Application for Optimization of Laser Beam Welding by Ultrasonic Wave Superposition

The poten­tial of ultra­son­ic wave super­po­si­tion to improve the prop­er­ties of laser beam weld­ing was inves­ti­gat­ed using sta­tion­ary and mov­ing Piezoshak­er-Sys­tem at the Depart­ment of Cut­ting and Join­ing Man­u­fac­tur­ing Process­es (tff) at the Uni­ver­si­ty of Kas­sel. An exam­ple of this is the test on the high-strength steel alloy 22MnB5, which is pre­sent­ed here. Adap­ta­tion to oth­er weld­ing process­es and mate­ri­als is possible. 

The influ­ences of the var­i­ous exci­ta­tion para­me­ters of the Piezoshak­er on the ultra­son­ic wave super­po­si­tion were inves­ti­gat­ed, e.g. the dis­tri­b­u­tion of the AlSi-coat­ing par­ti­cles with­in the join­ing zone as well as the weld seam prop­er­ties [1].

The isi-sys Piezoshak­er-Sys­tem was used for the mov­ing wave super­po­si­tion, as shown in Fig. 1 The sys­tem con­tains a 2‑channel Piezoam­pli­fier of the HPDA‑0–180-2C series and two Piezoshak­ers of the PS-W-02 series. The Piezoshak­ers are firm­ly con­nect­ed to the laser optics via a mount and are moved rel­a­tive to the com­po­nent sur­face at a defined dis­tance from the laser beam. These are pressed onto the com­po­nent sur­face with a defined force using pneu­mat­ic cylin­ders. Uneven­ness and dif­fer­ences in the thick­ness of the join­ing part­ners can be compensated.
















Fig. 1 (left): The dis­tri­b­u­tion of the AlSi-coat­ing in com­par­i­son with­out (a) and © and with (b) and (e) influ­ence of an ultra­son­ic wave super­po­si­tion by isi-sys Piezoshak­er dur­ing laser beam weld­ing with false-col­or images of EDS-analy­sis (d) and (f) [1]

Fig. 2 (right): Super­im­posed SEM-images and sec­tioned inverse pole fig­ure map­pings (IPFM) of a weld seam with­out (a) and with ultra­son­ic super­po­si­tion (b) mea­sured with elec­tron backscat­ter dif­frac­tion shown as inverse pole fig­ure in Z‑direction [1]

[1] Pub­lished in: C. Wolf, S. Völk­ers, I. Kryukov, M. Graß, N. Som­mer, S. Böhm, M. Wun­der, N. Köh­ler und P. Mäck­el, „Enhance­ment of Weld­abil­i­ty at Laser Beam Weld­ing of 22MnB5 by an Entrained Ultra­son­ic Wave Super­po­si­tion,“ In: Mate­ri­als 2022, Bd. 15, 4800.