Ultrasonic Welding 超声波焊接
超声波焊接是利用超声波或振动产生焊接热的焊接工艺。超声波是指频率高于正常听力范围的振动波。它大约是20000到30000赫兹。这是一个固态焊接过程。固态焊接是一种不需要外加热量进行焊接的焊接工艺。Ultrasonic welding is a welding process in which ultrasonic waves or vibrations are used to generate heat for welding. Ultrasonic means those vibration waves which have frequency above the normal hearing range. It is about 20000 to 30000 Hz. It is a solid state welding process. Solid state welding is a welding process in which no external heat is added for welding.
换能器是将高频电信号转换为高频机械振动的装置。这是连接到焊接头。焊接过程中使用的转换器或压电换能器。Transducer is a device which can convert high frequency electric signal into high frequency mechanical vibration. This is connected with the welding head. The converter or piezoelectric transducer used in this welding process.
它的工作原理是超声波能量的基本原理。超声波振动在两个工件的触点之间产生动态剪切应力。由于局部塑性变形和由于接触表面之间的摩擦而产生的热量，将在界面处形成接头。It works on the basic principle of energy of ultrasonic wave. Ultrasonic vibration creates a dynamic shear stress between the contacts of two work piece. Due to local plastic deformation and heat generate due to friction between contact surfaces, joint formation will take place at the interface.
At the start, high frequency current passes through a piezoelectric transducer. This transducer converts high frequency electrical signal into mechanical vibration.
This vibration further supplied to the booster which amplify its frequency.
The amplified high frequency vibration passes through horn which is in contact with welding plate.
This welding creates lap joint. One plant of the weld is fixed into fixture and other one is in direct contact with horn. These plates are fixed under moderate pressure force.
The horn supply high frequency mechanical vibration to the welding plate.
Due to this vibration, oscillation shear force act at the interface between welding plates which result elestoplastic deformation at interface.
It also create a localize temperature rise due to mechanical force and friction. This heat helps in plastic deformation at interface and makes a strong joint without melting of work piece or using filler metal.
This welding is used in fabrication of nuclear reactor components.
It is used in automotive industry for key, head lamp parts, button and switches etc.
Ultrasonic is used in electronic industries like armature winding, switches etc.
This is clean welding process so it is used in medical industries to make parts like filters, masks etc.
- This welding is used in fabrication of nuclear reactor components.