Abstract: The present paper describes the advantages, the main parameters, and the mechanism of bonding in ultrasonic welding.
By analysing the sixteen experiments by previous workers, the relations between respectively the clamped force P, the welding time τ, the displacement amplitude ξ_m, and the welding strength Q are discussed, and the critical values of P, τ, and ξ_m analysed.
For welding thicker pieces, automatic frequency control should be adopted.The mechanism of bonding is not yet completely understood. It is pointed out in the paper that three different points of view have been introduced:(1) bonding is purely a frictional process; (2) heat and plastic strain are important, with melting sometimes taking place; (3) the factors of friction, plastic strain, and heat should all be taken into consideration, but still there appears no melting phenomenon. In concluding the paper, the future trend of developement is discussed.