A newly developed Mg-4Zn-2La-3Y alloy with high strength was fabricated by high-pressure die casting method,and its microstructures were thoroughly studied using transmission electron microscopy.The results demonstrat...A newly developed Mg-4Zn-2La-3Y alloy with high strength was fabricated by high-pressure die casting method,and its microstructures were thoroughly studied using transmission electron microscopy.The results demonstrate that it owns fine grains and approximately highly interconnected intermetallic phase skeletons,and exhibits ultra-high strength at both room and high temperatures.Interestingly,the eutectic intermetallic skeleton of this alloys is consisted of numerous fine particles,which are mainly consisted of two intermetallic phases,namely W and Mg12RE.Multiple{101}twins and SFs were found in the Mg12RE phase while a few of SFs in the W phase.Additionally,minor long-period stacking ordered phase was observed in the eutectoid phase,and it probably nucleated on the Mg12RE phase following a certain OR as(0002)14H//(110)Mg12REand[1120]14H//[111]Mg12RE,or(0002)14H//(211)Mg12REand[1120]14H//[111]Mg12RE.This special intermetallic skeleton with many interfaces and planar faults can efficiently transfer dislocations across grain boundaries,and this is the key factor for the outstanding mechanical properties of the studied alloy.展开更多
The hairpin probe using microwave resonance in plasma is applicable to high pressure 1.33 ×10^3-1.01×10^5 Pa）） as developed recently. In this work, an analytic model of the hairpin resonator probe surround...The hairpin probe using microwave resonance in plasma is applicable to high pressure 1.33 ×10^3-1.01×10^5 Pa）） as developed recently. In this work, an analytic model of the hairpin resonator probe surrounded by a thin dielectric layer and a sheath layer is proposed. The correction factor due to these surroundings is analytically found and confirmed by electromagnetic field finite difference time domain simulation, thus enabling the accurate measurement of electron density in a high-pressure non-equilibrium uniform discharge.展开更多
The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesi...The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesiowtistite, and ringwoodite, with FeNi-FeS inter- growths. The observation and character of ring-like selected electron diffraction （SAED） patterns indicate that Lhe idiomorphic garnet crystals in the vein matrix have different orientations. The polycrystalline nature of magnesiowtistite is also confirmed by a ring-like SAED pattern. Both garnet and magnesiowtistite crystals showed sharp Jiffraction spots, signifying the good crystallinity of these ：wo minerals. The SAED pattern of cryptocrystalline 5ngwoodite shows only diffuse concentric diffraction tings. FeNi metal and troilite （FeS）, which were molten during the shock event, occur in the matrix as fine eutectic FeNi-FeS intergrowths filling the interstices between garaet and magnesiowiistite grains. Based on the phase dia- gram of the Allende chondrite and the results of this TEM study, it is inferred that majorite-pyrope garnet first crystallized from the Suizhou chondritic melt at 22-26 GPa, Followed by crystallization of magnesiowtistite at 20-24 GPa, and then ringwoodite at 18-20 GPa. The eutectic intergrowths of FeNi-metal and troilite are proposed to have crystallized during meteorite cooling and solidified at the last stage of vein formation.展开更多
基金supported by the National Natural Science Foundation of China under grants no.51701200 and 51871069the Scientific and Technological Developing Scheme of Jilin Province under grants no.20200801048GH。
文摘A newly developed Mg-4Zn-2La-3Y alloy with high strength was fabricated by high-pressure die casting method,and its microstructures were thoroughly studied using transmission electron microscopy.The results demonstrate that it owns fine grains and approximately highly interconnected intermetallic phase skeletons,and exhibits ultra-high strength at both room and high temperatures.Interestingly,the eutectic intermetallic skeleton of this alloys is consisted of numerous fine particles,which are mainly consisted of two intermetallic phases,namely W and Mg12RE.Multiple{101}twins and SFs were found in the Mg12RE phase while a few of SFs in the W phase.Additionally,minor long-period stacking ordered phase was observed in the eutectoid phase,and it probably nucleated on the Mg12RE phase following a certain OR as(0002)14H//(110)Mg12REand[1120]14H//[111]Mg12RE,or(0002)14H//(211)Mg12REand[1120]14H//[111]Mg12RE.This special intermetallic skeleton with many interfaces and planar faults can efficiently transfer dislocations across grain boundaries,and this is the key factor for the outstanding mechanical properties of the studied alloy.
基金supported by the National Natural Science Foundation of China (Grant No. 10835004 )the 2nd Knowledge Cluster Research Project of Japan:Tokai Region Nanotechnology Manufacturing Cluster (Innovation of Environment Friendly Highly Functional Materials and Devices)
文摘The hairpin probe using microwave resonance in plasma is applicable to high pressure 1.33 ×10^3-1.01×10^5 Pa）） as developed recently. In this work, an analytic model of the hairpin resonator probe surrounded by a thin dielectric layer and a sheath layer is proposed. The correction factor due to these surroundings is analytically found and confirmed by electromagnetic field finite difference time domain simulation, thus enabling the accurate measurement of electron density in a high-pressure non-equilibrium uniform discharge.
基金financially supported by National Natural Science foundation of China under Grant 41172046 and 40972044 in part
文摘The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesiowtistite, and ringwoodite, with FeNi-FeS inter- growths. The observation and character of ring-like selected electron diffraction （SAED） patterns indicate that Lhe idiomorphic garnet crystals in the vein matrix have different orientations. The polycrystalline nature of magnesiowtistite is also confirmed by a ring-like SAED pattern. Both garnet and magnesiowtistite crystals showed sharp Jiffraction spots, signifying the good crystallinity of these ：wo minerals. The SAED pattern of cryptocrystalline 5ngwoodite shows only diffuse concentric diffraction tings. FeNi metal and troilite （FeS）, which were molten during the shock event, occur in the matrix as fine eutectic FeNi-FeS intergrowths filling the interstices between garaet and magnesiowiistite grains. Based on the phase dia- gram of the Allende chondrite and the results of this TEM study, it is inferred that majorite-pyrope garnet first crystallized from the Suizhou chondritic melt at 22-26 GPa, Followed by crystallization of magnesiowtistite at 20-24 GPa, and then ringwoodite at 18-20 GPa. The eutectic intergrowths of FeNi-metal and troilite are proposed to have crystallized during meteorite cooling and solidified at the last stage of vein formation.
