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Zhang X.,Yanshan University | Zhu H.,University of Wollongong | Huang W.,Yanshan University | Shi B.,CITIC Dicastal Wheel Manufacturing Co. | Tieu A.K.,University of Wollongong
International Journal of Materials and Product Technology | Year: 2013

A new method of setting continuous bending and straightening strain rate according to temperature subzone was brought forward. By making use of the high temperature creep character effectively during the continuous casting slab being straightened, a new model curve of continuous caster was developed. And by using theoretical and finite element method the strain and strain rate of the slab under multi-point straightening and the new continuous straightening were analysed. The result shows that for continuous straightening the strain rate of the slab is constant and lower than that of the slab under multi-point straightening, and the strain varies linearly. It is verified that the new continuous straightening technology is reasonable and superior. Copyright © 2013 Inderscience Enterprises Ltd.

Zhao W.M.,Hebei University of Technology | Zhang L.,Hebei University of Technology | Wang Z.F.,Hebei University of Technology | Yan H.J.,Citic Dicastal Wheel Manufacturing Company Ltd
Advanced Materials Research | Year: 2011

This paper studied the effects of inclusion and slag on properties of a die cast A356 alloy wheel. The result showed that the rate of defect is important for the mechanical properties. The tensile strength and extension was not dropped but the rate of defect is increased about 2%. The variation trend of tensile strength and extension is linear, while the area of porosity on tensile fracture is between 2% and 6%. However, the tensile strength and extension was dropped with the increasing rate of defect. The variation trend of mechanical properties of the sample with inclusion is stable, but the sample with slag is not stable. The mechanical properties of samples with inclusion are drastically changed, while the rate of defect is increased. The mechanical properties of samples with slag are smoothly. The EDS analysis indicated that the defects consist of Al-Ti-B compound, α-phase (Al12FeSi), β-phase (Al9Fe2Si2) and Al2O3. These oxides form the compact composite oxide film expand into first cracks. The fracture mode of sample with defects is brittle fracture. The values of the Secondary dendrite arm spacing (DAS) in the inclusion and the matrix are the same, while the values of DAS in the slag and the matrix are different. © (2011) Trans Tech Publications.

Zhao W.M.,Hebei University of Technology | Jia X.F.,Hebei University of Technology | Wang Z.F.,Hebei University of Technology | Yin Z.G.,Citic Dicastal Wheel Manufacturing Company Ltd | Xiong G.Y.,Citic Dicastal Wheel Manufacturing Company Ltd
Advanced Materials Research | Year: 2011

The tube-shaped parts of A356 alloy were deformed from 0% to 83% by spinning process. The microstructure and mechanical properties of A356 alloy were discussed. The results showed that as the wall thickness reduction increases, the dendrite cells of cast alloy are lengthened gradually and the average Secondary Dendrite Arm Spacing (SDAS) is reduced from 37.2μm to 23μm and eutectic silicon particles are distributed orderly along the spinning direction. The coarse acicular β-Al5FeSi is broken into many sections, and its length is reduced from 37.5μm to 12.5μm in the cross-section. The tensile strength and elongation exhibit a strong dependence upon the variation in wall thickness, with a parabolic relationship. The tensile fractured surface of parts with deformation ratio above 35% exhibits many equiaxial dimples, with intergranular ductile fracture mode. © (2011) Trans Tech Publications.

Guan Y.-P.,Yanshan University | Guan Y.-P.,Beijing University of Technology | Guan Y.-P.,CITIC Dicastal Wheel Manufacturing Co. | Wang Z.-H.,Yanshan University | And 3 more authors.
Journal of Harbin Institute of Technology (New Series) | Year: 2013

A high-Ti 6061 alloy was rolled with strains up to 0.8-2.0 and at 350-550°C. Microstructures that developed during deformation and subsequent solution heat treatment (SHT) were observed by using optical and transmission electron microscopy. Microstructure evolution during SHT depends mainly on the initial rolling temperature, and it was found that the higher this temperature is, the coarser the grains are. After rolling at 400°C, well-defined cells and subgrains were formed, which induced further sites for recrystallization nucleation during subsequent SHT. The recrystallization mechanism was found to be subgrain rotation, with a final grain size smaller than 200 μm. Increasing the rolling temperature to 500°C results in a low density of dislocations distributed uniformly in the deformed matrix and fewer nucleation sites during subsequent SHT. The recrystallization mechanism is grain boundary bulging, while the final grain size approaches several millimeters. Finally, a hot forming process of high-Ti 6061 alloy for inhibiting grain coarsening was proposed, and verified by experiments.

Rong Y.,Hebei Normal University of Science and Technology | Rong Y.,CiTiC Dicastal Wheel Manufacturing Co. | Liu S.,CiTiC Dicastal Wheel Manufacturing Co. | Han Y.,CiTiC Dicastal Wheel Manufacturing Co. | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016

In the process of large passenger aircraft manufacturing and assembly, a lot of drilling and milling work needs to be done. Due to the limitation of the structure, the traditional drilling and milling machines can't be used in the drilling and milling work of large passenger aircraft. The hexapod robot with motorized spindle on its trunk is very suitable for the drilling and milling work. The hexapod robot can crawl on the aircraft's exterior surface through suckers on its foot. So the hexapod robot can do the drilling and milling work by the motorized spindle on its trunk. For the hexapod drilling robot, a new type of 3-DOF (3 degrees of freedom) mechanical leg based on (U+UPS)P+UPS parallel mechanism is presented (U, P and S represent universal pair, prismatic pair and spherical joint, respectively). The decoupling performance of the mechanical leg's motions is very good, and its 2 rotational motions are completely decoupled. Its control algorithm is very simple, so it can be real-time controlled very easily. In order to improve the accuracy of the hexapod drilling robot, the error modeling and evaluation method of the mechanical leg is established. The prototype is manufactured by precision design, and the error calibration experiment is done. First, using the vector chain method, the error vector constraint equation is established and the error propagation model is obtained. Using the error model, the mechanical leg's output errors with a given set of error sources can be calculated. Also, the mechanical leg's tolerance allocation with a given set of output errors can be calculated too. In order to evaluate the error transfer performance of the mechanical leg, a set of error sensitivity evaluation indices are defined, and the distribution of error sensitivity evaluation indices in the mechanical leg's workspace is drawn. It reveals that the error transfer characteristics of the mechanical leg are good in the central area of the workspace. Based on the set of indices, the error sensitivity of the mechanical leg is evaluated. Based on the comprehensive consideration of various performance indices of the mechanical leg, the structure parameters are designed by Monte Carlo method. The parameters are as follows: the distance between the universal joints which are connected to the fixed platform is 200 mm, the length of the middle connecting rod is 70 mm, the length of the end connecting rod is 50 mm, and the distance between the middle connecting rod and the main branch's universal joint is 450 mm. Based on this set of structural parameters, the mechanical leg's prototype is manufactured. Finally, using high precision robot calibration system, the error calibration experiment of mechanical leg is done, and the error characteristics of the mechanical leg's prototype are obtained. Experimental results indicate that the deviations between the measured and the theoretical position error are less than 0.003 mm, the deviations between the measured and the theoretical attitude error are less than 0.05°, and the deviations between the measured and the theoretical error sensitivity evaluation index are less than 0.05. So, the error of mechanical leg's prototype is in reasonable range, and the structure and parameters of the mechanical leg have been proved to be reasonable. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.

Yu N.,Citic Dicastal Wheel Manufacturing Co. | Zhu L.,Citic Dicastal Wheel Manufacturing Co. | Dong X.,Shenyang Ligong University
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2016

Based on the heat transfer theory, by simplifying the complicated and unstable question, the condition used to get metal castings without shrinkage porosity in the optimum state was presented. The optimum temperature gradient at the directional solidification direction and the solidification direction from side to center is in direct proportion to the difference between pouring temperature and solidus temperature, and is inversely proportional to the flow distance of liquid alloy at the solidification direction, meanwhile, temperature gradient at three direction should be kept pace. The way of getting the optimum is to make the thickness of coat at the mold cavity become thicker and thicker along the solidification direction, meanwhile, the gradient of coat thickness at the mold cavity should be less in order to produce castings without shrinkage defect efficiently under the optimum temperature gradient with decreasing in the thickness of mold. In addition, the heat conductive coefficient of coat is decreased, while the heat conductive coefficient of mold is increased as a result forced cooling at the beginning stage when the mold-wall of the permanent mold is decreased. © 2016, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.

Zhu Z.,Yanshan University | Sun H.,Yanshan University | Hu J.,Yanshan University | Wang Y.,Yanshan University | Xiao Z.,Citic Dicastal Wheel Manufacturing Co.
2010 International Conference on Mechanic Automation and Control Engineering, MACE2010 | Year: 2010

The simulation was carried out on the forging process of 6061 Aluminum Alloy wheels in this paper. The feasibility was demonstrated. The location and shape of the defection were predicted accurately. The forging simulation has many benefits, such as providing a guidance for the mould design and the process setting, improving the quality of the product, shortening the testing period of the product, increasing general product efficiency, saving the testing cost, decreasing the frequencies of mould reparing and creating significant economic profits etc. The necessary condition was provided by the forging of the aluminum alloy wheels to realize high strengh and lightweight of wheels. ©2010 IEEE.

Yang S.-F.,Yanshan University | Zhao C.-C.,Yanshan University | Jia X.-D.,Yanshan University | Sun C.,CITIC Dicastal Wheel Manufacturing Co. | Dong G.-J.,Yanshan University
Suxing Gongcheng Xuebao/Journal of Plasticity Engineering | Year: 2012

Shaft part local forming is a material-saving and efficient precision plastic forming process.At present, upsetting process is used widely with regard to local forming of the slender rod-shaped blank.For forging deformation ratio of length to diameter ω>2.5, the fittings are prone to fold by one upsetting process step, and need multiple top-upsetting process steps to complete the workpiece.Based on this, this paper first proposed a new technology called local forming process of floating die combining free upsetting, extrusion and closed die forging, which could avoid part bending fold and reduce tensile stress on forming surface.The local forming process of floating die achieved the slender rod-shaped deformation ratio length ω>4 with one-heating forming.Thus a series of issues in the existing process could be solved and also a new way for the local precision forming of the slender rod-shaped blank was derived.

Yuan X.,Yanshan University | Zhang L.,Yanshan University | Chen X.,Yanshan University | Du B.,Yanshan University | And 3 more authors.
Applied Mechanics and Materials | Year: 2012

In order to predict the result of impact test in the design phase and reduce the experimental times, which can save cost and shorten development cycle, a finite element model of aluminum alloy wheel 13-degree impact test is established based on Abaqus. All mechanical parts such as the standard impact block, the assembly of the wheel and the tire, the support and bolts are included in the finite element model. The predicted result of finite element analysis and the experimental result agree very well shows the finite element model is correct. The equivalent plastic strain value was also put forward as fracture criterion for the wheel in the impact test which realizes the transition from the qualitative analysis to the quantitative analysis in the development process of aluminum alloy wheel. © (2012) Trans Tech Publications, Switzerland.

Citic Dicastal Wheel Manufacturing Co. and Citic Dicastal Wheel; Manufacturing Co. | Date: 2013-02-05

Aluminum alloy wheel hubs; tyres for vehicle wheels.

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