We, JLMP team members, after designing the
riveted joints, decided to go deeper into the fabrication of our rivets.
Firstly, we try to know if the casting method used to make the specimens is
also ideal for the manufacture of rivets.
Sand molding, even though it is the cheapest of
all casting methods, requires a model construction with the same or similar
shape of the part to be cast, as well as accumulating some defects such as the
inclusion of mold sand in the walls internal or external of the part, forming
porosities.
The rivets
to be designed will be of relatively small dimensions, in this way, the chosen
method must be of good dimensional stability, besides reducing the defects
found in the worked specimen.
Analyzing
the projects of past teams, studies related to the Discipline of Foundry
Process and some researches, our team decided to opt for casting method with
metallic mold.
The
advantages of the metal mold over the green sand mold are better surface
finish, higher uniformity, narrower dimensional tolerances with finer sections,
better mechanical properties, high durability of the molds (mold cavity) and
high production capacity.
The use of
the metal molds is restricted to metals with a lower melting temperature than
iron and steel. These metals are represented by alloys with lead, zinc,
aluminum, magnesium, certain brass and, exceptionally, cast iron.
Here is an
example of a metal mold, our team is still looking for the materials needed to
make the mold, so we can start producing our rivets.
Figure 1: Example of a metal mold.
Source: Exata peças.
Nenhum comentário:
Postar um comentário