A novel high nitrogen medium-entropy alloy CrCoNiN, which had higher strength and slightly lower ductility than CrCoNi alloy, was successfully manufactured by pressurized metallurgy.The microstructure and corrosion be...A novel high nitrogen medium-entropy alloy CrCoNiN, which had higher strength and slightly lower ductility than CrCoNi alloy, was successfully manufactured by pressurized metallurgy.The microstructure and corrosion behaviour were investigated by microscopic, electrochemical and spectroscopic methods. The results indicated that nitrogen existed in the form of Cr2N precipitates and uniformly distributed N atoms, and nitrogen alloying significantly refined the grain size. Besides, nitrogen enriched on the outmost surface of passive film and metal/film interface as ammonia （NH3 and NH4^＋） and CrN, respectively. The significant improvement of corrosion resistance of CrCoNiN was attributed to the lower metastahle pitting susceptibility together with thicker, less defective and more compact passive film.展开更多
The effects of the basal and top-dressing nitrogen (N) on N uptake and translocation, N utilization efficiency, grain yieldand quality of medium-gluten winter wheat Yangmai 10 were studied from 2000 to 2002. The main ...The effects of the basal and top-dressing nitrogen (N) on N uptake and translocation, N utilization efficiency, grain yieldand quality of medium-gluten winter wheat Yangmai 10 were studied from 2000 to 2002. The main results were as follows.Nitrogen content and nitrogen accumulation in plant at maturity increased with the amount of N application. Grain proteincontent and wet gluten content were significantly correlated with applied N. There was a significantly positive correlationbetween nitrogen accumulation before anthesis (NBA) and basal N fertilizer, and between nitrogen accumulation afteranthesis (NAA) and top-dressing N. N accumulated in grains was significantly correlated to NBA, NAA and N translocationfrom vegetative organs after anthesis (NTVA). NBA was significantly correlated with N application, but NAA and NTVAhad a quadratic curve correlation with applied N. N fertilizer use efficiency (NUE) had a quadratic curve correlation withapplied N, and the NUE was high when basal and top-dressing N was equally applied. For the medium-gluten wheatYangmai 10 under the same N application ratio, there was a N-regulating effect when the N application was less than266.55 kg ha-1, a stagnation of yield and quality when N application ranged from 266.55 to 309.08 kg ha-1, and an excessiveN application when the N application rate was greater than 309.08 kg ha-1. Under the conditions of this experiment, theprecise N application is 220-270 kg ha-1 with basal and top-dressing N equally used when a grain yield of more than 6 750kg ha-1, protein content higher than 12%, wet gluten content more than 30% and NUE greater than 40% could be obtained.展开更多
Goal: obtaining of composite in the SiC-SiAlON system with the metal thermal method in the nitrogen medium. Method: SiALON-s are solid metal oxide solutions in nitrides. Area of their presence is considered in four-co...Goal: obtaining of composite in the SiC-SiAlON system with the metal thermal method in the nitrogen medium. Method: SiALON-s are solid metal oxide solutions in nitrides. Area of their presence is considered in four-component system-Si3N4-ALN-AL2O3-SiO2. In the present paper SiALON-containing composite was obtained through alum-thermal process in the nitrogen medium on the base of Geopolymer (kaolin and pologycley-Ukraine), SiC, aluminum nano-powder and Si powder with small additives of perlite (Aragatz, Armenia) by the reactive baking method. The advantage of this method is that compounds, which are newly formed thanks to interaction going on at thermal treatment: Si3N4, Si, AlN are active, which contributes to SiALON formation at relatively low temperature, at 1250°C - 1300°C. Results-β-SiAlON was formed at the sintering of SiC-aluminium and silicium powder, geopolymer at 1450°C. Porosity of carbide SiAlON composite obtained by reactive sintering, according to water absorption, equals to 13% - 15%. The samples were fragmented in a jaw-crusher and were powdered in attrition mill till micro-powder dispersion was obtained. Then samples were hot-pressed at 1620°C under 30 MPa pressure. Hold-time at the final temperature was 8 min. Sample water absorption, according to porosity, was less than 0.4%. Further studies were continued on these samples. Conclusion: the paper offers processes of formation of SiC-SiAlON composites and their physical and technical properties. Phase composition of the composites was studied by X-ray diffraction method, while the structure was studied by the use of optic and electron microscope. Electric properties showed that the specimen A obtained by hot-compression is characterized by 2 signs lower resistance than the porous material B, which was used to receive this specimen. Probably this should be connected with transition of the reactively baked structure of the hot-compressed material into compact structure. Obtained materials are used in protecting jackets of thermo couples used for melted metal temperature measuring (18 - 20 measuring) and for constructions used for placing objects in factory furnaces.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51434004,U1435205,51774074)the Transformation Project of Major Scientific and Technological Achievements in Shenyang(Grant No.Z17-5-003)
文摘A novel high nitrogen medium-entropy alloy CrCoNiN, which had higher strength and slightly lower ductility than CrCoNi alloy, was successfully manufactured by pressurized metallurgy.The microstructure and corrosion behaviour were investigated by microscopic, electrochemical and spectroscopic methods. The results indicated that nitrogen existed in the form of Cr2N precipitates and uniformly distributed N atoms, and nitrogen alloying significantly refined the grain size. Besides, nitrogen enriched on the outmost surface of passive film and metal/film interface as ammonia （NH3 and NH4^＋） and CrN, respectively. The significant improvement of corrosion resistance of CrCoNiN was attributed to the lower metastahle pitting susceptibility together with thicker, less defective and more compact passive film.
基金supported by Foundation for University Key Teacher by the Ministry of Education of China(GG-901-11117-1003)the Research Fund from Jiangsu Province of China(BE2001333).
文摘The effects of the basal and top-dressing nitrogen (N) on N uptake and translocation, N utilization efficiency, grain yieldand quality of medium-gluten winter wheat Yangmai 10 were studied from 2000 to 2002. The main results were as follows.Nitrogen content and nitrogen accumulation in plant at maturity increased with the amount of N application. Grain proteincontent and wet gluten content were significantly correlated with applied N. There was a significantly positive correlationbetween nitrogen accumulation before anthesis (NBA) and basal N fertilizer, and between nitrogen accumulation afteranthesis (NAA) and top-dressing N. N accumulated in grains was significantly correlated to NBA, NAA and N translocationfrom vegetative organs after anthesis (NTVA). NBA was significantly correlated with N application, but NAA and NTVAhad a quadratic curve correlation with applied N. N fertilizer use efficiency (NUE) had a quadratic curve correlation withapplied N, and the NUE was high when basal and top-dressing N was equally applied. For the medium-gluten wheatYangmai 10 under the same N application ratio, there was a N-regulating effect when the N application was less than266.55 kg ha-1, a stagnation of yield and quality when N application ranged from 266.55 to 309.08 kg ha-1, and an excessiveN application when the N application rate was greater than 309.08 kg ha-1. Under the conditions of this experiment, theprecise N application is 220-270 kg ha-1 with basal and top-dressing N equally used when a grain yield of more than 6 750kg ha-1, protein content higher than 12%, wet gluten content more than 30% and NUE greater than 40% could be obtained.
文摘Goal: obtaining of composite in the SiC-SiAlON system with the metal thermal method in the nitrogen medium. Method: SiALON-s are solid metal oxide solutions in nitrides. Area of their presence is considered in four-component system-Si3N4-ALN-AL2O3-SiO2. In the present paper SiALON-containing composite was obtained through alum-thermal process in the nitrogen medium on the base of Geopolymer (kaolin and pologycley-Ukraine), SiC, aluminum nano-powder and Si powder with small additives of perlite (Aragatz, Armenia) by the reactive baking method. The advantage of this method is that compounds, which are newly formed thanks to interaction going on at thermal treatment: Si3N4, Si, AlN are active, which contributes to SiALON formation at relatively low temperature, at 1250°C - 1300°C. Results-β-SiAlON was formed at the sintering of SiC-aluminium and silicium powder, geopolymer at 1450°C. Porosity of carbide SiAlON composite obtained by reactive sintering, according to water absorption, equals to 13% - 15%. The samples were fragmented in a jaw-crusher and were powdered in attrition mill till micro-powder dispersion was obtained. Then samples were hot-pressed at 1620°C under 30 MPa pressure. Hold-time at the final temperature was 8 min. Sample water absorption, according to porosity, was less than 0.4%. Further studies were continued on these samples. Conclusion: the paper offers processes of formation of SiC-SiAlON composites and their physical and technical properties. Phase composition of the composites was studied by X-ray diffraction method, while the structure was studied by the use of optic and electron microscope. Electric properties showed that the specimen A obtained by hot-compression is characterized by 2 signs lower resistance than the porous material B, which was used to receive this specimen. Probably this should be connected with transition of the reactively baked structure of the hot-compressed material into compact structure. Obtained materials are used in protecting jackets of thermo couples used for melted metal temperature measuring (18 - 20 measuring) and for constructions used for placing objects in factory furnaces.
