空中自动同步脱钩吊具设计与分析
作者：
张伟;李明益;周明坡;张有锁;郭龙;...
期刊：
公路与汽运 ,2020年(02):130-132 ISSN：1671-2668
作者机构：
中交天航港湾建设工程有限公司,天津 300450;长沙理工大学 水利工程学院,湖南 长沙 410114;长沙理工大学 汽车与机械工程学院,湖南 长沙 410114;[毛聪; 常留红] 长沙理工大学;[李明益; 郭龙; 张有锁; 周明坡; 张伟] 中交天航港湾建设工程有限公司
关键词：
工程机械;空中脱钩;吊具;自动同步抛投
摘要：
针对重物在空中脱钩难、抛投成本高、准确度低、存在安全隐患等问题,提出并制备一种脱钩吊具,实现重物的空中自动同步脱钩抛投;开展该吊具的有限元受力分析,保证吊具的强度、刚度要求;进行透水框架的抛投试验和空中抛投75万架透水框架的工程应用。结果表明,该吊具的危险位置未出现疲劳裂纹,疲劳强度满足施工要求;可显著减轻工人劳动强度,降低施工安全隐患;能增加每次抛投重物的数量,提高抛投效率。
语种：
中文
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小口径非球面硫系玻璃镜片的非等温热压成型仿真与实验
作者：
唐昆;李典雨;舒勇;朱勇建;王宇;...
期刊：
红外与激光工程 ,2019年48(8):199-210 ISSN：1007-2276
作者机构：
长沙理工大学 机械装备高性能智能制造关键技术湖南省重点实验室, 湖南 长沙 410114长沙理工大学 工程车辆轻量化与可靠性技术湖南省高校重点实验室, 湖南 长沙 410114;浙江科技学院 机械与汽车工程学院, 浙江 杭州 310023;[李典雨] 李典雨;[王宇] 王宇;[毛聪] 毛聪
关键词：
小口径;硫系玻璃;非球面;热压成型;非等温
摘要：
为提高小口径非球面硫系玻璃镜片热压成型质量, 避免成型缺陷, 通过热压过程的有限元分析, 提出了一种新的非等温热压成型法。在上模仁和上加热板之间设置加热间隙, 对上、下加热板设置不同的加热温度, 以实现玻璃预形体的非等温加热。首先, 根据硫系玻璃高温粘弹性本构模型和热传递模型, 结合相关参数建立了镜片热压过程的有限元模型; 接着, 采用所建立的模型, 分析了非等温温差对玻璃预形体内部的温度分布、成型镜片最大残余应力分布及轮廓偏移量的影响, 以确定最佳的温差值; 最后, 进行了镜片的非等温热压成型实验, 并将仿真和实验结果进行了对比研究, 以验证仿真模型和结果的有效性。仿真与实验结果均表明, 最佳的非等温温差值为10 ℃。该条件下, 仿真获得的玻璃预形体内部温度差仅为2.6 ℃, 成型镜片最大残余应力可减至3.375 MPa, 成型镜片ASP1和ASP2的轮廓偏移量最大值分别为0.562 μm和0.615 μm; 实验获得的成型镜片ASP1和ASP2的PV值分别为118.2、194.0 nm, Ra值分别为17.0、37.8 nm, 轮廓偏移量最大值分别为0.583、0.644 μm, 均满足精度要求。仿真与实验结果具有较好的一致性, 采用合理的温差值进行镜片的非等温热压成型, 可有效降低玻璃预形体内部温度差及成型镜片最大残余应力, 避免粘连、气泡等成型缺陷, 提高成型镜片的精度。
语种：
中文
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Experiments on formation mechanism of root humping in high-power laser autogenous welding of thick plates with stainless steels
作者：
Zhang, Mingjun* ;Zhang, Yingzhe;Mao, Cong;Hu, Yongle;Chen, Genyu;...
期刊：
OPTICS AND LASER TECHNOLOGY ,2019年111:11-19 ISSN：0030-3992
通讯作者：
Zhang, Mingjun
作者机构：
[Hu, Yongle; Zhang, Mingjun; Mao, Cong] Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;[Zhang, Yingzhe] Guizhou Inst Technol, Coll Mat & Met Engn, Guiyang 550003, Guizhou, Peoples R China.;[Zhang, Mingjun; Zhang, Yingzhe; Chen, Genyu] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Bi, Zhuming] Purdue Univ Ft Wayne, Dept Civil & Mech Engn, Ft Wayne, IN 46805 USA.
通讯机构：
[Zhang, Mingjun] C;Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.
关键词：
Fiber lasers;High power lasers;High speed cameras;Laser beam welding;Plates (structural components);Steel fibers;Autogenous laser welding;Deep penetration laser welding;Focal positions;High speed imaging;High speed imaging systems;Root hump;Stainless steel plate;Thick plate;Stainless steel
摘要：
Deep penetration laser welding is an efficient and effective way to produce the heavy section structure. Deep penetration can be achieved by high-power autogenous laser welding; however, it poses a significant challenge in obtaining good quality of welds, which are free of imperfects such as root hump, under-fill, and collapse. It is partially attributed to a lacking of understanding on the formation of imperfects. In this paper, we looked into the formation mechanism of root humping experimentally. The laser autogenous welding were implemented using a 10 kW fiber laser on thick stainless steel plates. A high-speed imaging system was applied to observe the metallic vapor and molten pool flow during the welding process. The formation mechanism of root humping with different focal positions were analyzed and discussed. The results showed that the most important welding parameter was the focal position; it had a strong effect on the formation of root hump; it affected the penetration mode of laser keyhole welding. The root hump had a large volume and were generated periodically when a positive defocus was applied. When a negative defocus was applied, the root hump had a small volume and with no obvious periodicity. On the other hand, the welding speed could be optimized to suppress root hump only when a negative defocus was applied. Finally, applying a bottom shielding gases played a positive role in reducing root hump. The results from our study provides the evidences to develop the strategies to suppress root hump during high-power laser autogenous welding on thick metal plates. © 2018 Elsevier Ltd
语种：
英文
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Tribological behavior of cBN-WC-10Co composites for dry reciprocating sliding wear
作者：
Mao, Cong* ;Zhou, Fangjian;Hu, Yongle;Cai, Peihao;Jiang, Yifeng;...
期刊：
Ceramics International ,2019年45(5):6447-6458 ISSN：0272-8842
通讯作者：
Mao, Cong
作者机构：
[Hu, Yongle; Zhou, Fangjian; Mao, Cong; Jiang, Yifeng; Bi, Zhuming; Cai, Peihao] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Hu, Yongle; Zhou, Fangjian; Mao, Cong; Jiang, Yifeng; Bi, Zhuming; Cai, Peihao] Changsha Univ Sci & Technol, Hunan Prov Key Lab Intelligent Mfg Technol High P, Changsha 410114, Hunan, Peoples R China.;[Bi, Zhuming] Purdue Univ Ft Wayne, Dept Civil & Mech Engn, Ft Wayne, IN 46805 USA.;[Peng, Guanqing] Yuhuan CNC Machine Tool Co Ltd, Changsha 410323, Hunan, Peoples R China.
通讯机构：
[Mao, Cong] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
CBN-WC-10Co;Coefficient of friction (CoF);Dry reciprocating sliding;Tribological behavior;Wear resistance
摘要：
This work aims to understand the tribological behavior of cBN-WC-10Co composites subjected to the dry reciprocating sliding wear. The tribological behavior was characterized by the coefficient of friction (CoF) and the specific wear rate. The wear test was designed and performed on the composites against SiC ceramic ball at an ambient temperature, and the SEM morphologies for both of the composites and SiC ceramic ball were measured to reveal their tribological behavior. It was found that the cBN-WC-10Co composites was worn out in two manners, i.e., abrasive wear and oxidation wear, and the abrasive wear was dominant. The cBN particles in the composites were worn out by polishing, fracturing and pulled-out. It was also found that (1) adding cBN particles improved the wear resistance of cBN-WC-10Co composites greatly in comparison with that of the WC-10Co cemented carbides; (2) reducing particle sizes in cBN-WC-10Co composites reduced the specific wear rate when the normal load was below certain value (50 N); while using large particle sizes showed better wear resistance when the normal load was continuously increased. The wear of SiC counter body was much severer when against cBN-WC-10Co composites in comparison with that against WC-10Co cemented carbides. This was due to the fact that the cBN particles in the composites acted as micro cutting edges to wear SiC ceramic. © 2018 Elsevier Ltd and Techna Group S.r.l.
语种：
英文
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Wear mechanism of single cBN-WC-10Co fiber cutter in machining of Ti-6Al-4V alloy
作者：
Mao, Cong* ;Zhang, Yuchen;Peng, Xiaoxiao;Zhang, Bi;Hu, Yongle;...
期刊：
Journal of Materials Processing Technology ,2018年259:45-57 ISSN：0924-0136
通讯作者：
Mao, Cong
作者机构：
[Hu, Yongle; Mao, Cong; Peng, Xiaoxiao; Zhang, Yuchen] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Zhang, Bi] Univ Connecticut, Dept Mech Engn, Storrs, CT 06269 USA.;[Zhang, Bi] Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China.;[Bi, Zhuming] Purdue Univ Ft Wayne, Dept Civil & Mech Engn, Ft Wayne, IN 46805 USA.
通讯机构：
[Mao, Cong] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
Abrasion;Cobalt alloys;Cubic boron nitride;Cutting;Cutting tools;Fibers;Piles;Scanning electron microscopy;Surface roughness;Ternary alloys;Titanium alloys;Tribology;Vanadium alloys;CBN-WC-10Co fiber cutter;Cutting forces;Pile-ups;Scratch test;Ti-6Al-4V alloy;Wear mechanisms;Aluminum alloys
摘要：
In order to explore the wear mechanism of single cBN-WC-10Co fiber cutter in machining of Ti-6Al-4V alloy, this study performs scratch tests, and develops a theoretical model based on the evaluation of cutting performance. The scratch and wear morphologies of the fiber cutter are analyzed by an optical profilometer and scanning electron microscopy (SEM). The wear behavior of the fiber cutter is evaluated comprehensively in terms of cutting forces, the wear morphology of fiber and the profile of scratches with respect to cutting passes. The presented study finds that the wear of the single fiber cutter shows three types, i.e., (1) wear at the cutting edge; (2) abrasion on the local flank face; and (3) abrasion on the new flank face. The identified types of the wear are progressed at three wear stages with different cutting passes. Furthermore, when the number of cutting passes is increased from 1 to 65, the pile-up ratio is increased from 0.11% to 9.95%; while the surface roughness over the scratch is increased from 1.30 μm to 3.73 μm. Accompanying by the increase of cutting passes and the growth of the fiber wear, the cutting force and the normal to tangential force ratio are gradually increased. The machining efficiency and the quality of the machined surfaces are decreased when the local flank face or the new flank face is developed. The mechanical model of the single fiber cutter is established for the machining of Ti-6Al-4V alloy, and a theoretical wear model is developed to give the rationales of the acquired data of wear and cutting forces from experiments. © 2018 Elsevier B.V.
语种：
英文
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项目驱动的机械设计实践课程反向设计与研究
作者：
尹来容;张健;胡宏伟;毛聪;彭翠芳;...
期刊：
机械设计 ,2018年(S2):203-205 ISSN：1001-2354
作者机构：
长沙理工大学汽车与机械工程学院;[何志勇; 毛聪; 尹来容; 彭翠芳; 胡宏伟; 张健] 长沙理工大学
关键词：
机械设计;课程改革;反向设计
摘要：
根据机械设计类本科生实践课程内容与特点,对课程设计、毕业设计进行一体化反向设计,重点培养机械类本科生创新思维与解决工程问题的能力。根据CDIO与专业认证要求的"知识-能力-素质"体系,首先,整合机械原理与机械设计两门课程的课程设计,从课程理论知识体系上训练学生的创新思维与工程实践知识,其次,引入训练创新与工程实践的机械设计大作业,结合课程改革配备的专业指导教师,综合训练学生运用所学机械专业知识进行分析与解决问题的能力,进一步深入培养解决工程实际项目的能力,然后,基于课程大作业,开展机械类本科毕业选题工作。课程大作业选题来源分为学生根据自身兴趣选题、大学生科技立项、研究性学习与创新性实验项目、机械学科竞赛主题、专业指导教师横向/纵向项目等。
语种：
中文
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Analysis of mechanisms of underfill in full penetration laser welding of thick stainless steel with a 10 kW fiber laser
作者：
Zhang, Mingjun* ;Zhang, Zheng;Tang, Kun;Mao, Cong;Hu, Yongle;...
期刊：
OPTICS AND LASER TECHNOLOGY ,2018年98:97-105 ISSN：0030-3992
通讯作者：
Zhang, Mingjun
作者机构：
[Hu, Yongle; Zhang, Mingjun; Mao, Cong; Tang, Kun] Changsha Univ Sci & Technol, Key Lab Lightweight & Reliabil Technol Engn Vehic, Educ Dept Hunan Prov, Changsha 410114, Hunan, Peoples R China.;[Zhang, Zheng] Jishou Univ, Coll Phys Mech & Elect Engn, Jishou 416000, Peoples R China.;[Zhang, Zheng; Zhang, Mingjun; Chen, Genyu] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Zhang, Mingjun] C;Changsha Univ Sci & Technol, Key Lab Lightweight & Reliabil Technol Engn Vehic, Educ Dept Hunan Prov, Changsha 410114, Hunan, Peoples R China.
关键词：
Fiber lasers;Laser beam welding;Liquid metals;Steel fibers;Welding;Welds;Analysis of mechanisms;Experimental investigations;Formation mechanism;High speed imaging;Keyhole;Periodic fluctuations;Thick plate;Underfills;Stainless steel
摘要：
With the aim to explore the formation mechanisms of surface underfill, full penetration laser welding of thick stainless steel was conducted, with the use of a 10 kW fiber laser. A modified “sandwich” specimen was used, so as to directly observe the dynamic behaviors of the keyhole, vapor plume, and melt pool with the formation of underfills. On the basis of the experimental investigations, the formation mechanisms of the underfills at the top surface and bottom surface were analyzed. The results show that the downward flow of the molten metal caused by the recoil momentum is a crucial driver for formation of the underfill on the top surface. At full penetration of the melt, a deep underfill with a periodic wide–narrow–wide serrated pattern is formed on the top surface of the weld owing to the periodic fluctuation of the rear keyhole wall. At full penetration of the keyhole, the formation of a deep underfill on the top surface of the weld and undercut on the bottom surface of the weld is presented with massive direct melt loss from the weld pool. © 2017 Elsevier Ltd
语种：
英文
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Effects of processing parameters on underfill defects in deep penetration laser welding of thick plates
作者：
Zhang, Mingjun* ;Tang, Kun;Zhang, Jian;Mao, Cong;Hu, Yongle;...
期刊：
International Journal of Advanced Manufacturing Technology ,2018年96(1-4):491-501 ISSN：0268-3768
通讯作者：
Zhang, Mingjun
作者机构：
[Hu, Yongle; Zhang, Jian; Zhang, Mingjun; Mao, Cong; Tang, Kun] Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;[Zhang, Mingjun] Changsha Univ Sci & Technol, Sch Energy & Power Engn, Key Lab Efficient & Clean Energy Utilizat, Changsha 410114, Hunan, Peoples R China.;[Zhang, Mingjun; Chen, Genyu] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.
通讯机构：
[Zhang, Mingjun] C;[Zhang, Mingjun] H;Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;Changsha Univ Sci & Technol, Sch Energy & Power Engn, Key Lab Efficient & Clean Energy Utilizat, Changsha 410114, Hunan, Peoples R China.;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.
关键词：
Fiber laser welding;Thick plate;Underfill defects;Processing parameter;Parameter optimization
摘要：
Underfill defect in welding affects not only the surface integrity but also the mechanical properties of workpiece. In this paper, the effects of the process parameters on underfill defects were investigated, and the deep penetration welding by a 10-kW fiber laser on 12-mm-thick stainless steel plates was used as the case study. The correlation of the processing parameters with the formation and elimination of underfill defects was analyzed and discussed. It was found that during the autogenous laser welding of thick plates, the direction of laser beam relative to gravity has a significant effect on the formation of underfill defects, and the preferable direction was an inclination angle of 60° with respect to the gravity. A negative defocus tended to obtain a full penetration weld with underfill and undercut defects. The higher the welding speed was, the lower the underfill depth was on the top surface. This phenomenon was observed on the full penetration welds at a defocus of − 10mm. With a negative defocus, it became feasible to optimize the combination of the focal position and the welding speed to achieve a satisfactory appearance of welds. In addition, a bottom-shielding ambience helped the full penetration in the laser welding process positively. © 2018, Springer-Verlag London Ltd., part of Springer Nature.
语种：
英文
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Simulation and experiment of cutting characteristics for single cBN-WC-10Co fiber
作者：
Mao, Cong* ;Lu, Ji;Zhao, Zhihang;Yin, Lairong;Hu, Yongle;...
期刊：
Precision Engineering-Journal Of The International Societies For Precision Engineering And Nanotechnology ,2018年52:170-182 ISSN：0141-6359
通讯作者：
Mao, Cong
作者机构：
[Hu, Yongle; Mao, Cong; Zhao, Zhihang; Lu, Ji; Yin, Lairong; Bi, Zhuming] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Mao, Cong] Hunan Prov Key Lab High Efficiency & Precis Machi, Xiangtan 411201, Peoples R China.;[Bi, Zhuming] Purdue Univ, Dept Civil & Mech Engn, Ft Wayne, IN 46805 USA.
通讯机构：
[Mao, Cong] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
Single fiber;cBN-WC-10Co;Cutting characteristics;Simulation;Single grain
摘要：
To explore the cutting characteristics of single fiber, the cutting process of Ti-6Al-4 V titanium alloy by single cBN-WC-10Co fiber was simulated, and the fiber size was given as 6 mm in length and 0.8 mm ×0.8 mm in cross-section. The geometry of single fiber was modeled and the material model of Ti-6Al-4 V titanium alloy was established using the Johnson-Cook constitutive equation. The minimal thermal resistance method was combined with the specific effective thermal conductivity method to obtain the thermal conductivity of cBN-WC-10Co composites. To evaluate the grinding performance of single cBN-WC-10Co fiber, both of the comparative experiment and simulation were conducted. The simulation was used to predict the deformation and cutting temperature occurring to the workpiece, as well as the cutting force and the wear depth occurring to the single fiber. The cutting experiments were conducted on Ti-6Al-4 V titanium alloy by both of grinding tools with single fiber and single conical grain for the comparison. It was found that the cutting temperatures of single fiber were 50–100 °C lower, the wear depths were 7%–15% less, and the cutting forces were 1–5 N larger than those of single grain at the same process parameters. The cutting force ratios of single fiber were much less than those of single grain. The results from the comparative experiment were aligned with the simulation results that single fiber was able to develop chips easily, while more plastic deformation occurred on the workpiece cut by single grain. This indicated that the cBN-WC-10Co fiber improved the material removal performance greatly in comparison with the CBN grain.<br/> ©2017 Elsevier Inc.
语种：
英文
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小口径双非球面硫系玻璃镜片精密模压成型实验研究
作者：
唐昆;孔明慧;朱勇建;陈逢军;毛聪;...
期刊：
红外与激光工程 ,2018年47(4):224-232 ISSN：1007-2276
作者机构：
[唐昆; 孔明慧; 毛聪; 张明军] Key Laboratory of Lightweight and Reliability Technology for Engineering Vehicle, Education Department of Hunan Province, Changsha University of Science and Technology, Changsha;410114, China;[朱勇建] School of Mechanical and Automotive Engineering, Zhejiang University of Science and Technology, Hangzhou;310023, China;[陈逢军] College of Mechanical and Vehicle Engineering, Hunan University, Changsha
关键词：
硫系玻璃;小口径双非球面;模压成型;模压温度;加压载荷;保持压力
摘要：
为实现小口径双非球面硫系玻璃镜片的精密模压成型制造, 通过正交模压成型实验, 研究了相关工艺参数对成型镜片质量的影响规律。首先, 介绍了模压成型过程和用于实验的PFLF7-60A型多工位模压成型机床, 并根据非球面曲线公式设计了目标镜片。然后, 选定了一种环保型硫系玻璃IRG205, 通过VFT方程拟合了玻璃粘度与温度之间的关系, 确定了模压温度, 并对各工位实验参数进行了设置。最后, 利用无镀膜模具及球形预形体进行了正交模压成型实验, 分析了实验条件下模压温度、加压载荷及保持压力等成型工艺参数对镜片成型质量(形状精度PV、表面粗糙度Ra及轮廓偏移量)的影响规律, 并获得了优化的成型工艺参数。结果显示: 在优化的工艺参数下, 成型镜片ASP1和ASP2的PV值分别为129.2 nm和174.8 nm, Ra值分别为19.6 nm和25.6 nm, 轮廓偏移量分别为0.614 μm和2.682 μm, 基本满足镜片高精度应用的要求, 为小口径双非球面硫系玻璃镜片的高精度批量制造提供了参考和依据。 In order to realize the precision molding of small dual aspherical chalcogenide glass lenses, the influence of the relevant process parameters on the quality of molded lenses was studied by orthogonal molding experiment. Firstly, the molding process and the PFLF7-60A multi-station molding machine were introduced, the target lens was designed according to the aspheric curve formula. Secondly, an environmentally friendly chalcogenide glass IRG205 was selected, and the relationship between the viscosity and temperature of the glass was fitted by the VFT equation, then the molding temperature was determined, and the experimental parameters of each station were also established. Finally, the orthogonal molding experiments were conducted with no-coated mold and spherical preform, the regular influence of molding process parameters such as molding temperature, pressing load and maintenance force on the lenses′ molding quality(form accuracy PV, surface roughness Ra and profile deviation) were analyzed, and the optimized molding process parameters were obtained. The results have demonstrated that the values of PV for ASP1 and ASP2 are 129.2 nm and 174.8 nm, the values of Ra are 19.6 nm and 25.6 nm, and the values of profile deviation are 0.614 μm and 2.682 μm, respectively. The results can satisfy the requirements for high-precision applications of lenses, and provide reference and basis for the high-precision mass production of small dual aspheric chalcogenide glass lenses.
语种：
中文
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Experimental investigation of phase relations in Al-Co-Y ternary system
作者：
Jiang, Yurong;Li, Xian;Jiang, Yun;Huang, Shuaixiong;Shi, Xi;...
期刊：
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY ,2017年56:1-9 ISSN：0364-5916
通讯作者：
Zhang, Ligang;Liu, Libin
作者机构：
[Shi, Xi; Mao, Cun; Huang, Shuaixiong; Zheng, Feng; Li, Xian; Liu, Libin; Zhang, Ligang; Liu, LB; Jiang, Yurong] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Jiang, Yun] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Peoples R China.
通讯机构：
[Zhang, LG; Liu, LB] C;Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Al-Co-Y;Crystal structure;Isothermal section;Phase diagram
摘要：
Phase relations in the Al-Co-Y ternary system at 1173 K have been established by means of scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD) techniques. Isothermal section at 1173 K of this system was constructed, which consists of 27 three-phase regions and 50 two-phase regions (27wider+23line). The ternary compound τ5-AlCo2Y2 has been confirmed to exist and the crystal structure has been preliminarily analyzed with pattern indexing method as well. The intermetallic phase Co2Y, Co3Y, Co7Y2, Co5Y, Co17Y2, Al2Y, τ4-AlCoY and τ5-AlCo2Y2 were expressed as the formula of AlxCo2−xY, AlxCo3−xY, AlxCo7−xY2, AlxCo5−xY, AlxCo17−xY2, Al2−xCoxY, Al1+xCo1−xY and Al1−xCo2+xY2, respectively. © 2016 Elsevier Ltd
语种：
英文
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地方高校研究生创新能力与学术贡献率提升机制探索
作者：
张健;毛聪;胡宏伟;张志勇;王向红
期刊：
科技创新导报 ,2017年14(21):238-239 ISSN：1674-098X
作者机构：
长沙理工大学汽车与机械工程学院 湖南长沙 410114;[毛聪; 王向红; 张志勇; 胡宏伟; 张健] 长沙理工大学
关键词：
研究生;创新能力;学术贡献率
摘要：
在ESI新背景下,充分发挥地方高校研究生的科研创新能力,有效提升其学术贡献率,将对促进高水平大学及重点学科建设具有重要意义.本文从创新型研究生选拔、导师组组建、课程体系与教学方法改革、学术交流与实践平台搭建、创新能力与学术贡献率评价及激励等方面,对地方高校研究生创新能力与学术贡献率的提升机制进行了初探.
语种：
中文
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CBN-WC-10Co复合材料单纤维切削性能
作者：
毛聪;卢继;梁昶;张明军;胡永乐
期刊：
机械工程学报 ,2017年53(15):188-200 ISSN：0577-6686
通讯作者：
Mao, Cong(maocong315@aliyun.com)
作者机构：
[张明军; 毛聪; 卢继; 胡永乐; 梁昶] College of Automotive and Mechanical Engineering, Changsha University of Science &, Technology, Changsha, 410114, China;[张明军; 毛聪; 卢继; 胡永乐; 梁昶] Key Laboratory of Lightweight and Reliability Technology for Engineering Vehicle, College of Hunan Province, Changsha University of Science &, Technology, Changsha, 410114, China
通讯机构：
College of Automotive and Mechanical Engineering, Changsha University of Science & Technology, Changsha, China
关键词：
单纤维切削;切削性能;划痕形貌;切削力;材料去除率
摘要：
利用放电等离子烧结技术和电火花线切割技术制备了尺寸为6 mm×0.8 mm×0.8 mm的CBN-WC-10Co复合材料纤维,刃磨后纤维前角为0°、后角为20°、刃口锋利平直,能够将这种CBN-WC-10Co纤维替代传统CBN磨粒并进行有序排布制备成有序化纤维刀具。开展了单纤维和单颗CBN磨粒在相同条件下单道切削TC4钛合金的对比试验。结果表明,CBN-WC-10Co单纤维的切削力比(Fn/Ft)、切削比能小,且加工质量可与CBN单颗磨粒相媲美;切削时纤维是以零前角对工件进行切削加工,且纤维的两侧面均与加工表面始终保持相互垂直,工件材料受到纤维的挤压作用而向纤维前端及两侧塑性流动大大减少,切削划痕两侧和切出端的材料堆积现象大为减轻;纤维切削划痕沿着切削方向的材料去除率为98.1%~99.1%,材料堆积率为0.9%~1.9%,而磨粒的材料去除率和材料堆积率分别为-54%~86%和10%~160%,表明纤维的材料去除性能比单颗磨粒的好,因此,可以适当地增大纤维的切削参数来实现材料的高效切削加工。
语种：
中文
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Experimental investigation of Ti-Nb-Co ternary system at 1000 °C
作者：
Huang, Shuaixiong;Zhang, Xingdong;Jiang, Yun;Jiang, Yurong;Mao, Cun;...
期刊：
Materials & Design ,2017年115:170-178 ISSN：0264-1275
通讯作者：
Zhang, Ligang;Liu, Libin
作者机构：
[Zhang, Xingdong; Mao, Cun; Huang, Shuaixiong; Liu, Libin; Zhang, Ligang; Liu, LB; Jiang, Yurong; Wu, Di] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Jiang, Yun] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Zhang, LG; Liu, LB] C;Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Bins;Isotherms;Phase diagrams;Phase equilibria;Solubility;Ternary systems;X ray diffraction;X ray spectrometers;Co systems;Diffusion couple;Electron probe microscopy;Experimental investigations;Isothermal sections;Three-phase equilibria;Two-phase equilibria;Wave dispersive x-rays;Titanium alloys
摘要：
The phase relations in the Ti-Nb-Co system are of great importance for the design of high temperature Ti alloys. The isothermal section of Ti-Nb-Co system at 1000 °C has been established using one diffusion couple supplemented with 13 key alloys. Phase relations and ternary solubility of the binary compounds were determined using electron probe microscopy (EPMA), wave dispersive X-ray spectrometer (WDS) and X-ray diffraction (XRD) techniques. There are 19 two-phase equilibria and 9 three-phase equilibria in the isothermal section at 1000 °C. The determined maximum solubility of Nb in TiCo3, TiCo2 (h), TiCo2 (c), TiCo, Ti2Co were 6.22, 17.21, 2.29, 22.88 and 2.49 at.%, respectively. Nb2Co7, NbCo3, NbCo2, Nb6Co7 dissolves up about 0.33, 17.75, 13.26 and 10.81 at.% Ti, respectively. All of the binary phases have a certain composition range at 1000 °C except Nb2Co7. The phase diagram of Ti-Nb-Co system varied greatly when the temperature raised from 900 °C to 950 °C, but the changes was not so big when temperature increased from 950 °C to 1000 °C. © 2016 Elsevier Ltd
语种：
英文
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面向工程教育专业认证的机械制图课程改革初探
作者：
张明军;唐昆;魏吉双;王向红;张健;...
期刊：
考试周刊 ,2017年(53):39 ISSN：1673-8918
作者机构：
长沙理工大学汽车与机械工程学院 湖南 长沙 410114;[毛聪; 王向红; 魏吉双; 唐昆; 张健; 张明军] 长沙理工大学
关键词：
工程教育专业认证;机械制图;课程改革
摘要：
依照机械类工程教育专业认证标准,结合长沙理工大学机械与汽车工程学院机制专业特色,对照工程教育专业认证中的毕业生素质要求,对机械制图课程的教学目标——毕业要求矩阵关系、教学内容和教学方法改革进行了实践探索,践行以教师为主导,学生为主体的教学模式,提高机械制图课程的教学效果。
语种：
中文
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Grinding characteristics of cBN-WC-10Co composites
作者：
Mao, Cong* ;Liang, Chang;Zhang, Yuchen;Zhang, Mingjun;Hu, Yongle;...
期刊：
Ceramics International ,2017年43(18):16539-16547 ISSN：0272-8842
通讯作者：
Mao, Cong
作者机构：
[Hu, Yongle; Zhang, Mingjun; Mao, Cong; Liang, Chang; Bi, Zhuming; Zhang, Yuchen] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Mao, Cong] Minist Educ, Engn Res Ctr Complex Tracks Proc Technol & Equipm, Xiangtan 411105, Peoples R China.;[Bi, Zhuming] Purdue Univ, Dept Civil & Mech Engn, Ft Wayne, IN 46805 USA.
通讯机构：
[Mao, Cong] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
Grinding;Grinding force;Material removal mechanism;Surface integrity;cBN-WC-10Co
摘要：
In order to explore the grinding characteristics of cBN-WC-10Co composites, the grinding experiment with a resin bond diamond grinding wheel was carried out. The grinding forces, surface roughness, surface morphology and residual stress were investigated. It was found that the material removal mechanism of cBN-WC-10Co was the combination of the brittle fracture of cBN particles, ductile removal of Co phase, plastic deformation, grain dislodgement and grain crush of WC grains. The brittle removal model resulted in a lower specific grinding energy. The main contributor to the surface roughness was cBN particles. Some cBN particles over the surface of cBN-WC-10Co composites were fractured or pulled out and then formed cavities with different depths, this led to a rougher surface. The surface roughness was increased but the specific grinding energy decreased with an increase of the maximum undeformed chip thickness. A high-level residual compressive stress was induced at WC phase and it was increased with an increase of the depth of cut. The depth of cut has more significant influence on the grinding forces than the table speed or the wheel speed.
语种：
英文
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Analysis of flow field in cutting zone for spiral orderly distributed fiber tool
作者：
Zhang, Mingjun;Tan, Yang;Zhou, Fangjian;Mao, Cong* ;Xie, Zhizhou;...
期刊：
International Journal of Advanced Manufacturing Technology ,2017年92(9-12):4345-4354 ISSN：0268-3768
通讯作者：
Mao, Cong
作者机构：
[Tan, Yang; Zhang, Mingjun; Zhou, Fangjian; Mao, Cong; Xie, Zhizhou] Changsha Univ Sci & Technol, Hunan Prov Key Lab Safety Design & Reliabil Techn, Changsha 410114, Hunan, Peoples R China.;[Tan, Yang; Zhang, Mingjun; Zhou, Fangjian; Mao, Cong; Xie, Zhizhou] Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;[Li, Changhe] Qingdao Univ Technol, Sch Mech Engn, Qingdao 266033, Peoples R China.
通讯机构：
[Mao, Cong] C;Changsha Univ Sci & Technol, Hunan Prov Key Lab Safety Design & Reliabil Techn, Changsha 410114, Hunan, Peoples R China.;Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.
关键词：
Spiral orderly distributed fiber tool;Numerical simulation;Useful flow;Cutting fluid
摘要：
In order to reduce the grinding temperature and improve the lubrication and cooling performance of grinding process, a spiral orderly distributed fiber tool was proposed. The simulation of flow field in cutting zone for spiral orderly distributed fiber tool and the grinding experiment were carried out. The results indicate that the useful flow of cutting fluid for the spiral orderly distributed fiber tool is increased obviously, in comparison to the traditional grinding wheel with disordered arrangement of grains. When the fiber number per unit area for the fiber tool is kept constant, the useful flow of cutting fluid is increased with increment of the fiber pitch. When the fluid jet speed or the exit height of the spray nozzle is increased, on the one hand, the useful flow of cutting fluid is increased; but on the other hand, the utilization rate of the useful flow of cutting fluid is reduced. The useful flow of cutting fluid supplying with an angle of 15° on the horizontal direction is significantly higher than that in the horizontal direction. The computational model is validated by cutting experiments with a corundum grinding wheel.
语种：
英文
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Study on the burning loss of magnesium in fiber laser welding of an Al-Mg alloy by optical emission spectroscopy
作者：
Zhou, Li;Zhang, Mingjun* ;Jin, Xiangzhong;Zhang, Honggui;Mao, Cong
期刊：
International Journal of Advanced Manufacturing Technology ,2017年88(5-8):1373-1381 ISSN：0268-3768
通讯作者：
Zhang, Mingjun
作者机构：
[Zhou, Li] Guangdong Polytech Normal Univ, Coll Electromech Engn, Guangzhou 510635, Guangdong, Peoples R China.;[Zhang, Mingjun; Mao, Cong] Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;[Zhang, Mingjun; Zhang, Honggui; Jin, Xiangzhong] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Zhang, Mingjun] C;[Zhang, Mingjun] H;Changsha Univ Sci & Technol, Educ Dept Hunan Prov, Key Lab Lightweight & Reliabil Technol Engn Vehic, Changsha 410114, Hunan, Peoples R China.;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
关键词：
Fiber laser welding;Magnesium loss;Al-Mg alloy;Keyhole plasma;Optical spectroscopy
摘要：
In order to study the burning loss of magnesium, a specially designed device was used to capture the spectrum emitted from the keyhole plasma in deep penetration laser welding of aluminum alloy 5052. The content of magnesium in the weld bead was measured by an electron probe micro-analyzer (EPMA). The effect of the welding parameters on the spectral intensity of magnesium plasma was examined, and the distributions of the spectral intensity of magnesium plasma in the radial and depth directions of the keyhole were investigated. Finally, the mechanism of the magnesium loss was analyzed. The results indicate that burning loss of magnesium can be monitored by spectral analysis technique. The welding parameters have a great effect on the burning loss of magnesium. The influence of welding speed on the burning loss of magnesium on the top surface is dependent on the penetration regime. The distribution of magnesium in the weld is not uniform. In the radial direction of the weld bead, the content of magnesium increases from the center to the edge of the keyhole. In the depth direction of the weld bead, the content of magnesium decreases firstly and then increases from the top to bottom. The maximum burning loss of magnesium occurs at the middle of the weld bead.
语种：
英文
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工程教育专业认证背景下的现代制造技术课程改革初探
作者：
张明军;唐昆;李河清;王向红;张健;...
期刊：
科教文汇(下旬刊) ,2017年(26):44-45 ISSN：1672-7894
作者机构：
长沙理工大学汽车与机械工程学院 湖南·长沙 410114;[毛聪; 王向红; 唐昆; 张健; 李河清; 张明军] 长沙理工大学
关键词：
工程教育专业认证;现代制造技术;课程改革
摘要：
本文依照机械类工程教育专业认证标准, 结合长沙理工大学机械与汽车工程学院机制专业特色,对照工程教育专业认证中的毕业生素质要求,对现代制造技术课程的教学目标-毕业要求矩阵关系、教学内容和教学方法改革进行了实践探索, 践行以教师为主导、学生为主体的教学模式, 以期提高现代制造技术课程的教学效果.
语种：
中文
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Improvement of useful flow rate of grinding fluid with simulation schemes
作者：
Zhang, Yanbin;Li, Changhe* ;Zhang, Qiang;Jia, Dongzhou;Wang, Sheng;...
期刊：
International Journal of Advanced Manufacturing Technology ,2016年84(9-12):2113-2126 ISSN：0268-3768
通讯作者：
Li, Changhe
作者机构：
[Li, Changhe; Jia, Dongzhou; Zhang, Qiang; Zhang, Dongkun; Zhang, Yanbin; Wang, Sheng] Qingdao Univ Technol, Sch Mech Engn, Qingdao 266033, Peoples R China.;[Mao, Cong] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Li, Changhe] Q;Qingdao Univ Technol, Sch Mech Engn, Qingdao 266033, Peoples R China.
关键词：
Scraper;Airbond layer;Grinding fluid;Useful flow rate;Useful flow;Fluid supply
摘要：
In previous studies, the improvement of the useful flow and flow rate of grinding fluid has been investigated via modeling, simulation, and experiment. Optimized grinding parameters have been achieved. A detailed assessment of the improvement in the useful flow rate of grinding fluid, which optimizes the grinding fluid supply, has been published in the International Journal of Advanced Manufacturing Technology (Li et al. Int J Adv Manuf Technol 75:1587-1604, 2014). Then, a detailed experimental study on the improvement in the useful flow rate of grinding fluid has been published in the International Journal of Advanced Manufacturing Technology (Li et al. Int J Adv Manuf Technol 1-10. 2015), in which the influence of grinding wheel speed, grinding fluid jet velocity, particle size, and bulk porosity on useful flow and useful flow rate was analyzed. In this paper, a new method of air scraper is presented and simulated with focus on the air boundary layer and reflux around the grinding wheel. In view of the influence of the gas barrier of grinding wheels on the effective supply of grinding fluid, the effect of the scraper on the gas barrier layer was analyzed through the grinding flow field simulation under unified grinding parameters. Using the air scraper to destroy the gas barrier layer is proposed, and a supply scheme is designed to improve the useful flow rate. Results show that using the scraper has a certain effect on the weakening of the grinding gas barrier layer. In the grinding process, using the scraper can reduce the obstacles to grinding fluid supply, thereby improving the useful flow of grinding fluid into grinding wheel workpieces. The distance between the front end of the plane scraper and the grinding wheel is 10 mu m, with a large circular boot-shaped nozzle. Alternatively, the distance between the front end of the nozzle and the grinding wheel surface is 50 mu m, which can increase the useful rate of flow of grinding fluid.
语种：
英文
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