Poly-ether-ether-ketone/nano-silicon nitride(PEEK/nSN)composite scaffolds,fabricated by laser powder bed fusion(LPBF),show great potential for orthopedic applications due to their excellent biological performance and ...Poly-ether-ether-ketone/nano-silicon nitride(PEEK/nSN)composite scaffolds,fabricated by laser powder bed fusion(LPBF),show great potential for orthopedic applications due to their excellent biological performance and mechanical adaptability.However,the effect of nSN on LPBF processability and scaffold properties remains unclear.This study systematically investigates the processability and mechanical per-formance of PEEK/nSN composites to enable reliable clinical fabrication.The results show that adding nSN improves powder flowability and inhibits crystallization,enhancing LPBF processability.The introduction of nSN reduces PEEK’s non-isothermal crystallization Avrami exponent from 3.04 to 2.01,suggesting a transformation from a three-dimensional spherulitic to a two-dimensional lamellar crystal structure.Tensile tests reveal that the presence of nSN alters the optimal process parameters,reducing the optimal laser power from 25 W to 22 W due to increased energy absorption efficiency,as shown by an increase in absorbance at 843 cm^(-1)from 0.27 to 0.35 as the nSN content increases to 2 wt%.Porous diamond-structured scaffolds were fabricated using optimal parameters for pure PEEK,PEEK/1 wt%nSN,and PEEK/2 wt%nSN.Diamond-structured scaffolds fabricated with 1 wt%nSN showed a 12.2%increase in elastic modulus compared to pure PEEK,highlighting the enhanced mechanical performance.Over-all,this study offers key insights into the stable and customizable LPBF fabrication of PEEK/nSN porous scaffolds,providing a foundation for future research on their bioactivity and antibacterial properties for orthopedic applications.展开更多
Ti6Al4V cellular structures were produced by selective laser melting(SLM)and then filled either with beta-tricalcium phosphate(β-TCP)or PEEK(poly-ether-ether-ketone)through powder metallurgy techniques,to improve ost...Ti6Al4V cellular structures were produced by selective laser melting(SLM)and then filled either with beta-tricalcium phosphate(β-TCP)or PEEK(poly-ether-ether-ketone)through powder metallurgy techniques,to improve osteoconductivity and wear resistance.The corrosion behavior of these structures was explored considering its importance for the long-term performance of implants.Results revealed that the incorporation of open cellular pores induced higher electrochemical kinetics when being compared with dense structures.The impregnation ofβ-TCP and PEEK led to the creation of voids or gaps between the metallic matrix and the impregnated material which also influenced the corrosion behavior of the cellular structures.展开更多
The poly-ether-ether-ketone(PEEK)polymer is a semi-crystalline aromatic thermoplastic with outstanding features,such as superior mechanical properties,thermal stability,radiation resistance and excellent chemical and ...The poly-ether-ether-ketone(PEEK)polymer is a semi-crystalline aromatic thermoplastic with outstanding features,such as superior mechanical properties,thermal stability,radiation resistance and excellent chemical and hydrolysis resistance.However,PEEK exhibits a high volume resistivity(1014Ω·m)and surface resistance(1015Ω).This limits its use in the electronics and electromagnetic field.To decrease the resistivity and reduce the thermal expansion of composite materials,this paper modified the PEEK with carbon fiber(CF)and metalized the composites with the electroless Ni-P alloy plating through self-catalyzed deposition,which brings about high conductivity,thermal conductivity,high-temperature weldability resistance and high-low temperature resistance property.The composites and metal coatings were characterized by metallurgical microscope,SEM,and resistance tester.The metal coatings have a uniform surface and low surface resistance less than 10 mΩ~20 mΩ.The thermal shock test at 250°C and the-70°C^100°C high-low temperature environment test were measured.Compared with the electroless plating on unmodified peek,there is no bump and crack,etc.after testing,which shows a good adhesion between the metal coatings and PEEK-CF,high-low temperature resistance as well as high temperature weldability.The researches on the modification of PEEK by carbon fiber and its surface metallization provide technical support for the application of PEEK Composites in radar antenna and other electronic fields.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52235008 and U2341270)the National Natural Science Foundation of China(No.52105341)。
文摘Poly-ether-ether-ketone/nano-silicon nitride(PEEK/nSN)composite scaffolds,fabricated by laser powder bed fusion(LPBF),show great potential for orthopedic applications due to their excellent biological performance and mechanical adaptability.However,the effect of nSN on LPBF processability and scaffold properties remains unclear.This study systematically investigates the processability and mechanical per-formance of PEEK/nSN composites to enable reliable clinical fabrication.The results show that adding nSN improves powder flowability and inhibits crystallization,enhancing LPBF processability.The introduction of nSN reduces PEEK’s non-isothermal crystallization Avrami exponent from 3.04 to 2.01,suggesting a transformation from a three-dimensional spherulitic to a two-dimensional lamellar crystal structure.Tensile tests reveal that the presence of nSN alters the optimal process parameters,reducing the optimal laser power from 25 W to 22 W due to increased energy absorption efficiency,as shown by an increase in absorbance at 843 cm^(-1)from 0.27 to 0.35 as the nSN content increases to 2 wt%.Porous diamond-structured scaffolds were fabricated using optimal parameters for pure PEEK,PEEK/1 wt%nSN,and PEEK/2 wt%nSN.Diamond-structured scaffolds fabricated with 1 wt%nSN showed a 12.2%increase in elastic modulus compared to pure PEEK,highlighting the enhanced mechanical performance.Over-all,this study offers key insights into the stable and customizable LPBF fabrication of PEEK/nSN porous scaffolds,providing a foundation for future research on their bioactivity and antibacterial properties for orthopedic applications.
基金supported by FCT through the grants PD/BD/140202/2018,SFRH/BD/140191/2018 and SFRH/BD/128657/2017the projects PTDC/EMS-TEC/5422/2014 and NORTE-01-0145-FEDER-000018-HAMa BICo+1 种基金supported by FCT with the reference project UID/EEA/04436/2019the financial support through the M-ERA-NET/0001/2015 project(FCT)
文摘Ti6Al4V cellular structures were produced by selective laser melting(SLM)and then filled either with beta-tricalcium phosphate(β-TCP)or PEEK(poly-ether-ether-ketone)through powder metallurgy techniques,to improve osteoconductivity and wear resistance.The corrosion behavior of these structures was explored considering its importance for the long-term performance of implants.Results revealed that the incorporation of open cellular pores induced higher electrochemical kinetics when being compared with dense structures.The impregnation ofβ-TCP and PEEK led to the creation of voids or gaps between the metallic matrix and the impregnated material which also influenced the corrosion behavior of the cellular structures.
文摘The poly-ether-ether-ketone(PEEK)polymer is a semi-crystalline aromatic thermoplastic with outstanding features,such as superior mechanical properties,thermal stability,radiation resistance and excellent chemical and hydrolysis resistance.However,PEEK exhibits a high volume resistivity(1014Ω·m)and surface resistance(1015Ω).This limits its use in the electronics and electromagnetic field.To decrease the resistivity and reduce the thermal expansion of composite materials,this paper modified the PEEK with carbon fiber(CF)and metalized the composites with the electroless Ni-P alloy plating through self-catalyzed deposition,which brings about high conductivity,thermal conductivity,high-temperature weldability resistance and high-low temperature resistance property.The composites and metal coatings were characterized by metallurgical microscope,SEM,and resistance tester.The metal coatings have a uniform surface and low surface resistance less than 10 mΩ~20 mΩ.The thermal shock test at 250°C and the-70°C^100°C high-low temperature environment test were measured.Compared with the electroless plating on unmodified peek,there is no bump and crack,etc.after testing,which shows a good adhesion between the metal coatings and PEEK-CF,high-low temperature resistance as well as high temperature weldability.The researches on the modification of PEEK by carbon fiber and its surface metallization provide technical support for the application of PEEK Composites in radar antenna and other electronic fields.
