High temperature creep resistance and the correlation between the microstructure and mechanical properties of Mg-9Al-1Si-xY were studied. The study shows that the main strengthening phase Mg2Si presents as coarse Chin...High temperature creep resistance and the correlation between the microstructure and mechanical properties of Mg-9Al-1Si-xY were studied. The study shows that the main strengthening phase Mg2Si presents as coarse Chinese script distributed around the grain boundary after the addition of 1% Si to MggAl alloys. Under stress, the microcrack prefers to occur in the interface between the Mg2Si phase and the matrix. The addition of a small amount of Y into Mg-9Al-1Si alloys results phology of the in refinement of microstructure. MorMg2Si phases change from coarse Chinese script shape to fine polygonal shape. Owing to the improvement of microstructure, the mechanical properties of Mg-9Al-1Si alloys at both ambient and elevated temperatures are increased. The high temperature creep resistant properties of Mg-9Al-1Si-xY rises with the increase of Y content.展开更多
High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarif...High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.展开更多
Measured results of magnetoelectric (ME) and converse magnetoelectric (CME) effects of TbxDy1-xFe2-y/ Pb(Mg1/3Nb2/3)(1-x)TixO3/TbxDy1-xFe2-y (TD/PMNT/TD) and PMNT/TD/PMNT laminated composites are pre- sented. ME effec...Measured results of magnetoelectric (ME) and converse magnetoelectric (CME) effects of TbxDy1-xFe2-y/ Pb(Mg1/3Nb2/3)(1-x)TixO3/TbxDy1-xFe2-y (TD/PMNT/TD) and PMNT/TD/PMNT laminated composites are pre- sented. ME effect was determined by measuring laminate voltage output under a Helmholtz-gener- ated AC field biased by a DC field (0―1 kOe) (1 Oe = 79.58 A/m). The CME effect was measured by re- cording the voltage induced in a solenoid encompassing the ME sample while exposed to a DC bias field and PMNT layer driven by a 10 V AC source. The ME and CME responses in the two laminated structure are linear. The highest values of ME coefficients in TD/PMNT/TD and PMNT/TD/PMNT com- posites are 384 mV/Oe and 158 mV/Oe, respectively, while the highest values of CME coefficients in the two composites are 118 mG/V and 162 mG/V (1 G=10-4 T), respectively.展开更多
文摘High temperature creep resistance and the correlation between the microstructure and mechanical properties of Mg-9Al-1Si-xY were studied. The study shows that the main strengthening phase Mg2Si presents as coarse Chinese script distributed around the grain boundary after the addition of 1% Si to MggAl alloys. Under stress, the microcrack prefers to occur in the interface between the Mg2Si phase and the matrix. The addition of a small amount of Y into Mg-9Al-1Si alloys results phology of the in refinement of microstructure. MorMg2Si phases change from coarse Chinese script shape to fine polygonal shape. Owing to the improvement of microstructure, the mechanical properties of Mg-9Al-1Si alloys at both ambient and elevated temperatures are increased. The high temperature creep resistant properties of Mg-9Al-1Si-xY rises with the increase of Y content.
基金financially supported by the National Natural Science Foundation of China(Nos.62074018,62174015 and 62275032)the Developing Project of Science and Technology of Jilin Province(No.20210509061RQ)+3 种基金the Natural Science Foundation of Jilin Province(No.20210101473JC)National Key R&D Program of China(No.2021YFB3201901)The Natural Science Foundation of Chongqing China(No.cstc2021jcyjmsxmX1060)supported by R&D project of Collighter Co.,Ltd。
文摘High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.
基金Supported by the Hi-Tech Research and Development Program of China (Grant No. 2006AA03Z107)National Natural Science Foundation of China (Grant Nos. 50432030, 50777065, 50602047)+3 种基金Scientific Innovation Program of the Chinese Academy of Sciences (Grant No. KGCX2-YW-111-7)Shanghai Municipal Gov-ernment (Grant No. 06DZ05016)Innovation Funds from Shanghai Institute of Ceramics of Chinese Academy of Sciences (Grant No. SCX0608)Research Grants Council of the HKSAR Government (PolyU 5255/03E and PolyU 5122/05E)
文摘Measured results of magnetoelectric (ME) and converse magnetoelectric (CME) effects of TbxDy1-xFe2-y/ Pb(Mg1/3Nb2/3)(1-x)TixO3/TbxDy1-xFe2-y (TD/PMNT/TD) and PMNT/TD/PMNT laminated composites are pre- sented. ME effect was determined by measuring laminate voltage output under a Helmholtz-gener- ated AC field biased by a DC field (0―1 kOe) (1 Oe = 79.58 A/m). The CME effect was measured by re- cording the voltage induced in a solenoid encompassing the ME sample while exposed to a DC bias field and PMNT layer driven by a 10 V AC source. The ME and CME responses in the two laminated structure are linear. The highest values of ME coefficients in TD/PMNT/TD and PMNT/TD/PMNT com- posites are 384 mV/Oe and 158 mV/Oe, respectively, while the highest values of CME coefficients in the two composites are 118 mG/V and 162 mG/V (1 G=10-4 T), respectively.
