cross section crash boxes

Figure 2. 9. Schematic of the foaming powder compact process.
Two factors affect the foaming cost: the production volume and production cost
(Maine and Ashby 2000). No matter how high is the volume production of powder
metallurgical processing of Al foam, the batch or continuous production methods
cannot reach the liquid state production cost at increasing volumes as shown in Figure
2.10. Higher production cost of foaming powder compacts process is caused by the
higher number of production steps involved and the more expensive powder form of Al
used in the process. However, foaming powder compacts process has an important
advantage over the liquid based foaming processes. In the foaming powder compacts
process, the foam can be produced in near net shape with a naturally occurring dense
skin layer to which various kinds of finishing processes such as sand blasting and
polishing can be easily applied. This may compensate its higher cost at high volume
productions when the shaped products are required by the customers. The other
advantages of the method include its flexibility in alloy selection, the availability of
manufacturing composite structures, no need for particle stabilization and possibility of
reinforcement with ceramics or fiber (Baumgärtner, et al. 2000).
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