scholarly journals Microstructure and Mechanical Properties of Resistance Heat-Assisted High-Power Ultrasonic Dissimilar Welded Cu/Al Joint

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 873 ◽  
Author(s):  
Li ◽  
Cao
Keyword(s):  
Mechanical Properties ◽  
High Power ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Hybrid Welding ◽  
Research Attention ◽  
Microstructure And Mechanical Properties ◽  
Power Ultrasonic ◽  
Average Shear ◽  
Significant Research

The Cu/Al dissimilar joint, welded by high-power ultrasonic welding technology, is still facing challenges despite the significant research attention it has attracted. In this work, the microstructure and mechanical properties of resistance heat-assisted high-power ultrasonic welding of Cu/Al are investigated, in order to obtain high-quality joints. The intermetallic compound (IMC) at the interface of hybrid welding is primarily composed of Al2Cu, and the additional resistance of heat reduces the thickness of this brittle IMC layer. The average shear stress for the joint prepared by hybrid welding is ~97 MPa, which is higher compared to the joint strength without resistance heat (90 MPa). Moreover, the duration of the hybrid welding process is shorter. Finally, the fracture of the hybrid weld is found to be a brittle–ductile hybrid mode.

Automatic Frequency-Tracking Control for Ultrasound Welding System

2011 ◽  
Vol 204-210 ◽  
pp. 2041-2044
Author(s):  
Kao Feng Yarn ◽  
King Kung Wu ◽  
Kai Hsing Ma ◽  
Wen Chung Chang
Keyword(s):  
High Power ◽  
Tracking Control ◽  
Control Method ◽  
Ultrasonic Welding ◽  
Automatic Frequency ◽  
Frequency Tracking ◽  
Power Ultrasonic ◽  
Fpga Chip ◽  
Working Frequency ◽  
Welding System

A new frequency-tracking control method to catch the optimal working frequency for the high power ultrasonic welding system is proposed. In a high power ultrasonic resonant system, the induced high temperature will change the working frequency. Therefore, the proposed control method to track the optimal working frequency becomes very attractive and important. This control method is practically implemented by a FPGA chip which basically includes two logic circuits. One logic circuit is to find the optimal working frequency automatically and the other one is to adjust the working frequency by detecting the working current simultaneously. Experimental results exhibit the new method can effectively control and track frequency for high power ultrasonic welding system.

Dissimilar Friction Stir Lap Welding of AA2198 and AA7075 Sheets: Forces, Microstructure and Mechanical Properties

2021 ◽  
Author(s):  
Antonello Astarita ◽  
Fausto Tucci ◽  
Alessia Teresa Silvestri ◽  
Michele Perrella ◽  
Luca Boccarusso ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Processing Parameters ◽  
Processing Parameter ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Lap Shear ◽  
Microstructure And Mechanical Properties ◽  
Lap Welding ◽  
Factorial Design Of Experiments

Abstract This paper deals with the dissimilar friction stir lap welding of AA2198 and AA7075 sheets. The influence of processing parameters, namely welding speed and tool rotational speed on joint features, microstructure, and mechanical properties were investigated implementing a full factorial design of experiments. During the welding process, axial and transversal forces were continuously measured using a dedicated sensed fixture aiming at the correlation of this processing parameter with the quality of the achieved joints. The reported outcomes showed a very narrow processing window in which it was possible to avoid the formation of defects while the formation of an hook was observed for all the joints welded. The influence of the weld bead morphology on the lap shear strength was elucidated proving that the strength is ruled by the hook morphology. A correlation between the process parameters and the forces arising was also attempted. The final microstructure of the joints was studied and explained and also compared with the microhardness results.

The Influence of Pulse Width on Microstructure and Mechanical Properties of CrNx Coatings Deposited by HPPMS

2014 ◽  
Vol 633 ◽  
pp. 398-401
Author(s):  
Xiang Min Xu ◽  
Hao Zhang ◽  
Yi Bin Jin ◽  
Hao Chen Zhao ◽  
Shu Wang Duo
Keyword(s):  
Mechanical Properties ◽  
Magnetron Sputtering ◽  
High Power ◽  
Pulse Width ◽  
Pulse Length ◽  
Closed Field ◽  
Power Pulse ◽  
Phase Structures ◽  
Microstructure And Mechanical Properties ◽  
High Power Pulse

CrNx coatings were deposited by high power pulse magnetron sputtering in a closed field unbalanced system. The influence of pulse width on microstructure and mechanical properties of CrNx coatings was examined. Morphologies different from those fabricated by traditional magnetron sputtering were obtained, phase structures were also changed in the process. The coatings hardness were always improved in the increasing pulse length, while the best adhension of CrNx coatings about 25N was get when pulse length was 60us.

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