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Gu X.Y.,Tianjin University | Li H.,Tianjin University | Gao Y.,Tianjin Key Laboratory of High Speed Cutting and Precision Machining
Applied Mechanics and Materials | Year: 2013

AZ31 magnesium alloy was welded by the YAG laser. The plasma of laser welding was studied by the spectra and the plasma temperature was also calculated. The relationship between the welding parameters and plasma temperature was studied. The paper shows that the cooling effect of the plasma using helium is significant. Laser plasma temperature decreases from the center to the periphery and the temperature in the center is higher than 9000K. The evaporation of Mg element concentrates in the center of the laser plasma. © (2013) Trans Tech Publications, Switzerland. Source


Gu X.,Tianjin University | Li H.,Tianjin University | Yang L.,Tianjin University | Gao Y.,Tianjin Key Laboratory of High Speed Cutting and Precision Machining
China Welding (English Edition) | Year: 2012

In this study, multi-information including spectrum, high-speed photograph and electrical signal was adopted to explore the coupling mechanism of alternate burning in laser-twin-arc welding process. Laser provides a conductive, stable plasma channel for arcs. Plasma radiation strengthened especially in the center of the arc after hybrid. High temperature plasma erupting from keyhole provides an upward reacting force which can prevent droplet from transfer. The charged particles consisted in high temperature plasma reduce the voltage that maintains arc ignition or burning. The results show that laser can influence the arc shape, prevent droplet transfer, reduce resistivity and stabilize arcs. © 20120Editorial Board of CHINA WELDING. Source


Zhao H.,Tianjin University of Technology and Education | Cai Y.J.,Tianjin Key Laboratory of High Speed Cutting and Precision Machining
Applied Mechanics and Materials | Year: 2014

In this paper, a very detailed process analysis for UAV integral impeller was made. According to the specific processing requirements, the appropriate CNC machine, blank and cutting tools have been choosing. In the rough machining process, various machining strategies have been used for comparing and analyzing, finally a more efficient roughing method with the accurate machining parameters will be obtained. At the same time the machining method have been improved and the processing parameters also have been determined in the semi-finishing process. Through the simulation processing in VERICUT, the possibility of the existence of interference which is usually occurred in the actual processing can be ruled out and the program optimization will be finished in the meantime. Finally, using intelligent three-coordinate measuring machine the consequence will be verified and inspected in the actual machining process. © (2014) Trans Tech Publications, Switzerland. Source


Shihai Z.,Tianjin University of Technology and Education | Zimiao Z.,Tianjin Key Laboratory of High Speed Cutting and Precision Machining
Journal of Advanced Mechanical Design, Systems and Manufacturing | Year: 2015

The unbalancing vibration monitoring and control of rotating machinery is an important engineering problem. In order to correct the unbalance of rotor system online, an active dynamic balancing head is designed based on the ratchet-pawl mechanism and pneumatic technology. The inner mass distribution state of balancing head can be changed to correct the unbalance when the rotor system is working in unbalancing condition. The mechanical principle and pneumatic control system of the balancing head are introduced in th e paper. Based on a double-face online dynamic balancing experiment system, the balancing effect of the balancing head has been proved by many experiments. In order to improve the dynamic balancing accuracy of the balancing head in the practical application, the possible influencing factors of dynamic balancing accuracy are analyzed in the paper. © 2015 The Japan Society of Mechanical Engineers. Source


Gu X.,Tianjin University | Li H.,Tianjin University | Yang L.,Tianjin University | Gao Y.,Tianjin Key Laboratory of High Speed Cutting and Precision Machining
Optics and Laser Technology | Year: 2013

Laser-twin-arc hybrid welding, which combines the techniques of laser welding and twin-arc welding, is an emerging welding technology. In this study, synchronous information including spectral signal, high-speed photography and electrical signal is used to explore the physical interaction between the arcs and the laser of alternate burning in laser-twin-arc hybrid welding process, and the effect of the combined arc/laser heat source on the welding process was analyzed. The results indicated that the laser provides a conductive, stable plasma channel for the arcs, which can influence the arc shape, slow down droplet transfer, reduce resistivity and stabilize arcs. Electron temperature of hybrid arc plasma is from 7000 K to 17000 K, which is significantly influenced by laser parameters. The laser-twin-arc hybrid welding acquires deeper penetration and wider HAZ than with the twin-arc welding alone. © 2012 Elsevier Ltd. Source

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