Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature,-10,-20 and-30℃,respectively.Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry...Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature,-10,-20 and-30℃,respectively.Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry(XRD),X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM).The results show that lowering temperature can delay mechanical alloying(MA)process of Cu-Zn system with negative mixing enthalpy,and promote MA process of Cu-Cr system with positive mixing enthalpy.As for Cu-Cr and Cu-Zn powders milled at-10℃,lamellar structures are firstly formed,while fewer lamellar particles can be found when the powder is milled at-20℃.When the alloyed powder is annealed at 1 000℃,Cu(Cr)solid solution is decomposed and Cr precipitates from Cu matrix,whereas Cu(Zn)solid solution keeps stable.展开更多
基金Project(20050698017)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaKey Project(105159)supported by Chinese Ministry of EducationProject(NCET-05-0839)supported by Program for New Century Excellent Talents in University
文摘Cu-Zn and Cu-Cr powders were milled with an attritor mill at room temperature,-10,-20 and-30℃,respectively.Phase transformation and morphology evolution of the alloyed powder were investigated by X-ray diffractometry(XRD),X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM).The results show that lowering temperature can delay mechanical alloying(MA)process of Cu-Zn system with negative mixing enthalpy,and promote MA process of Cu-Cr system with positive mixing enthalpy.As for Cu-Cr and Cu-Zn powders milled at-10℃,lamellar structures are firstly formed,while fewer lamellar particles can be found when the powder is milled at-20℃.When the alloyed powder is annealed at 1 000℃,Cu(Cr)solid solution is decomposed and Cr precipitates from Cu matrix,whereas Cu(Zn)solid solution keeps stable.
