Ultrasonic processes welding

FIGURE 14.11 Equipment used in standard ultrasonic welding process. 

J. Park, J. Liddy, Effect of paint over spray for vibration and ultrasonic welding processes. SPE, ANTEC 62nd Annual Technical Conference (2004)... 

Figure U.2 Equipment used in a standard ultrasonic welding process. (Ref Grim, R.A., Welding Process for Plastics , Advanced Materials and Processes, March 1995)...

Figure 8.8 Stages in the ultrasonic welding process. In Phase 1, the horn is placed in contact with the part, pressure is applied, and vibratory motion is started. Heat generation due to friction melts the energy director, and it flows into the joint interface. The weld displacement begins to increase as the distance between the parts decreases. In Phase 2, the melting rate increases, resulting in increased weld displacement, and the part surfaces meet. Steady-state melting occurs in Phase 3, as a constant melt layer thickness is maintained in the weld. In Phase 4, the holding phase, vibrations cease. Maximum di lacement is reached, and inter-molecular diffusion occurs as the weld cools and solidifies. ...

Rules for the welded fabrication of pressure vessels cover welding processes, manufacturer s record keeping on welding procedures, welder qualification, cleaning, fit-up alignment tolerances, and repair of weld defects. Procedures for postweld heat treatment are detailed. Checking the procedures and welders and radiographic and ultrasonic examination of welded joints are covered. 

Welding is easy using thermal processes and possible by the high-frequency technique if the VA content is above 13%. Ultrasonic welding is suitable for thin parts. 

There are at present only a few commercial applications of ultrasound in the plastics industry. The best knovm is probably the welding of thermoplastics, a process which now lends itself readily to automation. In common with the welding of metals, the ultrasonic welding of plastics is primarily a hot stage. In the process ultrasound is applied to two layers of plastic, heat is generated at the interface causing the material... 

Ultrasonic welding, used increasingly in the aerospace, automotive, electrical, and electronics industries. The process requires simpler surface preparation and less energy and allows welding of thinner sheets to thicker structural members. 

Ultrasonic welding is a frictional process that has been well established for heat welding thermoplastic parts. Like induction welding, it also has been adapted for curing structural adhesives such as epoxy. 

Ultrasonic welding the two basic techniques are plunge welding and continuous welding. In plunge welding, the parts are placed under a tool or horn the horn descends to the part under moderate pressure and the weld cycle is initiated. In the continuous welding process, the horn may scan the part or the material is passed over or under the horn on a continual basis. 

For Direct Tooling LLM results in the so-called lamella tools composed from a set of single layers of some millimeters thickness, joint by ultrasonic welding or mechanically. This rapidly processes massive tools. But they show limited details and need intensive postprocessing of its surface. The imprint of the stair steps can be avoided by covering the tool with deep throwing foil. 

Fabrisonic (MI, USA) introduced a hybrid milling and ultrasmiic welding machine that makes dense ahuninum parts based on their so-called ultrasonic consolidation process. 

Ultrasonic welding is a sohd-state process in which the actual bonding between the two parts to be welded is obtained through the decaying into heat of the fi-iction forces work. The latter are generated by a vibration induced by an ultrasonic transducer. As it is well known, ultrasonic elastic waves are characterized by frequencies which can reach 10 kHz. To obtain the welding, electromechanical generators are used ... 

Another process in which mechanical energy is transformed into heat is ultrasonic welding, which is illustrated in Figure 8.9. A piezoelectric crystal transmits longitudinal vibrations at a frequency of about 20 kHz through... 

Carbon fiber reinforced PEI thermoplastic floor panels have been developed for the Gulfstream V corporate jet, replacing a heavier A1 design [167]. The floor panels eomprised preconsolidated carbon fiber/PEI skins bonded to each side of a Nomex/phenolie honeyeomb and processed by thermoforming and ultrasonic welding. 

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