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Key engineering materials
Trans Tech Publications Ltd.
Key engineering materials

Trans Tech Publications Ltd.

半月刊

1013-9826

Key engineering materials/Journal Key engineering materials
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    Effects of Surface Strength and Temperature on Warm Forming of MG-AL-SUS Clad Sheet

    Youngseon LeeTaekwoo JungDaeyong KimYounghoon Moon...
    P.183-188页
    查看更多>>摘要：Clad metal sheets are composed of one or more different materials joined by resistance seam welding, roll-bonding process, etc. Good formability is an essential property in order to deform a clad metal sheet to a part or component. Temperature is one of the major factors affected the interface strength and formability on warm forming of multilayered sheet metal. In this study, the mechanical properties and formability of a Mg-Al-SUS clad sheet are investigated. The clad sheet was deformed at elevated temperatures because of its poor formability at room temperature. Tensile tests were performed at various temperatures above 250℃ and at various strain rates. The limit drawing ratio (LDR) was obtained using a deep drawing test to measure the formability of the clad sheet. Interface strength and fracture pattern were changed mainly by temperature. Uniaxial tensile strength represents entirely different type below and above 200℃ at also different strain rate. Mg alloy sheet was fractured earlier more than SUS and Al alloy sheet below 250℃ testing temperature. On the contrary, Mg alloy sheet was elongated much more than other metals above 250℃.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Influence of Annealing Treatment on Formability and Springback for Magnesium Alloy Sheets

    Daeyong KimBum Kyu HwangYoung Seon LeeSang-Woo Kim...
    P.189-194页
    查看更多>>摘要：The purpose of this work is to experimentally investigate the effect of annealing treatment on the formability and springback at room temperature for magnesium alloy AZ31 sheets, which were produced by rolling through reversible warm mill after twin roll strip casting. Microstructure evolutions were investigated using OM after annealing at temperature raging from 350℃ to 450℃. Tensile tests at room temperature were performed to show the influence of annealing treatment on mechanical properties. In order to evaluate the formability in stamping processes, the Erichsen cupping tests were carried out and the Erichsen number were measured. As for springback, the V shaped air bending tests were achieved and the angle changes after springback were collected. The experimental results showed that Erichsen numbers increased by the annealing treatment, while springback angle decreased.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Prediction of Load Capacity Behavior of Multi-Stage Formed Construction Elements

    Ales PetekKarl KuzmanFranc ResmanBoris Jerman...
    P.195-200页
    查看更多>>摘要：The technologies for low-quantity production of sheet metal components and parts are applied mostly for thin single metal sheets. However, such technologies could also be applied as an additional procedure in multi-layer construction element production. Such individually produced construction elements must correspond to required standards, which are usually applied in serial production. Due to the immense testing work expected by custom-made production, it is reasonable to develop a methodology that would be capable of predicting the required results of an individually designed and produced construction block quickly, effectively and with minimal costs. In this investigation, a method of predicting the load capacity behavior of individual construction elements performed by incremental forming as an additional technology in multi-layer construction element production is presented. Special attention is dedicated to the definition of finite element model of a standardized four-point bending test and its correlation to real experimental results.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Reciprocating Shaving Approach to Eliminate Crack and Burr Formations in Pressed Parts

    Sutasn ThipprakmasWiriyakorn PhanitwongMutjarin ChinwitheeThanaporn Morkprom...
    P.201-206页
    查看更多>>摘要：Burrs are unwanted materials remaining not only after the machining operation but also after the sheet metal cutting operation. Burr formations decrease the part accuracy and increase the cost for the deburring operation. In this study, the reciprocating shaving process was proposed to eliminate crack and burr formations in the pressed parts. The finite element method (FEM) was used as a tool to investigate the possibility of this process and its working process parameters as well. The FEM simulation results showed the effects of clearance in shearing operation, shaving allowance, and half-shaving direction on the shaved surface. These results were validated by laboratory experiments, and they showed a good agreement with each other. The FEM simulation could be used as a tool for prediction of the cut surface in the reciprocating shaving process. The results revealed that the reciprocating shaving process could be applied for eliminating crack and burr formations in pressed parts using suitable working process parameters.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Collaborative Aluminum Profile Design to Adaptable Die Process Planning Using Neural Networks

    Suthep ButdeeChaiwat NoomtongSerge Tichkiewitch
    P.207-212页
    查看更多>>摘要：Aluminum extrusion die manufacturing is a critical task for productive improvement and increasing potential of competition in aluminum extrusion industry. It causes to meet the efficiency not only consistent quality but also time and production cost reduction. Die manufacturing consists first of die design and process planning in order to make a die for extruding the customer's requirement products. The efficiency of die design and process planning are based on the knowledge and experience of die design and die manufacturer experts. This knowledge has been formulated into a computer system called the knowledge-based system. It can be reused to support a new die design and process planning. Such knowledge can be extracted directly from die geometry which is composed of die features. These features are stored in die feature library to be prepared for producing a new die manufacturing. Die geometry is defined according to the characteristics of the profile, is called product data, so we can reuse die features from the previous similar profile design cases. This paper presents the artificial neural network to assist aluminum extrusion die design and process planning based on collaborative design methodology. Product data can be shared and distributed in die design team members via computer network technology. This product data is used to support die design and process planning. Die manufacturing cases in the case library would be retrieved with searching and learning method by neural network for reusing or revising it to build a die design and process planning when a new case is similar with the previous die manufacturing cases. The results of the system are dies design and machining process.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Fabrication of a Large-Area Silicon Mold with Microstructures Using a Novel Recombining Technique

    Chih-Wei WuChih-Heng ChiHung-Yin TsaiYung-Kang Shen...
    P.213-218页
    查看更多>>摘要：This paper presents an innovative fabrication of a large-area silicon mold with microstructures. Conventional techniques capable of manufacturing a large size mold pose severe challenges in making microstructures. In contrast, semiconductor process is limited in its wafer scale. This paper shows a new approach to achieve a large beyond-wafer-size silicon mold with alignment microstructures using two-direction passive alignment recombining techniques. Anisotropic bulk-micromachining technique, laterally joined of (111) silicon crystal planes, passive-alignment methods are the key to fabricate a large-area silicon mold. The area of each small silicon plate is 2.9cm~2. Therefore, four small silicon plates with microstructures were recombined as a large-area square silicon mold. The optical fibers were placed into V-grooves on small silicon plates to make sure of microstructures alignment, minimum tilting and rotation angles between plates during the recombining process. The gap, height difference, and aligning accuracy of microstructures between joined silicon plates were able to achieve 8μm, 0.902μm and 20μm, respectively. Moreover, the rotation and tilting angles could be lowered to 0.0622 degree and 0.002 degree, respectively. Microstructures on the large-area silicon mold are faithfully reproduced by polydimethylsiloxane (PDMS). Finally, a 16.8 cm × 12.6 cm silicon mold was fabricated using twelve 4.2cm × 4.2cm silicon plates. It is believed that the novel technique will give an impact and create a highly value-added technology to the precise mold manufacturing.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Die Design in Fine-Piercing Process by Chamfering Cutting Edge

    Suthep YiemchaiyaphumJin MasahikoSutasn Thipprakmas
    P.219-224页
    查看更多>>摘要：The hole quality on sheet metal parts is directly dependent on the die design and process parameters. In conventional piercing process, the secondary operations such as shaving, reaming and grinding are needed for manufacturing the precise-dimensioned holed parts without any cracks, resulting in the increase of both production time and costs. The fine-piercing process, referenced to the fine-blanking principle, is used to produce the precise-dimensioned holed parts with smooth-cut surfaces over the whole material thickness in a single operation. However, it is difficult to achieve the suitable die design and process parameters for meeting the part requirements. In this study, the die design by chamfering punch cutting edge was investigated on both the experiments and the finite-element method (FEM). The results were compared with the results obtained when the conventional die design with the punch cutting-edge radius was used. The FEM-simulation results showed the amount of die-roll, smooth-cut surface, and cracks agreed well with the experimental results. The results showed that an application of punch cutting-edge chamfer results in a superior fine-pierced hole surface could be achieved. Furthermore, the mechanism and effects of the punch cutting-edge chamfer have been theoretically clarified on basis of the material-flow analysis and stress distribution.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Optimisation of the Machining of Stellite 6 PTA Hardfacing Using Surface Roughness

    Md Shahanur HasanAbdul Md MazidRichard E. Clegg
    P.227-231页
    查看更多>>摘要：Stellites are cobalt based super alloys. By virtue of their excellent physio-mechanical properties, stellites are highly regarded engineering materials. Stellites posses high corrosion resistance and wear resistance properties. This study investigates the Stellite deposition process and machinability of Stellite 6 deposited on steel subtrate. Stellite 6 was deposited onto a 4140 bar using a plasma transfer arc (PTA) system and machinability was assessed on the basis of surface roughness. A series of turning operations have been carried out on a conventional lathe using coated carbide inserts and surface roughness was evaluated by Stylus type Surtronic3+ instrument. The values of surface roughness were plotted against different cutting speed, feed rate and depth of cut to display the results in graphical forms. Optimal cutting regimes were established against the best values of surface roughness.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Surfaces Machined by Micro End-Mills at Constant Chip Load

    Jong-Leng LiowUlrich Frye
    P.232-237页
    查看更多>>摘要：The surfaces of A16061, machined by 150 μm two flute micro end-mills, were studied to determine their roughness. The surface roughness, R_a, was less than 100 nm but the R_a/R_z ratio ranged from 0.03-0.12. The surface roughness was found to improve with increasing width of cut and to a lesser extent with increasing feed rate. A single pass of the end-mill was found to produce a smoother surface than two passes over the same surface. The surface roughness was found to correspond to the diameter of the end mill and the slope of the secondary cutting edge. To reduce the surface roughness, smaller diameter end mills and chip loads should be used.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Design Optimization of Cutting Parameters in Turning 45Cr Steel Using Cermets Tool

    Zhilin HanBin LinBaoxing ZhangLei Zhang...
    P.238-243页
    查看更多>>摘要：In this paper, the optimization of cutting parameters in turning thin-walled 45Cr steel workpieces with cermets tool is researched. A new integrated optimization method is proposed, in which the parameter design of the Taguchi method, principal component analysis method and response surface method (RSM) are applied to obtain the optimal parameter for a hard turning process using mixed cermets tools. The orthogonal array experiment is conducted to economically obtain the response measurements. The Principal Component Analysis (PCA) is applied to transform the original evaluation variables into new, uncorrelated comprehensive variables, which includes most information of original variables, then the output response can be calculated by the principal components. At last, the RSM is used to build the relationship between the input parameters and output responses, and obtain the desired machining parameters. The quality of workpieces and the process efficiency are improved obviously.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd