Rivets Mold

Last week, the rivets dimensions were recalculated acording to the resultes of traction test. Therefore, a mold was designed in CAD 3D. The team decided to use a permanet mold, once it provides a better surface finishing, uniformity and a smaller dimensional tolerance. Besides, the mold will bem ade of steel, whose melting point is higher than the melting point of the aluminum.

Figure 1 - Rivets body mold

Source: Own

Figure 2 - Rivets head mold

Source: Own

The team intends to manufacture the cavities using drills, and cut the mold in the middle right after to make easy the remotion of the rivets. The cavity for the rivet head will bem ade in a 3rd parto f the molde, as shown in figure 3.

Figure 3 - Exploded view of the metalic mold

Source: Own

Besides, the team looked for drills in Theoprax Lab and the diameter choosen was 8,5mm, because, acording to the calculations, the rivet body must have a diameter of 8,25mm. Thoses dimensions must include how much the molten aluminum will contract during its crystallising. The dimensional tolerance of the project is ± 5%, so the dimensions won’t be bigger than that. 

Posted by: Luana Seixas

Bibliography:

CHIAVERINI, V. Tecnologia Mecânica. Processos de Fabricação e Tratamentos. Volume II. Editora Makron Books. 1986.