Advances in Materials Manufacturing Science and Technology

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Authors: Zhan Qiang Liu, Yi Wan, Xing Ai
Abstract: High-Speed Machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantly higher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received an important attention as a technological solution for high productivity to increase economic efficiency in manufacturing. The recent developments in cutting tool materials for high speed machining are reviewed in this paper. The appropriate applications of the high speed machining technology are presented. The research is great beneficial to the design and the optimal selection of tool materials for high speed machining.
438
Authors: Zhi Yu Xiao, M.Y. Ke, Wei Ping Chen, D.H. Ni, Yuan Yuan Li
Abstract: The application of warm compaction in stainless steel powders has not been formally reported by now. In this paper, the warm compacting behavior of 316L stainless steel powders had been studied. Results showed that warm compaction was effective in improving the green density and strength of 316L stainless steel powders. Under the compacting pressure of 800 MPa, warm compacted density was 0.20 g/cm3 higher than cold compacted one, and green strength was 52% higher. The optimum warm compacting temperature was 110±10°C. With die wall lubricated warm compaction, the internal lubricant content can be reduced by 0.5 wt%.
443
Authors: Jian Cheng Fang, Wen Ji Xu, Zhi Yu Zhao
Abstract: The quality of spray-formed parts is the most important research field in plasma spraying, which has been developed in rapid forming the materials of difficult processing such as ceramics, high melting point alloy and composite materials in recent years. It is insufficient to research the forming quality affected by the plasma-particle interaction based on the plasma characteristics. The temperature field distributions of plasma jet have been investigated under the different conditions by imaging and processing, and the experimental measurements of surface temperature for in-flight particle have been carried out by the principle of two-wavelength pyrometer. At the same time, the mathematical models of momentum and energy transfer have been established to analyze the motion laws and temperature distribution of in-flight particles during spraying. The results show that the temperature field distribution of plasma jet is obviously affected by the components of working gas, the forming quality is significantly influenced by the flight time and melting state till arriving at the spray mould, in which the mechanical behavior and the heating characteristic of plasma-particle interaction in spraying system should be properly matched with each other. The mathematical simulations of temperature are in a good agreement with experimental results.
448
Authors: Yong Kang Zhang, Jian Zhong Zhou, Dun Wen Zuo, Judith C. Yang, Lan Cai
Abstract: The conventional forming of sheet metal is realized by the Die and Mould, this method usually give rise to high cost, long production periods and little flexibility. In order to adapt to the changing requirements of the market and make small batch production of three-dimensional parts of shallow stretching economically, a flexible forming technique of sheet metal based on laser shock waves is presented in this paper. After the forming mechanism and process are introduced, a finite-element analysis method is applied to simulate the shock forming process to obtain the optimized laser parameters and the shocking tracks. The experimental are carried out for the overlapped shock-forming, and the forming contour is measured and compared with the FEA simulation. The investigation provides the theoretical foundation for the selection of forming locus and processing parameters of flexible forming of sheet metal.
453
Authors: Jing Yu Pei, Chang Ning Guo, De Jin Hu
Abstract: This paper presents the tests of electrical discharge grinding (EDG) of polycrystalline diamond (PCD) on electrical discharge machine tool with high speed rotating device. The effects of wheel speed, open circuit voltage, peak current, pulse on time, and pulse off time of EDG on the material removal rate (MRR), wheel wear rate (WWR) and surface roughness (SR) are investigated respectively. The tests indicate that it is possible to shape PCD blank with EDG. The wheel speed makes the MRR increase dramatically. The higher the open circuit voltage, the larger is the MRR. The effect of peak current on the MRR, WWR and the SR is similar with that of open circuit voltage. However, the influence of the peak current is much larger than that of the open circuit voltage. Moreover, the peak current should be smaller than 32A. There is a best ratio between the pulse on time and pulse off time. If a ratio is larger or smaller than that value, there may be adverse effect on the SR and the MRR. Large pulse on time makes the MRR increase and the WWR decrease. However, all the parameters investigated have little influence on the SR of PCD. The SR is determined mainly by the grain size of PCD.
457
Authors: Jun Wang, H. Liu, Chuan Zhen Huang
Abstract: Predictive mathematical models for the depth of jet penetration are presented for both straight-slit cutting and contouring by an abrasive waterjet (AWJ). The plausibility and predictive capability of the models are assessed and verified by an experimental investigation when cutting an 87% alumina ceramic. It shows that the predictions of the models are in good agreement with the experimental data.
462
Authors: B. Huang, Zeng Wen Liu, Jian Feng Li, Jin Sheng Zhang, Z. Wang
Abstract: With the growing use of natural stone both in industrial field and in ornamental materials of building, Complex-shaped stone products are being dramatic increasing. It is necessary to machine it with flexible and automatic machines such as NC machining enters. Versatile tools such as shaped diamond mills are used. The wear mechanism of diamond mills in stone cutting is presented in this paper though experiments. The macro-geometries of diamond mills such as mill diameter, profile and weight are described. The changes of macro-geometries of shaped diamond mills can be used to express tool wears. The changes can therefore be used to forecast tool wears in stone machining.
469
Authors: Ju Long Yuan, Fei Yan Lou, Zhi Wei Wang, M. Chang, W.P. Du, Q.F. De
Abstract: Potassium Titanium Oxide Phosphate (KTP) is a new nonlinear frequency-conversion crystal. It has chemical stability, high nonlinear coefficient, high damage threshold, easily-polished surface, and a broad transparency range. It is be used in solid green laser with medium and low power widely. The requirement for surface roughness is less than 1nm.In this paper, the removal rate and surface roughness are discussed with different velocity, pressure and size of abrasive powder. In order to satisfy the requirement, new polishing techniques with ultra-precision plane polishing machine (Nanopoli-100), and fine AL2O3, SiO2 powders are proposed in this study. The final surface roughness of the KTP is less than 1nm.The machining process and characteristics are also indicated.
473
Authors: Kang Min Zhong, P.Q. Guo, Q. Chi
Abstract: The research on greenization of fixture technology is next to nothing nearly now. Approaches for greenization of fixture technology were discussed based on the analysis of energy forms and medium of fluid transmission. The feasibility that using manual fixture with multiple series supper-force-amplified device instead of power driven fixture was presented in the point of view for greenization of energy type. The working principle of manual fixture with four-step series force-amplified device, which we have invented independently, was introduced. According to the thought for greenization of medium of fluid transmission, the feasibility that employing pneumatic fixture with force-amplified device or pneumatic-hydraulic pressure-amplified device instead of hydraulic fixture. The innovated pneumatic fixture with sphere-coin two-step force-amplified device and the two-action pneumatic-hydraulic pressure-amplified device with two steps of pressure output were illustrated briefly by means of diagram.
477
Authors: Pei Qi Ge, L. Zhang, W. Gao, Zhen Chang Liu
Abstract: The endless diamond wire saw was developed using complex electroplating method. The sawing process on granite was experimented. The effects of diamond grain size, feed load, wire speed, and granite properties on sawing process were investigated. It is proved that the edges of sawing slot of granite were regulative and the cutting surfaces were smooth. The cutting efficiency could be improved by increasing the diamond grain size, wire speed, and feed load. However the increase of the feed load would induce higher tangential cutting force, and the case of the effect of wire speed was reversed.
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