi akibat proses fabrikasi yang tidak sempurna. Partikel ZrO2 yang ditambahkan pada lelehan paduan aluminium bereaksi sehingga membentuk Al3Zr yang ditemukan dalam jumlah yang banyak di dalam mikrostruktur komposit. Pada hasil pengujian balistik, pelat komposit Sr memiliki karakteristik balistik yang paling baik, yang terlihat dari jejak peluru pada bagian depan pelat dan diameter terperforasi pada bagian belakang pelat yang relatif kecil. Karakteristik balistik yang relatif baik ini didapatkan dari kombinasi nilai kekerasan dan harga impaknya yang relatif tinggi, yaitu 62,6 HRB dan 14,65 x 10-3 J/mm2 secara berurutan.;Steel has been used as the constituent material of tactical vehicle’s body due to its high ballistic resistance. But, steel has high density that triggered research for material substitution. One alternative is aluminium composite that reinforced by ZrO2. Previous research has shown that three plies of Al-13.1Zn-6.1Mg-6.7Si-1.4Cu – 7.5 vol.% ZrO2 composite, each with the thickness of 10 mm, could withstand bullet penetration on type III ballistic testing. In this research, Al-9Zn-6Mg-3Si composite thick plates of 25 mm reinforced by 5 vol.% ZrO2 with the variation of 0.001 wt.% Sr, 0.1 wt.% Ti, and 2 wt.% Cr microalloying are fabricated by squeeze casting method. To improve the mechanical properties, the composite plates were solution treated at 450 oC for 1 hour then aged at 200 oC for 1 hour. The characterizations are consisted of chemical composition testing by using Optical Emission Spectrometer (OES), microtructure analysis by using Optical Microscope (OM), Scanning Elecron Microscopy (SEM), and Energy Dispersive X-Rays (EDX), porosity calculation by using ImageJ software, hardness testing by using Rockwell B, and impact testing by using charpy method. Type III ballistic testing was conducted on the composite plates after High Velocity Oxygen-Fuel (HVOF) thermal spray with 88WC-12Co of ±200 μm thickness. The results showed that the highest hardness was owned by the Cr-added composite plate with the value of 77.75 HRB. The Ti-added composite plate had the highest impact value of 15.77 x 10-3 J/mm2. The hardness of all composite plates was relatively low compared to the theoritical hardness, which was due to imperfect fabrication process. The ZrO2 particles added to the molten aluminium alloy reacted to form Al3Zr, which was found in a considerable amount in the microstructure. From the ballistic testing, Sr composite plate was found to have the best ballistic characteristic compared to the other three, which was shown by small trace of bullet on the front part of the plate, and also small perforated diameter on the back part of the plate. This relatively good ballistic characteristic was believed to be due to combination of high hardness and impact values, with the value of 62.6 HRB and 14.65 x 10-3 J/mm2, respectively., Steel has been used as the constituent material of tactical vehicle’s body due to its high ballistic resistance. But, steel has high density that triggered research for material substitution. One alternative is aluminium composite that reinforced by ZrO2. Previous research has shown that three plies of Al-13.1Zn-6.1Mg-6.7Si-1.4Cu – 7.5 vol.% ZrO2 composite, each with the thickness of 10 mm, could withstand bullet penetration on type III ballistic testing. In this research, Al-9Zn-6Mg-3Si composite thick plates of 25 mm reinforced by 5 vol.% ZrO2 with the variation of 0.001 wt.% Sr, 0.1 wt.% Ti, and 2 wt.% Cr microalloying are fabricated by squeeze casting method. To improve the mechanical properties, the composite plates were solution treated at 450 oC for 1 hour then aged at 200 oC for 1 hour. The characterizations are consisted of chemical composition testing by using Optical Emission Spectrometer (OES), microtructure analysis by using Optical Microscope (OM), Scanning Elecron Microscopy (SEM), and Energy Dispersive X-Rays (EDX), porosity calculation by using ImageJ software, hardness testing by using Rockwell B, and impact testing by using charpy method. Type III ballistic testing was conducted on the composite plates after High Velocity Oxygen-Fuel (HVOF) thermal spray with 88WC-12Co of ±200 μm thickness. The results showed that the highest hardness was owned by the Cr-added composite plate with the value of 77.75 HRB. The Ti-added composite plate had the highest impact value of 15.77 x 10-3 J/mm2. The hardness of all composite plates was relatively low compared to the theoritical hardness, which was due to imperfect fabrication process. The ZrO2 particles added to the molten aluminium alloy reacted to form Al3Zr, which was found in a considerable amount in the microstructure. From the ballistic testing, Sr composite plate was found to have the best ballistic characteristic compared to the other three, which was shown by small trace of bullet on the front part of the plate, and also small perforated diameter on the back part of the plate. This relatively good ballistic characteristic was believed to be due to combination of high hardness and impact values, with the value of 62.6 HRB and 14.65 x 10-3 J/mm2, respectively.]