检索范围:
排序: 展示方式:
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
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
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
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
Chung Nguyen VAN; Hai TRAN THANH; Thuc Nhu NGUYEN; Jianchun LI
《结构与土木工程前沿(英文)》 2022年 第16卷 第11期 页码 1424-1435 doi: 10.1007/s11709-022-0870-9
关键词: ECC fiber orientation distribution casting direction casting position
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
Thermal deflection analysis of the solidified shell in continuous casting of slab
LIU Hongzhao, WANG Zhongmin
《机械工程前沿(英文)》 2007年 第2卷 第2期 页码 175-179 doi: 10.1007/s11465-007-0029-3
关键词: s reciprocal loading deflection expression reciprocal opposite
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
柳百成
《中国工程科学》 2000年 第2卷 第9期 页码 29-37
面向市场经济,迎接全球化竞争的挑战,为国民经济的发展作贡献,就要十分重视制造业特别是铸造行业的发展。但是,我国铸造行业与国外相比有很大差距,它制约着国民经济的发展。世界各国在铸造成形加工技术的发展趋势方面,认识是一致的,即:一是大型工程中特大型铸件的关键铸造技术;二是向精确成形技术方向发展;三是用计算机模拟仿真逐步代替传统的经验性研究方法。铸造过程计算机模拟仿真是改造传统铸造产业的必由之路,是当今世界各国专家学者关注的热点。铸造充型凝固过程的数值模拟可以帮助工程技术.人员优化工艺设计,缩短试制周期、降低生产成本、确保铸件质量,已成为铸造领域最热门的研究课题之一。目前,凝固过程的流场、温度场数值模拟及缩孔缩松预测已应用于实际生产,应力分析、微观组织模拟等方面的基础研究及实用化进程都取得了很大进展。
Digital high-efficiency print forming method and device for multi-material casting molds
Zhongde SHAN, Zhi GUO, Dong DU, Feng LIU, Wenjiang LI
《机械工程前沿(英文)》 2020年 第15卷 第2期 页码 328-337 doi: 10.1007/s11465-019-0574-6
关键词: multi-material casting mold 3D printing efficient print forming method
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
用于制造高效低成本太阳能电池的单晶种铸造大型单晶硅 Article
Bing Gao,Satoshi Nakano,Hirofumi Harada,Yoshiji Miyamura,Takashi Sekiguchi,Koichi Kakimoto
《工程(英文)》 2015年 第1卷 第3期 页码 378-383 doi: 10.15302/J-ENG-2015032
为了能以低成本生产优质大型单晶硅,笔者提出了单晶种铸造技术。这项技术的实施,必须解决两个问题,即坩埚壁上的多晶成核问题和晶体内的位错增殖问题。在本文中,笔者尝试通过数值分析法来解决这两个问题。根据数值分析得出的优化熔炉结构和工况进行了实验,在实验中采用单晶种铸造技术来生长单晶硅。实验结果表明,该技术远优于常用的高性能多晶和准单晶铸造技术。
大块非晶合金:历史发展和当前研究 Review
Akihisa Inoue
《工程(英文)》 2015年 第1卷 第2期 页码 185-191 doi: 10.15302/J-ENG-2015038
通过关注采用传统模型铸造方法合成首批大块非晶合金的触发点,本文论述了大块非晶合金的当前研究进展情况。该综述涵盖大块非晶合金的背景、发现、特点和应用以及近期与其相关的研究主题。由于其性质独特,非晶形成能力高且成本低廉,大块非晶合金 ( 尤其是铁基大块非晶合金) 的应用范围正逐步扩大。在不久的将来,大块非晶合金在工程领域的重要性预计将稳步提高,预期将上述创新型金属材料用于基础科学研究的热度仍将持续。
Efficient MgO-doped CaO sorbent pellets for high temperature CO
Zhihong Xu, Tao Jiang, Hao Zhang, Yujun Zhao, Xinbin Ma, Shengping Wang
《化学科学与工程前沿(英文)》 2021年 第15卷 第3期 页码 698-708 doi: 10.1007/s11705-020-1981-2
关键词: MgO doping CaO sorbent pellets gel-casting technique CO2 capture
标题 作者 时间 类型 操作
Hybrid forming mechanism of patternless casting and laser cladding
Zhongde SHAN, Fuzhen SUN, Yang LIU
期刊论文
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
Numerical investigation of the influence of casting techniques on fiber orientation distribution in ECC
Chung Nguyen VAN; Hai TRAN THANH; Thuc Nhu NGUYEN; Jianchun LI
期刊论文
Thermal deflection analysis of the solidified shell in continuous casting of slab
LIU Hongzhao, WANG Zhongmin
期刊论文
Digital high-efficiency print forming method and device for multi-material casting molds
Zhongde SHAN, Zhi GUO, Dong DU, Feng LIU, Wenjiang LI
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
用于制造高效低成本太阳能电池的单晶种铸造大型单晶硅
Bing Gao,Satoshi Nakano,Hirofumi Harada,Yoshiji Miyamura,Takashi Sekiguchi,Koichi Kakimoto
期刊论文