The intelligent processing of materials: An overview and case study

Wadley, H.N.G.; Vancheeswaran, R.

doi:10.1007/s11837-998-0063-6

Cited by 6 publications

(1 citation statement)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, this process appears well suited for the application of what has come to be known as intelligent processing of materials concepts. [31] In this now widely practiced approach, sensors are used to continuously monitor structure and process models are combined with feedback control principles to regulate the process variables in such a way that a desired material state is achieved. Radiography, [32] eddy current [33] or laser ultrasonic [34] sensors all appear well suited for monitoring relative density and interring cell size, even in the harsh environment of the foaming process.…”

Section: Stochastic Foamsmentioning

confidence: 99%

Cellular Metals Manufacturing

Wadley¹

2002

Adv. Eng. Mater.

241

View full text Add to dashboard Cite

Manufacturing Methods OverviewAs the engineering applications of cellular metals grows, many methods for their manufacture are being developed. [1] They result in materials that can be classified by the size of their cells, variability in cell size (stochastic or periodic), the pore type (open or closed) and the relative density of the structure. Figure 1 summarizes the range of cell size and relative density for materials created by established and emerging manufacturing methods. Those with high relative density, r/ r s >0.5 (where r is the cellular metals density and r s is that of the solid from which it is made) include Gasars made by the solidification of metal-H 2 alloys [2] and expanded, entrapped gas materials. [3] Interest in the structural uses of both materials has declined because of the difficulty of creating the low relative densities (0.05±0.20) needed for these applications. [4] Manufacturing methods based upon the foaming of a liquid metal, either by injecting a gas (the CYMAT process) [5] or by the decomposition of gas releasing particles (e.g. the Alporus or Alulight materials) [6] are the most widely used for making stochastic cellular aluminum. Efforts are underway to extend the method to other metals. Both approaches result in closed cell stochastic foams with cell sizes in the 0.5 to 15 mm range and relative densities from 0.04 to 0.4.Open cell, stochastic nickel foams are widely used for the electrodes and current collectors of metal ± metal hydride batteries. Closed cell, periodic aluminum honeycomb is extensively used for the cores of light, stiff sandwich panel structures. Interest is now growing in other cell topologies and potential applications are expanding. For example cellular metals are being evaluated for impact energy absorption, for noise and vibration damping and for novel approaches to thermal management. Numerous methods for manufacturing cellular metals are being developed. As a basic understanding of the relationships between cell topology and the performance of cellular metals in each application area begins to emerge, interest is growing in processes that enable an optimized topology to be reproducibly created. For some applications, such as acoustic attenuation, stochastic metal foams are likely to be preferred over their periodically structured counterparts. Nonetheless, the average cell size, the cell size standard deviation, the relative density and the microstructure of the ligaments are all important to control. The invention of more stable processes and improved methods for on-line control of the cellular structure via in-situ sensing and more sophisticated control algorithms are likely to lead to significant improvements in foam topology. For load supporting applications, sandwich panels containing honeycomb cores are much superior to those utilizing stochastic foams, but they are more costly than stochastic foam core materials. Recently, processes have begun to emerge for making open cell periodic cell materials with triangular or pyramidal truss topologies. Th...

show abstract