Figure 1. Tool for friction drilling in the mandrel of the machine; b. Detail of the clamping xture. In a series of experiments of this project, the following category of welding materials has been approached by the friction stir welding (FSW) process, as a friction processing method: aluminum alloys in a dissimilar joint with pure electrotechnical copper for the purpose of making connections for electrical installations [2]. From this category, experiments were carried out for the following representative alumi- num alloys: Al 99, respectively EN AW 1200 aluminium alloy, usable in electrical engineering; EN AW 5754 aluminium alloy, especially usable in machine production, manufacturing industry for various parts, etc.; EN AW 6082 aluminium alloy, usable in particular in civil engineering, road and rail transport, etc.; as well as EN AW 7075 aluminium alloy, widely used in the aeronautical and nuclear elds. Research on rivet joining techniques currently concern the internatio- nal scienti c community in the eld, which is reinforced by scienti c papers published in the main ow of information, namely patents pro- tected in advanced countries [5]. The focus is on research of joining processes, on their mathematical modeling, joints characterization, process monitoring, as well as the identi cation of new applications, particularly in priority areas. Worldwide, there is interest in the industrial environment to implement research into new methods of joining by riveting especially in the auto- motive industry, aviation, railway, construction. Assembly operations by riveting are used especially where, for various reasons, welded joints are not recommended: the construction of com- ponents for aircraft, automotive components, construction of bridges, truss, bodywork, in rail transport - by carriage fabrication, etc. [5]. In sum, riveting joining techniques are indicated for joints subjected to vibration loads or to high dynamic efforts, weld assembly of metals dif cult to weld, assembly of metal constructions pro les or assem- blies of parts from different materials. Friction drilling Friction or form drilling (FD) process [1-2] is a non-conventional process to make holes on metal sheets. It is an alternative process, compared to conventional drilling. It is based on the material ow, by using the heat caused by the friction of a conical shape rotary tool without cutting edges. The FD tool has two different sections: a conical surface that penetrates the hole and softens the sheet material and a cylindrical segment that produces the nal hole diameter. As a result, a signi cant burr appears at the hole exit, the so-called cup. Burrs are undesirable in common machining operations, because they reduce machined part quality. But FD takes advantage of burrs, as they pro- duce the cup that eliminates the need of using a nut in the joint, since threading is applied on the cup inner surface. Recently, in the frame of the project J-FAST [2], some experiments have been performed on a dissimilar joint of a square-section tube (50 x 50 mm) of S235 steel, according to EN 10 025, to be surfaced with sheets of Al 5754 (thickness=1.0 mm). Regarding friction drilling tools, in all the cases, carbide tools (90% WC and grain size 1 micron), Ø 4.3 mm were employed in order to achieve M5x0.8 (Figure 1). The clamping xture for the experiments is also shown. Form tapping for threading The holes need to be threaded by form tapping [1-3]. Regarding the tool, taps have often polygonal geometries with at least ve lobes. Taps are often made of HSS coated with titanium nitride (TiN) to provide a core with enough toughness, but harder surface. In some cases, anti- friction coatings or internal lubrication are advisable. Also, they may include tapered cutting edges with smaller diameter to initiate the material removal. According to the hole machined with the Ø 4.3 form tool, a form tap for M5 was selected fo threading. Assembly operations by riveting are used especially where welded joints are not recommended MATERIALS >>39