Studies in Materials Selection

In this chapter we present some case studies that will allow us to examine how the concepts we have described in the previous chapters can be applied to solving real, materials-related problems. We begin with a description of some basic design principles, which will lead into how they can be adapted to materials selection. 

An Introduction to Materials Engineering and Science For Chemical and Materials Engineers, by Brian S. Mitchell 

We will not describe the iterative design process in any more detail than this. There are many fine books on the subject, and the interested reader is referred to the list at the end of the chapter for further information. After a brief diversion into alternative design strategies in the next section, we will return to the iterative design process to see how the concepts of materials selection fit into mechanical design. 

2 Concurrent Engineering. Concurrent engineering, sometimes called 

Just in time (JIT) domino.watson.ibm.com/cambridge/research.nsf/pages/papers.html 

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M, F. Ashby and D. Cebon, Case Studies in Materials Selection, Granta Design, Cambridge, 1996. S. Marx and W. Pfau, Observatories of the World, Blandford Press, Poole, Dorset, 1982 (for telescopes). 

M. F, Ashby and D. Cebon, Case Studies in Materials Selection, Granta Design, Cambridge, 1996. 

A first aim in the present study was to establish whether the approach proposed by Femlund Spelt, which will be described in more detail below, could be applied to bonded composite joints. A second objective was to evaluate the benefits to be gained from a fracture mechanics characterisation when industrial structural assemblies are considered, both qualitatively in material selection, and quantitatively when failure predictions are required. 

Clarke, I.C. (1982) Wear-screening and joint simulation studies vs. materials selection and prosthesis design. CRC Crit. Rev. in Biomed. Eng., 8, 29-91. 

Scott G, Gilead D (1995) Degradable polymers. Chapman Hall, London Copinet A, Bertrand C, Longieras AY et al (2003) Photodegradation and biodegradable study of a starch and poly(lactic acid) coextruded material. J Polym Environ 11 169-176 Thurston D, Lloyd S, Wallace J (1994) Considering consumer preferences for protection in material selection. Mater Des 15 203-209... 

Because of the technological importance of supercritical aqueous solutions, as evidenced by their use as reaction media in the destruction of toxic waste and as a heat transport medium, it is not surprising that the corrosion of stmctural materials has been studied in some depth. This is especially tme recognizing the well-known aggressiveness of supercritical aqueous solutions, which raises great challenges in materials selection. Indeed, it is likely that SCWO and SCTPPs will continue to drive the development of the science and engineering base of the corrosion of metals and alloys in supercritical aqueous solutions over the foreseeable future. 

Single-reaction-step processes have been studied. However, higher selectivity is possible by optimizing catalyst composition and reaction conditions for each of these two steps (40,41). This more efficient utilization of raw material has led to two separate oxidation stages in all commercial faciUties. A two-step continuous process without isolation of the intermediate acrolein was first described by the Toyo Soda Company (42). A mixture of propylene, air, and steam is converted to acrolein in the first reactor. The effluent from the first reactor is then passed directiy to the second reactor where the acrolein is oxidized to acryUc acid. The products are absorbed in water to give about 30—60% aqueous acryUc acid in about 80—85% yield based on propylene. 

In the absence of factual corrosion information for a particular set of fluid conditions, a reasonably good selection would be possible from data based on the resistance of materials to a very simifar environment. These data, however, should be used with some reservations. Good practice calls for applying such data for preliminary screening. Materials selected thereby would reqmre further study in the fluid system under consideration. 

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