A plug-in flow friction spot welding method and its tool

Abstract

The invention discloses aninsertion type flow friction spot welding method and tool. The spot welding tool comprises a backfill pin, a friction head and a compacting sleeve, which are arranged in a sleeving manner from inside to outside in sequence and slide relatively; the friction head is provided with a feed-through cavity; one or more partition boards are arranged in the feed-through cavity in the end part of the friction head axially to form at least two internal cavities; slots are formed in end parts of the backfill pin to form pin branches respectively and correspondingly matched with the internal cavities; the pin branches can slide along the internal cavities; the end surfaces of the pin branches can be positioned on the same plane with the end surface at the end part of the friction head and the end surface of the compacting sleeve. The method and the tool maintain the characteristic that a backfill type stirring friction weld nugget surface is smooth and has no key holes, and eliminate the unevenness of the internal structure of the joint.

Description

technical field [0001] The invention relates to a keyhole-less friction spot welding, in particular to a plug-in flow friction spot welding method and a tool thereof, which belongs to the technical field of point connection and is suitable for point connection of the same or different types of heat-plasticizable materials. Background technique [0002] Friction stir spot welding is a new solid-phase joining technology developed on the basis of friction stir welding with great market application prospects. Compared with connection technologies such as resistance spot welding and riveting, friction stir spot welding has the following advantages: 1. Less power consumption and low cost. Studies have shown that compared with resistance spot welding, friction stir spot welding can reduce power consumption by 99% %; 2. Compared with resistance spot welding, the joint quality is high, the defect rate is low, the deformation is small, and the welding quality is stable; 3. The working...

AI Technical Summary

Problems solved by technology

[0004] However, in the existing backfill friction stir spot welding process, because the shoulder inserted into the material to be welded cannot fully stir the entire welding spot area, the internal structure distribution of the welding zone is more complicated, and it is prone to looseness and weak spots. These problems lead to the fatigue performance of backfilled friction stir spot welded joints is not as good as that of conventional friction stir spot welded joints with keyholes, and fatigue performance is particularly important in aerospace structural parts

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