期刊文献+
共找到1,028篇文章
< 1 2 52 >
每页显示 20 50 100
MXene-based flexible pressure sensor with piezoresistive properties significantly enhanced by atomic layer infiltration 被引量:1
1
作者 Zilian Qi Tianwei Zhang +3 位作者 Xiao-Dong Zhang Qing Xu Kun Cao Rong Chen 《Nano Materials Science》 EI CAS CSCD 2023年第4期439-446,共8页
The flexible pressure sensor has been credited for leading performance including higher sensitivity,faster response/recovery,wider detection range and higher mechanical durability,thus driving the development of novel... The flexible pressure sensor has been credited for leading performance including higher sensitivity,faster response/recovery,wider detection range and higher mechanical durability,thus driving the development of novel sensing materials enabled by new processing technologies.Using atomic layer infiltration,Pt nanocrystals with dimensions on the order of a few nanometers can be infiltrated into the compressible lamellar structure of Ti3C2Tx MXene,allowing a modulation of its interlayer spacing,electrical conductivity and piezoresistive property.The flexible piezoresistive sensor is further developed from the Pt-infiltrated MXene on a paper substrate.It is demonstrated that Pt infiltration leads to a significant enhancement of the pressure-sensing performance of the sensor,including increase of sensitivity from 0.08 kPa^(-1)to 0.5 kPa^(-1),extension of detection limit from 5 kPa to 9 kPa,decrease of response time from 200 ms to 20 ms,and reduction of recovery time from 230 ms to 50 ms.The mechanical durability of the flexible sensor is also improved,with the piezoresistive performance stable over 1000 cycles of flexure fatigue.The atomic layer infiltration process offers new possibilities for the structure modification of MXene for advanced sensor applications. 展开更多
关键词 MXene Atomic layer deposition Pt infiltration PIEZORESISTIVE Flexible pressure sensor
下载PDF
Microstructure characteristics and thermodynamic properties of A357-SiCp/A357 layered composites prepared by semi-solid vacuum stirring suction casting
2
作者 Zhen-lin Zhang Ying Xiao +3 位作者 Jun Xu Feng-liang Tan Li Wang Min He 《China Foundry》 SCIE CAS CSCD 2023年第2期108-114,共7页
A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under differe... A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites. 展开更多
关键词 SEMI-SOLID vacuum stirring suction casting SiCp/A357 layered composites thermodynamic properties rheological casting
下载PDF
Wear Performance of Ni/ZrO_2 Infiltrated Composite Layer
3
作者 SUN Xianming YANG Guirong +3 位作者 SONG Wenming LI Jian MA Yin ZHOU You 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第1期73-78,共6页
The Ni/ZrO2 was used as raw materials to fabricate the surface infiltrated composite layer with 1-4 mm thickness on cast steel substrate through vacuum infiltrated casting technology. The microstructure indicated that... The Ni/ZrO2 was used as raw materials to fabricate the surface infiltrated composite layer with 1-4 mm thickness on cast steel substrate through vacuum infiltrated casting technology. The microstructure indicated that the infiltrated composite layer included surface composite layer and transition layer. Wear property was investigated under room temperature and 450 ~C. The results indicated that the abrasion volume of substrate was 8 times that of the infiltrated composite layer at room temperature. The friction coefficient of infiltrated composite layer decreased with the increasing load. The wear resistance of infiltrated composite layer with different ZrO2 contents had been improved obviously under high temperature. The friction coefficient of infiltrated composite layer was decreased comparing with that at room temperature. The oxidation, abrasive and fatigue abrasion was the main wear mechanism at room temperature. Oxidation abrasion, fatigue wear and adhesive wear dominated the wearin~ process under elevated temperature. 展开更多
关键词 Ni/ZrO2 infiltrated composite layer MICRO-STRUCTURE room temperature high temperature wear resistance
下载PDF
Effects of Typical Soil and Stratification Thickness on Water Infiltration Characteristics in Central Ningxia
4
作者 Tianwen ZHANG Wei CHEN +4 位作者 Xiaoying CHEN Rongjun ZHI Lin CHEN Haibo ZHANG Wei LIANG 《Meteorological and Environmental Research》 2024年第4期58-65,共8页
In order to compare the influence of different soil types and stratification on water infiltration capacity,two main types of soil in the desert steppe,sierozem(S)and aeolian sandy soil(A),were selected,and infiltrati... In order to compare the influence of different soil types and stratification on water infiltration capacity,two main types of soil in the desert steppe,sierozem(S)and aeolian sandy soil(A),were selected,and infiltration simulation tests were conducted on homogeneous soil and layered soil(layer thickness 5,10,and 20 cm),respectively.The results show that during the whole experiment,there was a small difference between S5A95(aeolian sandy soil 95 cm thick was covered with sierozem 5 cm thick)and S10A90(aeolian sandy soil 90 cm thick was covered with sierozem 10 cm thick)in the wetting front process,infiltration rate and cumulative infiltration,but there was a significant difference between S5A95 and S20A80(aeolian sandy soil 80 cm thick was covered with sierozem 20 cm thick).In the initial infiltration stage,there was no significant difference between A5S95(sierozem 95 cm thick was covered with aeolian sandy soil 5 cm thick)and A10S90(sierozem 90 cm thick was covered with aeolian sandy soil 10 cm thick).However,with the increase of infiltration time,the wetting front process,A5S95,A10S90 and A20S80 had significant differences in terms of wetting front process,infiltration rate and cumulative infiltration.The infiltration capacity of A was significantly higher than that of S.Combined with linear R 2 value and model parameters,the three infiltration models were comprehensively compared,and the fitting process and results of the general empirical model for the infiltration process of homogeneous soil and layered soil showed good results.Three models were used to simulate the water infiltration process of layered soil with different textures,and the order of the effect is as follows:general empirical model>Kostiakov model>Philip model.Soil type and layer thickness had a great influence on water infiltration process.When sierozem was covered with aeolian sandy soil 20 cm thick,the infiltration capacity was the best.As aeolian sandy soil was covered with sierozem 10 cm thick,the infiltration effect was the worst.Therefore,once coarse graying occurs on the surface of sierozem(the thickness of sand is more than 20 cm)or when the content of fine particles overlying aeolian sandy soil(the thickness of silt and clay soil is more than 10 cm)during ecological restoration is high,the soil hydrological characteristics will change significantly,which may lead to changes in vegetation types and even ecosystem structure. 展开更多
关键词 Soil type layer thickness Water infiltration Desert steppe
下载PDF
Effect of some parameters of formation on surface graphite-bronze composite layer prepared by vacuum infiltration casting technique 被引量:1
5
作者 杨贵荣 郝远 +1 位作者 宋文明 马颖 《广东有色金属学报》 2005年第2期510-517,共8页
Surface composite up to 3.0 mm in thickness with compact microstructure was fabricated successfully via vacuum infiltration casting technique on the bronze substrate under the optimum experimental conditions: the vacu... Surface composite up to 3.0 mm in thickness with compact microstructure was fabricated successfully via vacuum infiltration casting technique on the bronze substrate under the optimum experimental conditions: the vacuum degree of -0.08 MPa, pouring temperature of 1220℃, grain size of 0.20-0.24 mm, preheating temperature of 180℃. The preform was mainly composed of graphite particles and binder NJB (self-fabricated binder). The vacuum degree, pouring temperature, preheating temperature and grain size during infiltration casting play an important role on the process of forming the surface composite. The results show that three cases are obtained in the vacuum infiltration casting technique: no infiltration, partial infiltration and full infiltration. The main reason of no infiltration is that the vacuum degree is not enough so that the force acting on the liquid metal is lower than the resistance due to the surface tension and the pouring temperature is somewhat low. Partial infiltration is because of somewhat lower vacuum degree and pouring temperature. Full desired infiltration is on account of suitable infiltration casting conditions, such as vacuum degree, pouring temperature, grain size and preheating temperature. The influencing effect of vacuum degree is most obvious for the formation of surface composite, then pouring temperature and particle size. The infiltration mechanism is discussed on the bases of the different processing conditions. 展开更多
关键词 石墨 青铜 复合材料 渗透铸造技术
下载PDF
Preparation of open-celled aluminum foams by counter-gravity infiltration casting 被引量:5
6
作者 HUO Deng-wei YANG Juan +2 位作者 ZHOU Xiang-yang WANG Hui ZHANG Tai-kang 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第1期85-89,共5页
A novel counter-gravity infiltration casting device and corresponding fabricating process for producing open-celled aluminum foams were presented. The experimental results show that defects such as insufficient or exc... A novel counter-gravity infiltration casting device and corresponding fabricating process for producing open-celled aluminum foams were presented. The experimental results show that defects such as insufficient or excessive infiltrating can hardly be found in the foam samples prepared by counter-gravity infiltration casting. The foam materials exhibit excellent mechanical properties. The void content strongly affects the mechanical properties of aluminum foams. The yield stress and plateau stress significantly increase with the decrease of void content. Raising pre-heating temperature and increasing packing pressure are effective to lower the void content in aluminum foams. 展开更多
关键词 open-celled aluminum foams counter-gravity infiltration casting void content mechanical properties
下载PDF
Surface composites fabricated by vacuum infiltration casting technique 被引量:3
7
作者 Guirong Yang Yuan Hao +2 位作者 Wenming Song Jinjun Lii Ying Ma 《Journal of University of Science and Technology Beijing》 CSCD 2005年第5期455-459,共5页
Alumina (Al2O3) particles reinforced copper matrix surface composites were fabricated on the bronze substrate using the vacuum infiltration casting technique. Three cases were obtained in the vacuum infiltration cas... Alumina (Al2O3) particles reinforced copper matrix surface composites were fabricated on the bronze substrate using the vacuum infiltration casting technique. Three cases were obtained in the vacuum infiltration casting technique: no infiltration, partial infiltration and full infiltration (the thickness of preforms do not exceed 3.5mm). The reason of no infiltration is that the vacuum degree is not enough so that the force acting on the liquid metal is lower than the resistance due to the surface tension. Partial infiltration is because of somewhat lower vacuum degree and pouring temperature. Full desired infiltration is on account of suitable infiltration casting conditions, such as vacuum degree, pouring temperature, grain size and preheating temperature of the preform. The most important factor of affecting formation of surface composites is the vacuum degree, then pouring temperature and particle size. The infiltration mechanism was discussed on the bases of different processing conditions. The surface composite up to 3.5 mm in thickness with uniformly distributed Al2O3 particles could be fabricated via the vacuum infiltration casting technique. 展开更多
关键词 ALUMINA vacuum infiltration casting surface composite PREFORM
下载PDF
Thermal properties of open-celled aluminum foams prepared by two infiltration casting methods 被引量:2
8
作者 王辉 周向阳 +2 位作者 龙波 文康 杨焘 《Journal of Central South University》 SCIE EI CAS 2014年第7期2567-2571,共5页
Contrastive research was carried out to study the thermal properties of open-celled aluminum foams prepared by counter-gravity infiltration casting system and the traditional process respectively.The experimental resu... Contrastive research was carried out to study the thermal properties of open-celled aluminum foams prepared by counter-gravity infiltration casting system and the traditional process respectively.The experimental results show that the thermal conductivity coefficients of aluminum foams prepared by two different infiltration methods have similar increasing trend with the increase of particle size;along with the reducing porosity,the thermal conductivity coefficients will be enhanced oppositely.However,with the same particle size,the open-celled aluminum foam prepared by the former method has a higher thermal conductivity coefficient obviously.It is largely because that the sample prepared by counter-gravity infiltration casting has a lower void content and better dense crystallization of metal-matrix after the constant pressure process. 展开更多
关键词 open-celled aluminum foams counter-gravity infiltration casting thermal conductivity coefficient particle size POROSITY
下载PDF
IN SITU GRADIENT DOUBLE-LAYER COMPOSITES OF Al-Fe ALLOY BY CENTRIFUGAL CASTING 被引量:1
9
作者 Wang, Qudong 《中国有色金属学会会刊:英文版》 EI CSCD 1997年第1期126-131,共6页
INSITUGRADIENTDOUBLELAYERCOMPOSITESOFAlFeALLOYBYCENTRIFUGALCASTING①WangQudong,JinJunzeResearchCenterofFoun... INSITUGRADIENTDOUBLELAYERCOMPOSITESOFAlFeALLOYBYCENTRIFUGALCASTING①WangQudong,JinJunzeResearchCenterofFoundryEnginering,Dal... 展开更多
关键词 in SITU COMPOSITES GRADIENT COMPOSITES double layer COMPOSITES Al Fe ALLOY CENTRIFUGAL castING
下载PDF
Preparation of big size open-cell aluminum foam board using infiltration casting 被引量:1
10
作者 wang Lucai Chen Yuyong +2 位作者 Wang Fang Wu Jianguo You Xiaohong 《China Foundry》 SCIE CAS 2008年第4期240-243,共4页
This paper presents an infiltration casting technique for manufacturing big size open-cell aluminum foam boards. The principle and key technologies of infiltration casting are also analyzed. Based on the previous prac... This paper presents an infiltration casting technique for manufacturing big size open-cell aluminum foam boards. The principle and key technologies of infiltration casting are also analyzed. Based on the previous practice of the small size aluminum foam production, the die for preparing big size aluminum foam boards is designed and manufactured. The experiments on aluminum boards of 300 mm × 300 mm × (20-75) mm, with the pore size ranging from 1.0 to 3.2 mm and average porosity of 60%, have been performed. The experimental results show that a reliable infiltration process depends critically on the pouring temperature of the molten AI-alloy, the preheated temperature of the mould and salt particles and vacuum. Current research explores the possibility of large-scale manufacturing and application of the aluminum foams. 展开更多
关键词 infiltration casting aluminum foam BOARD
下载PDF
Experimental investigation on rainfall infiltration and solute transport in layered porous and fractured media 被引量:1
11
《Journal of Coal Science & Engineering(China)》 2012年第1期29-34,共6页
Layered structures with upper porous and lower fractured media are widely distributed in the world. An experimen- tal investigation on rainfall infiltration and solute transport in such layered structures can provide ... Layered structures with upper porous and lower fractured media are widely distributed in the world. An experimen- tal investigation on rainfall infiltration and solute transport in such layered structures can provide the necessary foundation for effectively preventing and forecasting water bursting in mines, controlling contamination of mine water, and accomplishing ecological restoration of mining areas. A typical physical model of the layered structures with porous and fractured media was created in this study. Then rainfall infiltration experiments were conducted after salt solution was sprayed on the surface of the layered structure. The volumetric water content and concentration of chlorine ions at different specified positions along the profile of the experiment system were measured in real-time. The experimental results showed that the lower fractured media, with a considerably higher permeability than that of the upper porous media, had significant effects on preventing water infil- tration. Moreover, although the porous media were homogeneous statistically in the whole domain, spatial variations in the features of effluent concentrations with regards to time, or so called breakthrough curves, at various sampling points located at the horizontal plane in the porous media near the porous-fractured interface were observed, indicating the diversity of solute transport at small scales. Furthermore, the breakthrough curves of the outflow at the bottom, located beneath the underlying fractured rock, were able to capture and integrate features of the breakthrough curves of both the upper porous and fractured media, which exhibited multiple peaks, while the peak values were reduced one by one with time. 展开更多
关键词 rainfall infiltration solute transport layered porous and fractured media lab experiment breakthrough curves
下载PDF
Mg alloy surface alloying layer fabricated through evaporative pattern casting technology
12
作者 陈东风 董选普 +1 位作者 张雄 樊自田 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第12期2240-2245,共6页
The influencing factors of surface alloying layer by evaporative pattern casting technology were investigated.A certain thickness alloying layer was formed on the surface of Mg-alloy matrix when the pouring temperatur... The influencing factors of surface alloying layer by evaporative pattern casting technology were investigated.A certain thickness alloying layer was formed on the surface of Mg-alloy matrix when the pouring temperature was 780°C with different vacuum degree and alloying powder size.The surface layer microstructure,micro area composition of the new phase formed on the matrix and the composition characteristics on the surface layer were examined by SEM and element scanning.The results show that the content of aluminum increases greatly on the surface layer.The micro-hardness of alloyed layer has a more obvious increase compared with that of the matrix.The size of alloying element and the vacuum degree are the key factors influencing the alloying layer,with the increase of element powder size from 0.074 to 0.15 mm and vacuum degree from 0.04 to 0.06 MPa,the surface alloying effect becomes better. 展开更多
关键词 Mg alloy evaporative pattern casting surface alloying layer micro-hardness
下载PDF
A dynamic infiltration technique to synthesize nanolayered cathodes for high performance and robust solid oxide fuel cells
13
作者 Saeed Ur Rehman Ho-Seon Song +7 位作者 Hye-Sung Kim Muhammad Haseeb Hassan Dong-Woo Joh Rak-Hyun Song Tak-Hyoung Lim Jong-Eun Hong Seok-Joo Park Seung-Bok Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第7期201-210,I0006,共11页
Solution infiltration is a popular technique for the surface modification of solid oxide fuel cell(SOFC)cathodes.However,the synthesis of nanostructured SOFC cathodes by infiltration is a tedious process that often re... Solution infiltration is a popular technique for the surface modification of solid oxide fuel cell(SOFC)cathodes.However,the synthesis of nanostructured SOFC cathodes by infiltration is a tedious process that often requires several infiltration and high temperature(≥500℃)calcination cycles.Moreover,fabricating large-area nanostructured cathodes via infiltration still requires serious attention.Here,we propose a facile and scalable urea assisted ultrasonic spray infiltration technique for nanofabrication of SOFC cathodes.It is demonstrated that by using urea as a precipitating agent,the calcination after each infiltration cycle can be omitted and the next infiltration can be performed just after a drying step(≤100℃).Finally,the precipitates can be converted into a desired catalyst phase in single calcination thus,a nanostructured cathode can be fabricated in a much faster manner.It is also shown that the low calcination temperature of the cathode(≤900℃)can produce highly durable SOFC performance even without employing a Ce_(0.9)Gd_(0.1)O_(2)(GDC)diffusion barrier layer which provides the ease of SOFC fabrication.While coupling with an ultrasonic spray technique,the urea assisted infiltration can be scaled up for any desired cathode area.La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3) nanolayered cathode was fabricated and it was characterized by scanning electron microscope(SEM),X-ray diffraction(XRD),and transmission electron microscopy(TEM)techniques.SEM showed the formation of a nanolayer cathode just after 5 cycles of the urea assisted infiltration while the XRD and TEM confirmed the phase and stoichiometric uniformity of the 100 nm cathode nanolayer.The effectiveness of the newly developed technique was further verified by the stable operation of a GDC buffer layer free SOFC having an active cathode area of 25 cm^(2) during a 1200 h durability test.The research outcomes propose urea assisted ultrasonic spray infiltration as a facile,scalable,and commercially viable method for the fabrication of durable nanostructured SOFC cathodes. 展开更多
关键词 Solid oxide fuel cell(SOFC) Cathode infiltrATION NANOlayer Nanofabrication GDC barrier layer free SOFC
下载PDF
Fabrication and compressive behavior of open-cell aluminum foams via infiltration casting using spherical CaCl_(2) space-holders
14
作者 Tan Wan Gang-qiang Liang +2 位作者 Zhao-ming Wang Can-xu Zhou Yuan Liu 《China Foundry》 SCIE CAS 2022年第2期89-98,共10页
The infiltration casting fabrication process based on spherical CaCl_(2) space-holders and the compressive behavior including the mechanical performance and energy absorption capacity of open-cell aluminum foams were ... The infiltration casting fabrication process based on spherical CaCl_(2) space-holders and the compressive behavior including the mechanical performance and energy absorption capacity of open-cell aluminum foams were investigated.Open-cell aluminum foams with different porosities in the range of 63.1%to 87.3%can be fabricated by adjusting compression ratios of CaCl_(2) preforms prepared by precision hot-pressing.The compression tests show that a strain-hardening phenomenon always occurs especially for open-cell aluminum foam with low porosity,resulting in the inclining stress-strain curve in the plateau region.The energy absorption capacity of open-cell aluminum foam decreases with increasing porosity when compared at the same strain.However,when compared at a given stress,each foam can absorb the maximal energy among the five foams in a special stress range.Additionally,open-cell aluminum foam possesses the maximum energy absorption efficiency at its optimum operating stress.At this stress condition,the foam can absorb the highest energy compared with other foams at the same stress point.The optimum operating stress and the corresponding maximal energy absorption decrease with increasing the porosity.The optimum operating stress for energy absorption can also be determined similarly when taking into consideration of the lightweight extent of foams. 展开更多
关键词 open-cell aluminum foam CaCl_(2)space-holder infiltration casting energy absorption
下载PDF
Interface characteristics and wear resistance of Ni-B_(4)C plated ZTA reinforced high chromium cast iron composite
15
作者 Ke-liang Li Wei Li Yan-liang Yi 《China Foundry》 SCIE CAS CSCD 2023年第3期253-262,共10页
A chemical composite plating of Ni-B_(4)C was used to prepare the surface-modified zirconia toughened alumina(ZTA)ceramic particles.The ceramic preforms were prepared by the plated ZTA and sodium silicate solution bin... A chemical composite plating of Ni-B_(4)C was used to prepare the surface-modified zirconia toughened alumina(ZTA)ceramic particles.The ceramic preforms were prepared by the plated ZTA and sodium silicate solution binder,followed by casting infiltration to prepare the ZTA particles reinforced high chromium cast iron(HCCI)composites.The result reveals that a distinct interface layer forms at the ZTA/HCCI interface,which consists of phases of ZrB_(2),FeB,Fe_(2)B,and NaSiO_(4).The interfacial wettability between ZTA and HCCI is improved by the diffusion and reaction of Ni and B_(4)C.The wear test reveals that the Ni-B_(4)C plated ZTA particles can effectively improve the wear resistance of the ZTA/HCCI composite,and the wear rate of the composite is decreased to 11.6%of HCCI. 展开更多
关键词 ZTA COMPOSITE high chromium cast iron interface layer three-body abrasive wear
下载PDF
Layer Structure Analysis of Low-Carbon Steel Containing Rare Earth by High-Temperature Carburizing of Liquid Cast-Iron
16
作者 谌岩 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第S1期130-133,共4页
The layer structure of low-carbon steel containing RE by high-temperature (T>1200 ℃) carburizing of liquid cast-iron was studied and the diffusion activation energy of carbon was calculated by metallographic micr... The layer structure of low-carbon steel containing RE by high-temperature (T>1200 ℃) carburizing of liquid cast-iron was studied and the diffusion activation energy of carbon was calculated by metallographic microscpe, chemical analysis etc. The result shows that the technology of carburizing in liquid cast-iron can expedite caburization distinctly and changes the carburizing layer structure. The carburizing rate is 60~80 times of that of the traditional technology, and there is about 43% decrease in the activation energy compared with gas-carburization. In outer structure layer, cementite is formed simultaneously both on the crystal boundary reticularly and inside the crystal grains stripedly. In inner carburizing layer, there is undissolved blocky ferrite in reticular cementite. Besides, rare earth element can expedite carburization process. 展开更多
关键词 low-carbon steel high-temperature carburizing of liquid cast-iron layer structure rare earths
下载PDF
流程生产风险防控的功能安全完整性
17
作者 张建荣 张伟 +1 位作者 张充 赵挺生 《科学技术与工程》 北大核心 2024年第9期3923-3929,共7页
为提升流程生产安全管理水平,降低事故发生概率,提出了生产过程中风险防控的功能安全完整性分析方法,并结合钢铁连铸场景进行验证。首先评估流程生产中主要事故类型的危险程度和确定其可接受频率标准;运用保护层分析法计算作业现场高危... 为提升流程生产安全管理水平,降低事故发生概率,提出了生产过程中风险防控的功能安全完整性分析方法,并结合钢铁连铸场景进行验证。首先评估流程生产中主要事故类型的危险程度和确定其可接受频率标准;运用保护层分析法计算作业现场高危险性事故发生的真实概率,通过与可接受频率比较,判断是否需要新增防护措施;运用蒙特卡洛-马尔可夫模型验证新增防护措施的功能安全完整性等级。以大冶特钢炼钢转炉厂连铸作业区为例,结果表明:研究区内存在熔融物爆炸、火灾和中毒窒息3类高危险性事故隐患,且熔融物爆炸事故的人员伤亡后果为不可接受,需新增功能安全完整性等级为2级的防护措施;设计了防爆炸保护系统,其失效概率为4.37×10-3,满足功能安全完整性等级要求。 展开更多
关键词 功能安全 钢铁连铸 安全完整性等级 保护层分析 马尔可夫
下载PDF
Ti预处理的SiC_(f)/SiC与镍基高温合金复合铸件的界面组织与强度
18
作者 林国标 朱付虎 赵斯文 《材料工程》 EI CAS CSCD 北大核心 2024年第2期164-171,共8页
由SiC_(f)/SiC复合材料与K403镍基高温合金熔体制备的一体化铸件,冷却到室温时会出现自行断裂。通过采用Ti粉埋覆包渗工艺在1100℃下对SiC_(f)/SiC表面进行预处理,并在适当工艺下与K403镍基高温合金熔体进行陶瓷型精密铸造,成功实现SiC_... 由SiC_(f)/SiC复合材料与K403镍基高温合金熔体制备的一体化铸件,冷却到室温时会出现自行断裂。通过采用Ti粉埋覆包渗工艺在1100℃下对SiC_(f)/SiC表面进行预处理,并在适当工艺下与K403镍基高温合金熔体进行陶瓷型精密铸造,成功实现SiC_(f)/SiC与K403镍基高温合金的一体化成形和界面的牢固结合。结果表明:Ti预处理层平均厚度为17μm左右,Ti向SiC_(f)/SiC渗透、扩散和反应,形成含TiC,Ti3SiC2,Ti5Si3Cx,SiC相的显微组织;经过与高温镍基金属液复合铸造后,预处理层演变成厚约120μm的界面反应层,其典型界面组织为Ni2Si+C+Al4C3+MC(M主要含Ti及少量的Cr,Mo,W)。预处理层的存在减轻Ni与SiC的有害石墨化反应,缓解高温金属液对SiC_(f)/SiC的热冲击,形成的界面反应层降低热膨胀系数失配造成的热应力,使得SiC_(f)/SiC与K403一体化铸件结合界面的室温剪切强度达到63.5 MPa。 展开更多
关键词 SiC_(f)/SiC K403 镍基高温合金 一体化铸造 复合铸造 Ti预处理层
下载PDF
原位生成周期性层片结构镀层及其在NaCl溶液中的腐蚀形貌
19
作者 张先满 李星涛 +2 位作者 季坤鹏 陈再雨 罗洪峰 《材料导报》 EI CAS CSCD 北大核心 2024年第12期162-168,共7页
金属在海洋氯离子环境中极易发生腐蚀,并造成巨大的经济损失。通过制备新型Fe-Cr-B铸钢,采用热浸镀铝-扩散热处理原位生成含有周期性层片结构(PLSs)的镀层,并利用扫描电子显微镜(SEM)、电子探针X射线显微分析仪(EPMA)等手段研究了该镀... 金属在海洋氯离子环境中极易发生腐蚀,并造成巨大的经济损失。通过制备新型Fe-Cr-B铸钢,采用热浸镀铝-扩散热处理原位生成含有周期性层片结构(PLSs)的镀层,并利用扫描电子显微镜(SEM)、电子探针X射线显微分析仪(EPMA)等手段研究了该镀层的组织结构及其在3.5%(质量分数)NaCl溶液中的腐蚀行为。结果表明,该铸钢的显微组织主要由粗大的初生(Cr,Fe)_(2)B及α-Fe组成;热浸镀铝时在(Cr,Fe)_(2)B/Al界面上生成由FeAl3和Cr-Al-B相组成的PLSs,在α-Fe/Al界面上生成FeAl3;扩散热处理使得反应层增厚,且PLSs在反应层中大量生成;相比FeAl3,镀层中的PLSs在腐蚀过程中充当阳极优先腐蚀,并表现出腐蚀各向异性,尤其是其中的Cr-Al-B相可明显阻挡氯离子腐蚀,使得PLSs通过延长腐蚀路径进而提高镀层的耐氯离子腐蚀性能。 展开更多
关键词 Fe-Cr-B铸钢 热浸镀铝 扩散热处理 周期性层片结构(PLSs) 氯离子
下载PDF
马鞍山长江公铁大桥主航道桥中塔下横梁施工关键技术
20
作者 刘爱林 徐敏 王伟 《世界桥梁》 北大核心 2024年第4期29-34,共6页
马鞍山长江公铁大桥主航道桥Z4号中塔采用空间四肢A形钢-混组合塔,横向两塔肢间设下横梁,下横梁间设3道系梁,纵向两塔肢间不设置横梁。下横梁采用支架法分层浇筑施工。下横梁施工支架采用落地式钢管支架配套模板体系,受力性能满足要求;... 马鞍山长江公铁大桥主航道桥Z4号中塔采用空间四肢A形钢-混组合塔,横向两塔肢间设下横梁,下横梁间设3道系梁,纵向两塔肢间不设置横梁。下横梁采用支架法分层浇筑施工。下横梁施工支架采用落地式钢管支架配套模板体系,受力性能满足要求;通过有限元计算比选下横梁混凝土分层浇筑方案并进行优化,采取(5.5+2.5)m分层方案,上、下层混凝土分别分为2块、3块分层分块浇筑;通过低温升、易泵送、高抗裂的C60混凝土研制、下横梁与塔柱倒弧结合面抗裂措施优化、分块间接缝构造形式及施工工艺优化、下横梁与系梁混凝土浇筑施工组织优化、混凝土温度智能化监控、预应力束张拉时机控制等混凝土防裂措施,有效解决了下横梁大体积混凝土易开裂的难题。 展开更多
关键词 斜拉桥 钢-混组合塔 下横梁 施工支架 分层分块浇筑法 混凝土防裂措施 施工技术
下载PDF
上一页 1 2 52 下一页 到第
使用帮助 返回顶部