Work interface accessory, work kit and friction stir welding method

A work kit, comprising a work interface accessory and a friction stir welding head, wherein the work interface accessory, which is intended to be assembled on a friction stir welding head and which is able to be disassembled relative to the friction stir welding head,

• wherein the work interface accessory comprises an external body having a first side wall delimiting a first recess open on top for introduction of a rotating portion of the friction stir welding head in the first recess and for withdrawal of the friction stir welding head out of the first recess,
• the work interface accessory comprises an upper plate, which is fastened on an upper portion of the first side wall or which is integral with the upper portion of the first side wall, which has a first upper opening connected to the first recess and which comprises fastening portions, allowing removable fastening against the friction stir welding head,
• the work interface accessory comprising a central shaft, which is rotatably assembled in the first side wall around an axis of rotation,
• the central shaft having a second lower portion, which projects from a first lower portion of the first side wall downwards and which is intended to carry a work tool,
• the central shaft comprising in the first recess an internally toothed coupling sleeve to allow the central shaft to be driven in rotation, when an externally toothed ring gear of the rotating portion of the friction stir welding head is introduced into the internally toothed coupling sleeve and rotates in the internally toothed coupling sleeve around the axis of rotation,
• wherein the friction stir welding head comprises a frame and the rotating portion, rotatably assembled relative to the frame and protruding therefrom downwards,
• the frame comprising a second plate for bearing against the upper plate,
• the second plate comprising a gripping mechanism comprising a system of clamps, which is facing downwards and which is intended to be fastened on the fastening portions of the upper plate of the work interface accessory, or the fastening portions of the upper plate of the work interface accessory comprising a gripping mechanism comprising a system of clamps, which is facing upwards and which is intended to be fastened on other fastening portions of the second plate of the friction stir welding head,
• wherein the fastening portions of the upper plate of the work interface accessory each comprise a pull tab, which is facing upwards and which is fastened to the upper plate, or the other fastening portions of the second plate of the friction stir welding head each comprise a pull tab, which is facing downwards and which is fastened to the second plate,
• wherein the clamps are actuatable by a pressurized fluid or electrically or mechanically or hydraulically or magnetically to be either in a position of gripping the fastening portions, or in a position of releasing the fastening portions.