Cu-1%Cr(mass fraction)and Cu-1%Cr-5%carbon nanotube(CNT)(mass fraction)nanocomposite powders were produced by mechanical alloying and consolidated by hot pressing.Then,nanocomposites were hot-rolled by the order of 50...Cu-1%Cr(mass fraction)and Cu-1%Cr-5%carbon nanotube(CNT)(mass fraction)nanocomposite powders were produced by mechanical alloying and consolidated by hot pressing.Then,nanocomposites were hot-rolled by the order of 50%reduction at 650°C.The structure and microstructure were investigated by X-ray diffractometry(XRD)and scanning electron microscopy(SEM).Relative density,microhardness,thermal stability,electrical and wear properties were evaluated.Compared to the Cu-Cr sample,the relative density of Cu-Cr-CNT sample is greatly improved from 75%to near full density of 98%by hot rolling.Although electrical conductivity and microhardness increase in both Cu-Cr and Cu-Cr-CNT nanocomposites after hot rolling,the effect of hot rolling on the enhancement is more prominent in the presence of CNTs.The microhardness and electrical conductivity of hot-rolled Cu-Cr-CNT nanocomposite approach HV 175 and 68%(IACS),respectively.Also,hot rolling is more effective on thermal stability improvement of Cu-Cr-CNT nanocomposite compared to Cu-Cr composite.However,after hot rolling,both the friction coef?cient and wear loss of the Cu-Cr sample display higher reduction than those of Cu-Cr-CNT nanocomposite owing to different wear mechanisms.After hot rolling,friction coefficient and wear loss of Cu-Cr sample display variation of 25%and 62%,respectively.展开更多
基金the financial support of University of Tehran for this researchfinancial supports of Iran Nanotechnology Initiative Council
文摘Cu-1%Cr(mass fraction)and Cu-1%Cr-5%carbon nanotube(CNT)(mass fraction)nanocomposite powders were produced by mechanical alloying and consolidated by hot pressing.Then,nanocomposites were hot-rolled by the order of 50%reduction at 650°C.The structure and microstructure were investigated by X-ray diffractometry(XRD)and scanning electron microscopy(SEM).Relative density,microhardness,thermal stability,electrical and wear properties were evaluated.Compared to the Cu-Cr sample,the relative density of Cu-Cr-CNT sample is greatly improved from 75%to near full density of 98%by hot rolling.Although electrical conductivity and microhardness increase in both Cu-Cr and Cu-Cr-CNT nanocomposites after hot rolling,the effect of hot rolling on the enhancement is more prominent in the presence of CNTs.The microhardness and electrical conductivity of hot-rolled Cu-Cr-CNT nanocomposite approach HV 175 and 68%(IACS),respectively.Also,hot rolling is more effective on thermal stability improvement of Cu-Cr-CNT nanocomposite compared to Cu-Cr composite.However,after hot rolling,both the friction coef?cient and wear loss of the Cu-Cr sample display higher reduction than those of Cu-Cr-CNT nanocomposite owing to different wear mechanisms.After hot rolling,friction coefficient and wear loss of Cu-Cr sample display variation of 25%and 62%,respectively.
