A comprehensive survey was made of various candidate high temperature materials for gas turbine use, and their relative merits and drawbacks were assessed. It is shown that superalloys, fine-tuned, will be persistent ...A comprehensive survey was made of various candidate high temperature materials for gas turbine use, and their relative merits and drawbacks were assessed. It is shown that superalloys, fine-tuned, will be persistent for the next few decades, to be followed up by high temperature intermetallics. For advanced ceramics, the problems of reliability and cost will have to be solved before they can be used in critical parts of engines.So are C/C composites with their oxidation problem. Surface modification and development of thermal barrier coatings can effectively overcome many problems of gas turbine materials and these technologies should be emphasized.展开更多
A calcium sulfate whisker （CSW） coated with glutaraldehyde crosslinked chitosan （GACS） was prepared to reinforce polyvinyl chloride （PVC） in this study. The results show that the optimum concentration of both ch...A calcium sulfate whisker （CSW） coated with glutaraldehyde crosslinked chitosan （GACS） was prepared to reinforce polyvinyl chloride （PVC） in this study. The results show that the optimum concentration of both chitosan （CS） and glutaraldehyde （GA） is 0.05 wt%. The tensile strength, impact strength, flexural modulus and vicat softening temperature of the PVC composite with 12 wt% of modified CSW are in- creased by 1 Z5%, 40.4%, 0.8% and 3.8% compared with those of the PVC composite with 12 wt~ of unmodified CSW, and by 2.9%, 42.4%, 2Z1% and 6.8% compared with those of pure PVC, respectively. The dynamic mechanical analysis results indicate that the modified CSW/PVC composite exhibits much higher storage modulus and glass transition temperature than those of unmodified CSW/PVC composite and pure PVC. In addition, the modified CSW/PVC composite also demonstrates good thermal properties with a high rapidest decomposition temperature （Trvd） and char residue. The scanning electron microscopy images of tensile-fractured surfaces show that the modified CSW has a strong interfacial adhesion with PVC matrix.展开更多
文摘A comprehensive survey was made of various candidate high temperature materials for gas turbine use, and their relative merits and drawbacks were assessed. It is shown that superalloys, fine-tuned, will be persistent for the next few decades, to be followed up by high temperature intermetallics. For advanced ceramics, the problems of reliability and cost will have to be solved before they can be used in critical parts of engines.So are C/C composites with their oxidation problem. Surface modification and development of thermal barrier coatings can effectively overcome many problems of gas turbine materials and these technologies should be emphasized.
基金supported by the National Natural Science Foundation of China (No. U 1507123)the Foundation from Qinghai Science and Technology Department (No. 2014-HZ-817)
文摘A calcium sulfate whisker （CSW） coated with glutaraldehyde crosslinked chitosan （GACS） was prepared to reinforce polyvinyl chloride （PVC） in this study. The results show that the optimum concentration of both chitosan （CS） and glutaraldehyde （GA） is 0.05 wt%. The tensile strength, impact strength, flexural modulus and vicat softening temperature of the PVC composite with 12 wt% of modified CSW are in- creased by 1 Z5%, 40.4%, 0.8% and 3.8% compared with those of the PVC composite with 12 wt~ of unmodified CSW, and by 2.9%, 42.4%, 2Z1% and 6.8% compared with those of pure PVC, respectively. The dynamic mechanical analysis results indicate that the modified CSW/PVC composite exhibits much higher storage modulus and glass transition temperature than those of unmodified CSW/PVC composite and pure PVC. In addition, the modified CSW/PVC composite also demonstrates good thermal properties with a high rapidest decomposition temperature （Trvd） and char residue. The scanning electron microscopy images of tensile-fractured surfaces show that the modified CSW has a strong interfacial adhesion with PVC matrix.
