Mass and Section Thickness

There are limits to the size of component that a process can make. Figure 18.3 shows the limits. The color coding for material compatibility has been retained, using more than one color when the process can treat more than one material family. Size can be measured by volume or by mass, but since the range of either one covers many orders of magnitude, while densities only span a factor of about 10, it doesn't make much difference which we use big things are heavy, whatever they are made of. Most processes span a mass range of about a factor of 1000 or so. Note that this attribute is most discriminating at the extremes; the vast majority of components are in the 0.1 10 kg range, for which virtually any process will work.

Figure 18.3: The process-mass range bar chart for shaping processes. Ignore, on first reading, the boxes; they refer to case studies to come. The colors refer to the material, as in Figure 18.2. Multiple colors indicate compatibility with more than one family.

It is worth noting what the ranges represent. Each bar spans the size range of which the process is capable without undue technical difficulty. All can be stretched to smaller or larger extremes but at the penalty of extra cost because the equipment is no longer standard. During screening, therefore, it is important to recognize 'near misses' processes which narrowly failed, but which could, if needed, be reconsidered and...