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Martinez, C., Briones, F., Aguilar, C., Araya, N., Iturriza, I., Machado, I., et al. (2020). Effect of hot pressing and hot isostatic pressing on the microstructure, hardness, and wear behavior of nickel. Mater. Lett., 273, 127944.
Abstract: Nanocrystalline Ni (Ni-nc) obtained by mechanical milling may present improved mechanical properties paired with high abrasion resistance. Different sintering processes were used to consolidate Nanocrystaline Ni: hot pressed (HP) and hot-isostatic pressed (HIP). The microstructure, mechanical properties, and tribological were evaluated to compare the processes. X-ray diffraction patterns showed that HIP-consolidated specimens had larger crystallite sizes and 37% less microstrain when compared to the HP specimens. The nanohardness of the HIP specimens was also carried out and it was 50% lower than that of HP specimens, whereas its coefficient of friction found was 25% higher. These results show the advantages of the HP process over the HIP since the high pressure. The low sintering temperature of HP inhibited the grain growth, which leads excellent mechanical and tribological properties of Ni. (C) 2020 Elsevier B.V. All rights reserved.
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Martinez, C., Briones, F., Rojas, P., Aguilar, C., Guzman, D., & Ordonez, S. (2017). Microstructural and mechanical characterization of copper, nickel, and Cu-based alloys obtained by mechanical alloying and hot pressing. Mater. Lett., 209, 509–512.
Abstract: Mechanical alloying and uniaxial compaction were used to obtain configurations of: elemental powders of Cu and Ni; binary alloys (Cu-Ni and Cu-Zr); and a ternary alloy (Cu-Ni-Zr) under the same mechanical milling and hot pressing conditions. Microstructure and mechanical properties of these were investigated. According to XRD results, hot pressing process increases crystallite size and decreases microstrain in the compact samples, due to the release of crystalline defects without crystallization of amorphous alloys. The milled powder samples have a higher hardness than the unmilled samples, since crystal defects are incorporated into microstructural refinement during milling. The ternary alloy Cu-40Ni-10Zr had the highest hardness of all systems studied, reaching 689 HV0.5. Compression tests at 5% strain determined that Zr-containing samples (amorphous phase) become more fragile after processing, and have the lowest values of compressive strength. In contrast, Ni samples and Cu-Ni binary alloys are more resistant to compression. (
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Nandhakumar, E., Selvakumar, P., Arulraj, A., Vivek, E., Venkatraman, M. R., Sasikumar, A., et al. (2023). Investigation on rod like SnO2@CdCO3 nanocomposite-based electron transport layer for CsPbBr3 heterojunction perovskite solar cell applications br. Mater. Lett., 330, 133396.
Abstract: A novel carbonate-based nanocomposite synthesized by hydrothermal technique for planar perovskite solar cells (PPSCs) applications. According to this study, SnO2@CdCO3and SnO2/SnO2@CdCO3 performs as dual electron transporting layers for CsPbBr3 based perovskite solar cell. The fabricated PSCs with architecture of FTO/SnO2/ SnO2@CdCO3/CsPbBr3/C showed a Voc of 0.84 V, Jsc of 12.30 mA cmi 2, PCE of 6.67 % and FF of 0.64 are obtained at ambient condition.
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Shanmugaraj, K., Mangalaraja, R. V., Campos, C. H., Singh, D. P., Udayabhaskar, R., Bedoya, S., et al. (2023). Platinum nanoparticles confined within TiO2 nanotube matrix for enhanced catalytic reduction of azure b dye. Mater. Lett., 330, 133208.
Abstract: In this work, we report the synthesis of TiO2 nanotubes encapsulated platinum nanoparticles (PtNPs-TiO2NTs) as a highly efficient catalyst for the catalytic reduction of azure B (AZB) dye in the sodium borohydride (NaBH4) medium. The encapsulation of PtNPs (particle size similar to 2-3 nm) inside the TiO2NTs was confirmed by HR-TEM analysis. The as-prepared PtNPs-TiO2NTs exhibit higher conversion efficiency than 99 % with a pseudo-first order rate constant of 2.6 x 10(-3) s(-1). Owing to the confinement effect of PtNPs inside the TiO2NTs, the synthesized catalyst shows the superior operative stability even after 8 consecutive recycles without any loss in its activity. This work opens up new avenue for the designing of confined catalyst for various industrial catalytic reactions.
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