The recrystallization and softening resistance of a Cu-6.5Fe-0.3Mg(mass fraction,%)alloy prepared by Process 1(cold rolling heat treatment)and Process 2(hot/cold rolling heat treatment)were studied using Vickers hardn...The recrystallization and softening resistance of a Cu-6.5Fe-0.3Mg(mass fraction,%)alloy prepared by Process 1(cold rolling heat treatment)and Process 2(hot/cold rolling heat treatment)were studied using Vickers hardness tests,tensile tests,scanning electron microscopy and transmission electron microscopy.The softening temperature,hardness and tensile strength of the alloy prepared by Process 2 were 110°C,HV 15 and 114 MPa higher,respectively,than those of the alloy prepared by Process 1 after aging at 300°C.The recrystallization activation energy of the alloys prepared by Process 1 and Process 2 were 72.83 and 98.11 kJ/mol,respectively.The pinning effects of the precipitates of the two alloys on grain boundaries and dislocations were basically the same.The softening mechanism was mainly attributed to the loss of dislocation strengthening.The higher Fe fiber density inhibited the average free migration path of dislocations and grain boundary migration in the alloy,which was the main reason for higher softening temperature of the alloy prepared by Process 2.展开更多
The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside gra...The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite.Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and structures inside this shock-metamorphosed diopside grain,termed phase A,B,C and D in this paper.Phase A is identified as orthorhombic(Ca_(0.663)-Mg_(0.314))SiO_(3)-perovskite which is closely associated with phase B,the vitrified(Mg_(0.642)Ca_(0.290)Fe_(0.098))SiO_(3)perovskite.Phase D is assigned to be(Mg_(0.578)Ca_(0.414))SiO_(3)majorite which is associated with phase C,the vetrified Carich Mg-perovskite with a(Mg_(0.853)Ca_(0.167))SiO_(3)composition.Based on high-pressure and high-temperature experiments,the diopside grain in the melt vein of the Suizhou meteorite would have experienced a P–T regime of 20–24GPa and 1800–>2000℃.Such P–T conditions are high enough for the decomposition of the diopside and the formation of four different silicate phases.The orthorhombic(Ca_(0.663)Mg_(0.314))SiO_(3)perovskite found in the Suizhou L6 chondrite might be considered as the third lower-mantle silicate mineral after bridgmanite and davemaoite after the detailed analyses of its crystal structure and physical properties being completed.展开更多
基金financially supported by the Fundamental Research Funds for the Central Universities,China(No.2020CDJDPT001)the Chongqing Natural Science Foundation,China(No.cstc2021jcyj-msxm X0699)。
基金financial supports from the Department of Science and Technology and other Provincial and Ministerial Level Projects,China(No.204306800086)Science and Technology Projects of Ganzhou Science and Technology Bureau,China(No.204301000194)the Science and Technology Project of Jiangxi Provincial Department of Education,China(No.204201400853)。
文摘The recrystallization and softening resistance of a Cu-6.5Fe-0.3Mg(mass fraction,%)alloy prepared by Process 1(cold rolling heat treatment)and Process 2(hot/cold rolling heat treatment)were studied using Vickers hardness tests,tensile tests,scanning electron microscopy and transmission electron microscopy.The softening temperature,hardness and tensile strength of the alloy prepared by Process 2 were 110°C,HV 15 and 114 MPa higher,respectively,than those of the alloy prepared by Process 1 after aging at 300°C.The recrystallization activation energy of the alloys prepared by Process 1 and Process 2 were 72.83 and 98.11 kJ/mol,respectively.The pinning effects of the precipitates of the two alloys on grain boundaries and dislocations were basically the same.The softening mechanism was mainly attributed to the loss of dislocation strengthening.The higher Fe fiber density inhibited the average free migration path of dislocations and grain boundary migration in the alloy,which was the main reason for higher softening temperature of the alloy prepared by Process 2.
文摘The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite.Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and structures inside this shock-metamorphosed diopside grain,termed phase A,B,C and D in this paper.Phase A is identified as orthorhombic(Ca_(0.663)-Mg_(0.314))SiO_(3)-perovskite which is closely associated with phase B,the vitrified(Mg_(0.642)Ca_(0.290)Fe_(0.098))SiO_(3)perovskite.Phase D is assigned to be(Mg_(0.578)Ca_(0.414))SiO_(3)majorite which is associated with phase C,the vetrified Carich Mg-perovskite with a(Mg_(0.853)Ca_(0.167))SiO_(3)composition.Based on high-pressure and high-temperature experiments,the diopside grain in the melt vein of the Suizhou meteorite would have experienced a P–T regime of 20–24GPa and 1800–>2000℃.Such P–T conditions are high enough for the decomposition of the diopside and the formation of four different silicate phases.The orthorhombic(Ca_(0.663)Mg_(0.314))SiO_(3)perovskite found in the Suizhou L6 chondrite might be considered as the third lower-mantle silicate mineral after bridgmanite and davemaoite after the detailed analyses of its crystal structure and physical properties being completed.
