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Determining casting defects in near-net shape casting aluminum parts by computed tomography
Jiehua LI, Bernd OBERDORFER, Daniel HABE, Peter SCHUMACHER
《机械工程前沿(英文)》 2018年 第13卷 第1期 页码 48-52 doi: 10.1007/s11465-018-0493-y
Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.
关键词: near-net shape casting aluminum parts casting defects low pressure die casting die casting semi-solid casting computed tomography
Interfacial heat transfer coefficient between metal and die during high pressure die casting process
GUO Zhipeng, XIONG Shoumei, CHO SangHyun, CHOI JeongKil
《机械工程前沿(英文)》 2007年 第2卷 第3期 页码 283-287 doi: 10.1007/s11465-007-0049-z
Novel technologies for the lost foam casting process
Wenming JIANG, Zitian FAN
《机械工程前沿(英文)》 2018年 第13卷 第1期 页码 37-47 doi: 10.1007/s11465-018-0473-2
Lost foam casting (LFC) is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the Al and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting techno- logy; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thin-wall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the Al/Mg and Al/Al bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.
关键词: LFC under vacuum and low pressure vibration solidification pressure solidification expendable shell casting bimetallic castings
An energy consumption prediction approach of die casting machines driven by product parameters
《机械工程前沿(英文)》 2021年 第16卷 第4期 页码 868-886 doi: 10.1007/s11465-021-0656-0
关键词: die casting machine energy consumption prediction product parameters
Ultrasonic measurement of tie-bar stress for die-casting machine
《机械工程前沿(英文)》 doi: 10.1007/s11465-021-0663-1
Roham RAFIEE, Hossein RASHEDI, Shiva REZAEE
《结构与土木工程前沿(英文)》 2020年 第14卷 第6期 页码 1349-1358 doi: 10.1007/s11709-020-0650-3
关键词: composite pressure vessel low-velocity impact failure theoretical solution progressive damage modeling
《化学科学与工程前沿(英文)》 2022年 第16卷 第5期 页码 699-708 doi: 10.1007/s11705-021-2093-3
关键词: layer-by-layer self-assembly single bilayer nanofiltration membrane desalination
Using mRNA to investigate the effect of low-pressure ultraviolet disinfection on the viability of
Chao Yang, Wenjun Sun, Xiuwei Ao
《环境科学与工程前沿(英文)》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1111-x
UV can induce damages on mRNA consistently among different genes. SOS response was more active after UV treatment. Programmed cell death was not found to be more active after UV treatment.
关键词: UV disinfection Viability mRNA SOS response Programmed cell death
Study of the robustness of a low-temperature dual-pressure process for removal of CO
Stefania Moioli, Laura A. Pellegrini, Paolo Vergani, Fabio Brignoli
《化学科学与工程前沿(英文)》 2018年 第12卷 第2期 页码 209-225 doi: 10.1007/s11705-017-1688-1
关键词: CO2 capture innovative process cryogenic distillation dynamic simulation solid-liquid-vapor equilibrium
Hong SUN,Min SUN,Yaobin ZHANG,Xie QUAN
《环境科学与工程前沿(英文)》 2015年 第9卷 第4期 页码 591-595 doi: 10.1007/s11783-014-0694-5
关键词: catalytic ozonation reactive red X-3B ceramic honeycomb hydroxyl radical (OH·)
Novel casting processes for single-crystal turbine blades of superalloys
Dexin MA
《机械工程前沿(英文)》 2018年 第13卷 第1期 页码 3-16 doi: 10.1007/s11465-018-0475-0
This paper presents a brief review of the current casting techniques for single-crystal (SC) blades, as well as an analysis of the solidification process in complex turbine blades. A series of novel casting methods based on the Bridgman process were presented to illustrate the development in the production of SC blades from superalloys. The grain continuator and the heat conductor techniques were developed to remove geometry-related grain defects. In these techniques, the heat barrier that hinders lateral SC growth from the blade airfoil into the extremities of the platform is minimized. The parallel heating and cooling system was developed to achieve symmetric thermal conditions for SC solidification in blade clusters, thus considerably decreasing the negative shadow effect and its related defects in the current Bridgman process. The dipping and heaving technique, in which thin-shell molds are utilized, was developed to enable the establishment of a high temperature gradient for SC growth and the freckle-free solidification of superalloy castings. Moreover, by applying the targeted cooling and heating technique, a novel concept for the three-dimensional and precise control of SC growth, a proper thermal arrangement may be dynamically established for the microscopic control of SC growth in the critical areas of large industrial gas turbine blades.
关键词: superalloy investment casting Bridgman process directional solidification single crystal turbine blade
Spray characteristics of high-pressure swirl injector fueled with alcohol
WANG Xibin, CHEN Wansheng, GAO Jian, JIANG Deming, HUANG Zuohua
《能源前沿(英文)》 2007年 第1卷 第1期 页码 105-112 doi: 10.1007/s11708-007-0012-z
Hybrid forming mechanism of patternless casting and laser cladding
Zhongde SHAN, Fuzhen SUN, Yang LIU
《机械工程前沿(英文)》 2019年 第14卷 第4期 页码 393-401 doi: 10.1007/s11465-019-0550-1
关键词: patternless casting laser cladding hybrid forming rapid tooling
Wei Hou, Qingjun Zhang, Aiwu Zeng
《化学科学与工程前沿(英文)》 2021年 第15卷 第5期 页码 1169-1184 doi: 10.1007/s11705-020-2018-6
关键词: n-heptane/isobutanol vapor recompression heat integration low and/or high-pressure options
标题 作者 时间 类型 操作
Determining casting defects in near-net shape casting aluminum parts by computed tomography
Jiehua LI, Bernd OBERDORFER, Daniel HABE, Peter SCHUMACHER
期刊论文
Interfacial heat transfer coefficient between metal and die during high pressure die casting process
GUO Zhipeng, XIONG Shoumei, CHO SangHyun, CHOI JeongKil
期刊论文
Theoretical study of failure in composite pressure vessels subjected to low-velocity impact and internalpressure
Roham RAFIEE, Hossein RASHEDI, Shiva REZAEE
期刊论文
Ionic strength directed self-assembled polyelectrolyte single-bilayer membrane for low-pressure nanofiltration
期刊论文
Using mRNA to investigate the effect of low-pressure ultraviolet disinfection on the viability of
Chao Yang, Wenjun Sun, Xiuwei Ao
期刊论文
Study of the robustness of a low-temperature dual-pressure process for removal of CO
Stefania Moioli, Laura A. Pellegrini, Paolo Vergani, Fabio Brignoli
期刊论文
Catalytic ozonation of reactive red X-3B in aqueous solution under low pressure: decolorization and OH
Hong SUN,Min SUN,Yaobin ZHANG,Xie QUAN
期刊论文
Spray characteristics of high-pressure swirl injector fueled with alcohol
WANG Xibin, CHEN Wansheng, GAO Jian, JIANG Deming, HUANG Zuohua
期刊论文
Hybrid forming mechanism of patternless casting and laser cladding
Zhongde SHAN, Fuzhen SUN, Yang LIU
期刊论文