L1_(2)-strengthened high-entropy alloys(HEAs)are promising materials for advanced structural applications in harsh environments due to their outstanding mechanical properties.However,the Cr-depleted L1_(2)par-ticles u...L1_(2)-strengthened high-entropy alloys(HEAs)are promising materials for advanced structural applications in harsh environments due to their outstanding mechanical properties.However,the Cr-depleted L1_(2)par-ticles usually increase the alloy’s galvanic corrosion susceptibility,thus resulting in a decrease in pit-ting resistance.In this work,the corrosion behavior and associated passive film characteristics of a novel Co_(40)Cr_(20)Ni_(30)Al_(5)Ti_(5)HEA(at.%)additively manufactured by selective laser melting(SLM)were systemat-ically characterized and investigated.It was found that the precipitation of coherent nano-lamellar L1_(2)phase significantly refined the grain structure of the aged alloy,which leads to an anomalously improved corrosion resistance compared to the as-printed single-phase counterpart.Such excellent corrosion resis-tance of the aged alloy originated from the thin amorphous passive film with Cr_(2)O_(3),Al_(2)O_(3),and TiO_(2)as the main constituents that were firmly adhered to the alloy matrix.Moreover,the corrosion morphologies revealed that the dense and large-sized pits on the as-printed alloy were in sharp contrast to the sparse and irregularly-shaped pits on the aged alloy,which can be attributed to the potential difference and/or the refined grain structure.These findings will effectively advance the development of corrosion-resistant additively manufactured alloys and provide new insights into the innovative design of high-performance damage-tolerant L1_(2)-strengthened HEAs.展开更多
The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to meas...The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to measure the separate electron and positron spectra,as well as the positron fraction.In this study,the Earth's magnetic field is used to distinguish CR electrons and positrons,as the DAMPE detector does not carry an onboard magnet.The energy for the measurements ranges from 10 to 20 GeV,which is currently limited at high energy by the zenith-pointing orientation of DAMPE.The results are consistent with previous measurements based on the magnetic spectrometer by AMS-02 and PAMELA,whereas the results of Fermi-LAT appear to be systematically shifted to larger values.展开更多
基金financial support from the Na-tional Natural Science Foundation of China(Grant Nos.52222112 and 52101135)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011220)+2 种基金the Research Grants Council of the Hong Kong Special Administrative Region,China(Grant No.CityU 11208823)the International Cooperation and Innovation Fund(Grant No.KZ8F231907)The APT research was conducted at the Inter-University 3D APT Unit of City University of Hong Kong(CityU),which is supported by the CityU grant 9360161.
文摘L1_(2)-strengthened high-entropy alloys(HEAs)are promising materials for advanced structural applications in harsh environments due to their outstanding mechanical properties.However,the Cr-depleted L1_(2)par-ticles usually increase the alloy’s galvanic corrosion susceptibility,thus resulting in a decrease in pit-ting resistance.In this work,the corrosion behavior and associated passive film characteristics of a novel Co_(40)Cr_(20)Ni_(30)Al_(5)Ti_(5)HEA(at.%)additively manufactured by selective laser melting(SLM)were systemat-ically characterized and investigated.It was found that the precipitation of coherent nano-lamellar L1_(2)phase significantly refined the grain structure of the aged alloy,which leads to an anomalously improved corrosion resistance compared to the as-printed single-phase counterpart.Such excellent corrosion resis-tance of the aged alloy originated from the thin amorphous passive film with Cr_(2)O_(3),Al_(2)O_(3),and TiO_(2)as the main constituents that were firmly adhered to the alloy matrix.Moreover,the corrosion morphologies revealed that the dense and large-sized pits on the as-printed alloy were in sharp contrast to the sparse and irregularly-shaped pits on the aged alloy,which can be attributed to the potential difference and/or the refined grain structure.These findings will effectively advance the development of corrosion-resistant additively manufactured alloys and provide new insights into the innovative design of high-performance damage-tolerant L1_(2)-strengthened HEAs.
基金supported by the National Key Research and Development Program of China(No.2022YFF0503303)the National Natural Science Foundation of China(Nos.12220101003,12275266,12003076,12022503,12103094 and U2031149)+8 种基金Outstanding Youth Science Foundation of NSFC(No.12022503)the Project for Young Scientists in Basic Research of the Chinese Academy of Sciences(No.YSBR-061)the Strategic Priority Program on Space Science of Chinese Academy of Sciences(No.E02212A02S)the Youth Innovation Promotion Association of CAS(No.2021450)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220197)the New Cornerstone Science Foundation through the XPLORER PRIZEthe Program for Innovative Talents and Entrepreneur in Jiangsu.In Europesupported by the Swiss National Science Foundation(SNSF),Switzerland,the National Institute for Nuclear Physics(INFN),Italythe European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(No.851103).
文摘The cosmic-ray(CR)electrons and positrons in space are of considerable significance for studying the origin and propagation of CRs.The satellite-borne detector Dark Matter Particle Explorer(DAMPE)has been used to measure the separate electron and positron spectra,as well as the positron fraction.In this study,the Earth's magnetic field is used to distinguish CR electrons and positrons,as the DAMPE detector does not carry an onboard magnet.The energy for the measurements ranges from 10 to 20 GeV,which is currently limited at high energy by the zenith-pointing orientation of DAMPE.The results are consistent with previous measurements based on the magnetic spectrometer by AMS-02 and PAMELA,whereas the results of Fermi-LAT appear to be systematically shifted to larger values.
