An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characterist...An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.展开更多
Carbon nanotubes(CNTs)are special types of carbon nanostructures with exceptional physical and mechanical properties such as high elastic modulus,high electrical and thermal conductivities,as well as high surface area...Carbon nanotubes(CNTs)are special types of carbon nanostructures with exceptional physical and mechanical properties such as high elastic modulus,high electrical and thermal conductivities,as well as high surface area and large aspect ratios[1].Given their tubular structure and size,CNTs are conceptualized as one-dimensional nanostructures with a crystalline structure of carbon sp2 hybridization formed by carbon–carbon covalent bonds[1].展开更多
文摘An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.
基金This work was financially supported by the“Centro Mexicano de Innovación en Energía del Océano”(CEMIE-O)The authors gratefully acknowledge the support of“Laboratorio Nacional de Materiales Grafénicos”located in the“Centro de Investigación en Química Aplicada”for TEM characterization.In addition,the authors would like to thank Antonio Banderas for his technical assistance with SEM.
文摘Carbon nanotubes(CNTs)are special types of carbon nanostructures with exceptional physical and mechanical properties such as high elastic modulus,high electrical and thermal conductivities,as well as high surface area and large aspect ratios[1].Given their tubular structure and size,CNTs are conceptualized as one-dimensional nanostructures with a crystalline structure of carbon sp2 hybridization formed by carbon–carbon covalent bonds[1].
