| “Figure of eight” is a safety device that is used to descend from a certain height safely. Using the principle of friction on the surface and tension straps on the both sides allows the user to hold the weight fall. Materials used must be lightweight and strong, resistant to surface friction and corrosion on the surrounding environment, and will not deform the rope used. Al 6082-T6 material selected for having highly forgeability and formability, and the strength that is able to be improved through heat treatment become an additional factor. Great speed and loading existing friction, affects the amount of wear that occurred. Friction on the surface of the “figure of eight” over time will erode the coating and resulting the aluminum metal exposed to the surrounding environment, but the Al2O3 film layer that formed enables aluminum to be protected both from friction or corrosive environments. High conductivity values are also chosen because it has ability to deliver heat, so the heat transfer occurs rapidly and does not allow the occurrence of phase changes due to temperature rise. The chemical composition also affects its strength, the bond between the elements Mg and Si that generates Mg2Si enough to make aluminum are at the level of medium strength. |