Hadfield steel, under unit pressure conditions, strengthens itself by forming a high density dislocation structure, which results in increased resistance to dynamic impact wear. However, under abrasion conditions, the homogeneous microstructure of the cast steel is insufficient to achieve the expected service life. The aim of the research is to conduct a comparative analysis of the material in its as-delivered state and after two-stage heat treatment (isothermal annealing followed by re-austenitisation). It was found that after isothermal annealing of X120Mn12 grade steel at a temperature of 510 °C, a microstructure with a complex morphology consisting of colonies of fine-grained pearlite, (Fe,Mn)C carbides distributed along the grain boundaries of the former austenite and needle-like (Fe,Mn)C carbides was obtained in the austenite matrix. The subsequent thermal treatment of the steel with the use of supersaturating annealing at 900 °C resulted in a heterogeneous microstructure consisting of evenly distributed globular carbide precipitations in a matrix of considerably finer austenite grains in comparison with the as-delivered original state. As a result of the final microstructural changes achieved, a 16.4% increase in abrasion resistance was obtained compared to the delivered condition.
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http://dx.doi.org/10.3390/ma15072622 | DOI Listing |
Materials (Basel)
December 2024
Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Krakow, Poland.
The resistivity of the silica SBA-15 type can be significantly improved by forming a thin layer of carbon on the pore surface. This is possible through the carbonization reaction of a surfactant used as a structure-directing agent in the synthesis of mesostructured silica materials. The synthesis of this type of silica-carbon composite (SBA-C) is based on the use of sulfuric acid to create a carbon layer from surfactant molecules encapsulated in silica mesopores.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
We developed a rapid and sensitive diagnostic platform that integrates isothermal viral gene amplification with a nucleic acid lateral flow assay (NALFA) to detect SARS-CoV-2 RNA. Isothermal gene amplification was performed by combining reverse transcription of viral RNA with recombinase polymerase amplification (RPA). In our diagnostic platform, DNA primers for the RPA reaction were modified by appending DNA tails, enabling the synthesis of tailed amplicon DNAs.
View Article and Find Full Text PDFSci Rep
December 2024
Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-Universität Bochum, Universitätsstr. 150, 44801, Bochum, NRW, Germany.
The present research explores theoretical and computational aspects of the morphological instability of Kirkendall voids induced by a directed flux of vacancies. A quantitative phase-field model is coupled with a multi-component diffusion model and CALPHAD-type thermodynamic and kinetic databases to obtain a meso-scale description of Kirkendall void morphologies under isothermal annealing. The material under investigation is a diffusion couple consisting of a multi-phase multi-component single-crystal Ni-based superalloy on one side and pure Ni on the other side.
View Article and Find Full Text PDFSoft Matter
January 2025
National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
This study explores the concurrent formation of surface perforations, parallel cylinders, and double gyroids in symmetric PS--PMMA/hPS blend films during isothermal annealing at 205 and 240 °C. By controlling the weight fraction ratio of PS--PMMA to hPS at 75/25, we systematically examined the impact of film thickness and annealing temperature on nanodomain development. Using GISAXS and SEM, we observed that thin films rapidly formed surface perforations and underlying parallel cylinders at both annealing temperatures.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA.
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