Papers by Author: Lan Zhu Zhang

Abstract: The tensile properties of polyetheretherketone (PEEK) composites, which were reinforced with short fibers, such as short carbon fiber (SCF), short glass fiber (SGF), or filled with polytetrafluoroethylene (PTEF), expanded graphite and nano material TiO2 were examined and studied. The weight content of short fibers, PTFE and expanded graphite was varied from 0-15%, and of TiO2 was varied from 0-8%. The results showed, with increasing of the weight content of short fibers, the tensile performance (tensile strength and modulus) of PEEK composites was increased rapidly. If the weight percent of short fibers was more than 10%, this increasing tendency became slowly. With the increasing of PTFE content, the tensile strength was increased at first and then decreased rapidly. However, the tensile modulus kept constant during the change of PTFE content. The influence of expanded graphite and nano particles TiO2 on mechanical properties of PEEK composites was also be studied here. Meanwhile, the reasons of different influence of these fillers were analyzed during microstructure changes of PEEK composites with SEM photographs.

Abstract: Because of the excellent performance of Polyetheretherketone (PEEK), it is widely used in aerospace, mechanic, electronic and auto industry. Here the properties of injected molded PEEK composites reinforced by short carbon fiber (SCF), and the influence of SCF on the mechanical performance and thermal expansion performance were studied. It was indicated how the mechanical and thermal performance were changed with SCF content. Also the microstructure of PEEK composites was studied by taking SEM photographs. The results showed, in the here studied range of SCF content, the mechanical performance of PEEK composites rapidly increased with the increasing of SCF content. While the weight percent of short fibers was more than 10%, this increasing tendency became slow. SEM photographs showed, the interaction between base material PEEK and SCF was good, that because SCF could be good connected with PEEK base material, and the filling with SCF could also decrease the thermal expansion coefficient of PEEK composites.

Abstract: To ensure cryogenic vessels working safely and efficiently is a common focus for governments, manufacturers and customers. Chinese national standard system of gas and material compatibility in cryogenic vessels has still not be build. It is necessary to make a research on international standard about it. In this paper, the main international standard of gas and material compatibility in cryogenic vessels and the international standards of ignition test methods were described.