Amorphization of Cu-Zr and Ni-Zr systems by mechanical alloying(MA)was studied by X-ray diffraction.The results show that the amorphization is not merely a simple interdiffusion by thermal activation;in addition,the s...Amorphization of Cu-Zr and Ni-Zr systems by mechanical alloying(MA)was studied by X-ray diffraction.The results show that the amorphization is not merely a simple interdiffusion by thermal activation;in addition,the strain induced by MA also accelerates this process.展开更多
The crystallization behaviour of a-Pd_(80)Si_(20) in the high temperature internal friction peak region is systematically studied by DSC and X-ray diffraction techniques.
The in situ observation of crystallization behavior of metallic glass Co_(65.1) Fe_(4.7)Ni_(4.6)Si_(10.2) B_(15.4)during heat-ing in an electron microscope is carried out. The three crystalline phases correlated with...The in situ observation of crystallization behavior of metallic glass Co_(65.1) Fe_(4.7)Ni_(4.6)Si_(10.2) B_(15.4)during heat-ing in an electron microscope is carried out. The three crystalline phases correlated with the exothermalpeaks on the DSC profiles are identified by means of electron diffraction. and they are all stable phasesfrom room temperature to 1000 K.Besides.an anomalous crystalline phase with long spikes along the direction in the reciprocal lattice space is found during crystallization. and its structural model is also discussed.展开更多
Variation of some thermodynamic functions of an amorphous alloy Pd_(77.5)Ni_(6.0)Si_(16.5) in glass transition temperature region during various scans was measured by a differential scanning calorimeter.The Gibbs free...Variation of some thermodynamic functions of an amorphous alloy Pd_(77.5)Ni_(6.0)Si_(16.5) in glass transition temperature region during various scans was measured by a differential scanning calorimeter.The Gibbs free energy of glassy state was examined to be larger than that of the undercooled liquid state when the specimen was heated up to the glass transition temperature region,which supports the idea of what there are thermodynamic origins underlying glass transition process.On the other hand,it was found that glass transition behaved differently during heating and cooling scans.Moreover,with increase of heating rate,the glass transition process was delayed gradually to higher temperatures.It can be concluded that glass transition is a kinetically modified thermodynamic phase transformation.展开更多
During structural relaxation of a glassy matrix,the apparent internal friction(Q^(-1))decreased with the increase of annealing time(t).The dependence of Q^(-1) on t can be shown as Q^(-1)=At^(-β)+B,where A,B andβare...During structural relaxation of a glassy matrix,the apparent internal friction(Q^(-1))decreased with the increase of annealing time(t).The dependence of Q^(-1) on t can be shown as Q^(-1)=At^(-β)+B,where A,B andβare constants.展开更多
The effect of neutron-irradiation on crystallization of Cu-Ti glasses of four compositions was systematically studied by differential scanning calorimetry(DSC)and internal friction measurements.The results show that t...The effect of neutron-irradiation on crystallization of Cu-Ti glasses of four compositions was systematically studied by differential scanning calorimetry(DSC)and internal friction measurements.The results show that the susceptibility of the glasses to irradiation is quite composition dependent.展开更多
基金Project supported by National Science Foundation of China。
文摘Amorphization of Cu-Zr and Ni-Zr systems by mechanical alloying(MA)was studied by X-ray diffraction.The results show that the amorphization is not merely a simple interdiffusion by thermal activation;in addition,the strain induced by MA also accelerates this process.
文摘The crystallization behaviour of a-Pd_(80)Si_(20) in the high temperature internal friction peak region is systematically studied by DSC and X-ray diffraction techniques.
文摘The in situ observation of crystallization behavior of metallic glass Co_(65.1) Fe_(4.7)Ni_(4.6)Si_(10.2) B_(15.4)during heat-ing in an electron microscope is carried out. The three crystalline phases correlated with the exothermalpeaks on the DSC profiles are identified by means of electron diffraction. and they are all stable phasesfrom room temperature to 1000 K.Besides.an anomalous crystalline phase with long spikes along the direction in the reciprocal lattice space is found during crystallization. and its structural model is also discussed.
文摘Variation of some thermodynamic functions of an amorphous alloy Pd_(77.5)Ni_(6.0)Si_(16.5) in glass transition temperature region during various scans was measured by a differential scanning calorimeter.The Gibbs free energy of glassy state was examined to be larger than that of the undercooled liquid state when the specimen was heated up to the glass transition temperature region,which supports the idea of what there are thermodynamic origins underlying glass transition process.On the other hand,it was found that glass transition behaved differently during heating and cooling scans.Moreover,with increase of heating rate,the glass transition process was delayed gradually to higher temperatures.It can be concluded that glass transition is a kinetically modified thermodynamic phase transformation.
文摘During structural relaxation of a glassy matrix,the apparent internal friction(Q^(-1))decreased with the increase of annealing time(t).The dependence of Q^(-1) on t can be shown as Q^(-1)=At^(-β)+B,where A,B andβare constants.
基金supported by the National Science Fund of China。
文摘The effect of neutron-irradiation on crystallization of Cu-Ti glasses of four compositions was systematically studied by differential scanning calorimetry(DSC)and internal friction measurements.The results show that the susceptibility of the glasses to irradiation is quite composition dependent.
