The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. ...The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. The characterized fatigue delamination of the plasma sprayed coatings was evidently different from that of the homogeneous materials. The lamellar cohesion, oxide inclusions and porosity were critical factors that controlled the fretting wear resistance. In the view of contact mechanics, the fretting wear behavior of plasma spraying coatings was characterized.展开更多
A two-stage strain rate deformation method is proposed to enhance the superplasticity in a hot extruded AZ61 alloy. In the stage-one of deformation, a relatively high strain rate was applied in order to obtain fine gr...A two-stage strain rate deformation method is proposed to enhance the superplasticity in a hot extruded AZ61 alloy. In the stage-one of deformation, a relatively high strain rate was applied in order to obtain fine grains through dynamic recrystallization. The optimum strain rate for DRX at 300℃ was identified as -5×10-3s-1. Stage-two is conducted at relatively low strain rate in order to utilize the fine grains refined by DRX during stage-one to make the grain boundary sliding operate more smoothly, which resulting in enhanced superplastic elongation from 350% to 440%.展开更多
The aging processes in Cu 3.2Ni 0.75Si alloy were examined by means of transmission electron microscope , X ray diffractometer and high resolution transmission electron microscopy. It is concluded that before the form...The aging processes in Cu 3.2Ni 0.75Si alloy were examined by means of transmission electron microscope , X ray diffractometer and high resolution transmission electron microscopy. It is concluded that before the formation of Ni 2Si phase there exist continuous phase transformation processes, namely ordering, spinodal decomposition. Thereafter, the solute rich zones form Ni 2Si phase which is coherent with the matrix.展开更多
The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (trans...The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (transmission electronic microscope) and SEM (scanning electron microscope). It was found that MA-POE, as an impact modifier, had a profound effect upon the toughness of the PA-6/nano-CaCO3 composite. In particular, by adopting two-stage blending route, the microstructure of the ternary composites turned to core-shell structure, and the impact toughness was improved greatly. At the same time, tensile strength and dynamic storage modulus (E1) were higher than those with one-stage blending route processed ternary composite. The results suggest that blending routes may improve the properties of PA-6/nano-CaCO3/MA-POE ternary composites.展开更多
The phase equilibrium relations of the ternary Ni-Cr-Zr system at 900℃ have been investigated by means of diffusion triple and electron probe microanalysis (EMPA) techniques. A series of tie lines and triangles have ...The phase equilibrium relations of the ternary Ni-Cr-Zr system at 900℃ have been investigated by means of diffusion triple and electron probe microanalysis (EMPA) techniques. A series of tie lines and triangles have been determined, and the corresponding tentative isothermal section is presented based on the current information.展开更多
Heat treatment on the laser powder synthesized Ni20A130Fe intermetallic alloy was conducted. The microstructure and composition were analyzed by scanning electron microscopy. The results showed that heat treatment cou...Heat treatment on the laser powder synthesized Ni20A130Fe intermetallic alloy was conducted. The microstructure and composition were analyzed by scanning electron microscopy. The results showed that heat treatment could promote the precipitation of the ductile phase and the coalescence and growth of the sub-crystal grains. These were desirable to improve the ambient ductility and the elevated-temperature strength of the Ni20A130Feintermetallic alloy.展开更多
Owing to both of its high carrier concentration and large band gap, ZnO:Al (ZAO) films which is an n-type degenerate semiconductor, exhibits low resistance and high transmittance in the visible range. This work studie...Owing to both of its high carrier concentration and large band gap, ZnO:Al (ZAO) films which is an n-type degenerate semiconductor, exhibits low resistance and high transmittance in the visible range. This work studies the crystal structure, optical and electrical properties and preparation methods of ZAO films, and discusses the existing problems and application prospective of ZAO films.展开更多
The Kokchetav Massif of northern Kazakhstan is a typelocality of occurrence of microdiamonds in ultrahighpressure metamorphic" rocks. It records continental subduction and exhumation from depths greater than 120 ...The Kokchetav Massif of northern Kazakhstan is a typelocality of occurrence of microdiamonds in ultrahighpressure metamorphic" rocks. It records continental subduction and exhumation from depths greater than 120 km and provides unparalleled insights into mantle dynamics, global material recycling and the processes responsible for the genesis and destruction of continent. Through the support of a US Civilian Development and Research Fund, a group of Russian, US, Taiwan Residents and Kazakhstan geologists visited the reconstructed 800-m underground gallery to conduct field survey and sample collections. This gallery provides a useful geologic laboratory for international community to undertake similar geotectonic or different ecological and environmental studies.展开更多
Surface modification of calcium bicarbonate powder with isopropyl triisostearoyl titanate (TTS) by microwave-assisted heating was studied in the present work. The features of microwave treated powder show obvious supe...Surface modification of calcium bicarbonate powder with isopropyl triisostearoyl titanate (TTS) by microwave-assisted heating was studied in the present work. The features of microwave treated powder show obvious superiority to those of powder samples treated by traditional surface modification method and of untreated calcium bicarbonate — in suspension turbidity, suction potential, contact angle with water, and mechanical properties of their composites with PVC resin.展开更多
文摘The fretting wear behavior of plasma spraying CoCrW and Cr3C2-NiCr coatings were investigated. The results showed both plasma spraying coatings were inferior to K417 nickel superalloy in the fretting wear resistance. The characterized fatigue delamination of the plasma sprayed coatings was evidently different from that of the homogeneous materials. The lamellar cohesion, oxide inclusions and porosity were critical factors that controlled the fretting wear resistance. In the view of contact mechanics, the fretting wear behavior of plasma spraying coatings was characterized.
文摘A two-stage strain rate deformation method is proposed to enhance the superplasticity in a hot extruded AZ61 alloy. In the stage-one of deformation, a relatively high strain rate was applied in order to obtain fine grains through dynamic recrystallization. The optimum strain rate for DRX at 300℃ was identified as -5×10-3s-1. Stage-two is conducted at relatively low strain rate in order to utilize the fine grains refined by DRX during stage-one to make the grain boundary sliding operate more smoothly, which resulting in enhanced superplastic elongation from 350% to 440%.
文摘The aging processes in Cu 3.2Ni 0.75Si alloy were examined by means of transmission electron microscope , X ray diffractometer and high resolution transmission electron microscopy. It is concluded that before the formation of Ni 2Si phase there exist continuous phase transformation processes, namely ordering, spinodal decomposition. Thereafter, the solute rich zones form Ni 2Si phase which is coherent with the matrix.
基金This work was financially supported by the National Natural Science Foundation of China under grant No.29934070.
文摘The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (transmission electronic microscope) and SEM (scanning electron microscope). It was found that MA-POE, as an impact modifier, had a profound effect upon the toughness of the PA-6/nano-CaCO3 composite. In particular, by adopting two-stage blending route, the microstructure of the ternary composites turned to core-shell structure, and the impact toughness was improved greatly. At the same time, tensile strength and dynamic storage modulus (E1) were higher than those with one-stage blending route processed ternary composite. The results suggest that blending routes may improve the properties of PA-6/nano-CaCO3/MA-POE ternary composites.
基金This work is financed by the NSFC (Contract number: 59871065) here the authors would like to thank Dr. Libin Liu in Swedish Institute of Metals Research for his helpful discussion. Special thanks should also be given to Mr. Shitong Li in Uni. of Shand
文摘The phase equilibrium relations of the ternary Ni-Cr-Zr system at 900℃ have been investigated by means of diffusion triple and electron probe microanalysis (EMPA) techniques. A series of tie lines and triangles have been determined, and the corresponding tentative isothermal section is presented based on the current information.
基金granted by the National Postdoctoral Science Foundation of ChinaResearch Foundation of Key Laboratory of High Energy Density Beam Processing Technology of China
文摘Heat treatment on the laser powder synthesized Ni20A130Fe intermetallic alloy was conducted. The microstructure and composition were analyzed by scanning electron microscopy. The results showed that heat treatment could promote the precipitation of the ductile phase and the coalescence and growth of the sub-crystal grains. These were desirable to improve the ambient ductility and the elevated-temperature strength of the Ni20A130Feintermetallic alloy.
基金Funded by the foundation for key projects in 2000 of the Science and Technology Committee of Chongqing China (No.2000-6214).
文摘Owing to both of its high carrier concentration and large band gap, ZnO:Al (ZAO) films which is an n-type degenerate semiconductor, exhibits low resistance and high transmittance in the visible range. This work studies the crystal structure, optical and electrical properties and preparation methods of ZAO films, and discusses the existing problems and application prospective of ZAO films.
文摘The Kokchetav Massif of northern Kazakhstan is a typelocality of occurrence of microdiamonds in ultrahighpressure metamorphic" rocks. It records continental subduction and exhumation from depths greater than 120 km and provides unparalleled insights into mantle dynamics, global material recycling and the processes responsible for the genesis and destruction of continent. Through the support of a US Civilian Development and Research Fund, a group of Russian, US, Taiwan Residents and Kazakhstan geologists visited the reconstructed 800-m underground gallery to conduct field survey and sample collections. This gallery provides a useful geologic laboratory for international community to undertake similar geotectonic or different ecological and environmental studies.
文摘Surface modification of calcium bicarbonate powder with isopropyl triisostearoyl titanate (TTS) by microwave-assisted heating was studied in the present work. The features of microwave treated powder show obvious superiority to those of powder samples treated by traditional surface modification method and of untreated calcium bicarbonate — in suspension turbidity, suction potential, contact angle with water, and mechanical properties of their composites with PVC resin.
