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
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.
