Ultrasonic Welding 超聲波焊接
超聲波焊接是利用超聲波或振動產生焊接熱的焊接工藝。超聲波是指頻率高于正常聽力范圍的振動波。它大約是20000到30000赫茲。這是一個固態焊接過程。固態焊接是一種不需要外加熱量進行焊接的焊接工藝。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.
換能器是將高頻電信號轉換為高頻機械振動的裝置。這是連接到焊接頭。焊接過程中使用的轉換器或壓電換能器。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.
它的工作原理是超聲波能量的基本原理。超聲波振動在兩個工件的觸點之間產生動態剪切應力。由于局部塑性變形和由于接觸表面之間的摩擦而產生的熱量，將在界面處形成接頭。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.