Earth Moving Fabrication allows significant savings in energy consumption. This low melting temperature makes it possible to use steel to make permanent molds. Aluminum has two categories of alloys: wrought alloys and foundry alloys. Foundry alloys have a higher content of alloying elements to increase their flowability in particular. They can also reduce the risk of hot cracking and reduce shrinkage cavities.
Shell molding (permanent mold)
In this process, the mold is metallic. It takes the outer shape of the room to create. The liquid aluminum alloy is poured into the cavity called imprint. The filling is done by gravity. Die casting – The liquid aluminum alloy is injected at a pressure of 70 to 100 megapascals into the mold cavity by means of a piston. The operation is fast, about 0.1 seconds on average.
Lost wax casting
The advantage of lost wax casting is to be able to create parts complexes that could not be molded otherwise, monobloc with excellent dimensional tolerance and an excellent surface finish. The principle is to mold wax parts together for Earth Moving Fabrication purposes.
Squeeze casting is a process of slowly casting thick pieces of aluminum under very high pressure into a mold. Lost Foam Molding (loss foam) – This process, little used, is distinguished by the absence of nucleus. The polystyrene model burns in contact with the liquid metal during the filling of the mold.
Semi-solid molding
In this process, the material is in the semi-solid state. Cast aluminum alloy parts are mainly used for structural applications. At the temperature of the semi-solid state, the alloy is injected into a mold. Since the viscosity of the metal is higher and the injection rate is slower, the filling of the mold is done with very little turbulence. Moreover, the pieces produced have almost no porosity.
Ablation
This process, very rare, sinks the metal in a sand mold with water-soluble binder. Before complete solidification of the aluminum, jets of water dissolve the sand and quickly cool the room, giving it excellent mechanical properties.
Machining
Machining is a process of removing material in the form of chips to obtain the desired geometries. Machining operations are grouped into three families: conventional machining, abrasive machining and non-traditional machining. The difference between these three machining families lies mainly in the type of tool used. It is possible to make rough machining and finishing machining with high precision.
Aluminum is an interesting metal for machining processes for several reasons. Firstly, cutting speeds are higher for aluminum than for steel alloys; it is then faster to machine an aluminum part. In addition, aluminum has good thermal conductivity, which reduces the temperature of the chips and the tip of the cutting tools.
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