摘要
High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al composites.Two powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to investigate the dispersion and damage of CNTs during HEBM process.HEBM-1 evolution process involved powder fl attening,cold-welding and fracture,while HEBM-2 evolution process consisted of powder fl attening and fracture.For HEBM-1,the repetitive fracture and cold-welding process was effective for dispersing CNTs.However,the powder fl attening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be unravelled.Because of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of CNTs.It indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.
基金
supported by the Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-JSC015)
the National Key R&D Program of China(No.2017YFB0703104)
the Project of manned spaceflight(No.040103)
the National Natural Science Foundation of China(Nos.51931009,51871215)
the Youth Innovation Promotion Association CAS(No.2020197)。
