The research team led by Chu Yanhui from the School of Materials Science and Engineering at South China University of Technology has successfully prepared a high entropy porous boride ceramic material with both super mechanical strength and high thermal insulation properties through multi-scale structural design.Meanwhile,the material also exhibits high temperature stability at 2000℃.The relevant research results were recently published in the international journal Advanced Materials.
  With the continuous improvement of flight speed,the new generation of hypersonic aircraft has put forward stricter requirements for the mechanical strength,thermal conductivity,and temperature resistance of insulation materials.Porous ceramic materials with excellent mechanical strength and thermal insulation properties have always been the pursuit of scientists,however,these two properties are to some extent mutually restrictive.
  "If the relative density of porous ceramics is simply reduced,the thermal insulation performance of the material can be significantly improved,but this often leads to a significant decrease in the material's mechanical strength.At the same time,traditional porous ceramic materials generally have temperature resistance below 1500℃,and they often face problems such as volume shrinkage and mechanical performance degradation during high-temperature service."Chu Yanhui introduced.
  The superiority of the high entropy porous boride ceramic material prepared by the research team lies in the"three magic weapons":ultra-fine pores constructed at the microscopic scale,strong intergranular interface bonding at the nanoscale,and severe lattice distortion at the atomic scale.
  It is reported that at the micrometer scale,the team completed sintering within tens of seconds using ultra-high temperature rapid synthesis technology to suppress grain growth and construct uniformly distributed submicron level ultrafine pores within the material.At the nanoscale,the team established strong interfacial bonding between grains through further solid solution reactions.At the atomic scale,the team improved the intrinsic mechanical strength of borides by introducing severe lattice distortion of 9-membered cations,enhancing the stress and mass field fluctuations within the lattice.
  In mechanical performance testing,the high entropy porous ceramic material exhibits excellent high-temperature compressive strength,excellent high-temperature insulation performance,and thermal stability,which will have broad application prospects in the fields of aerospace,energy and chemical engineering.