Microstructure features

Fig. 16.7. Microstructural features of a crystalline ceramic grains, grain boundaries, pores, microcracks and second phases.

And so, as you can see from the Contents list, the chapters are arranged in groups, with a group of chapters to describe each of the four classes of materials. In each group we first introduce the major families of materials that go to make up each materials class. We then outline the main microstructural features of the class, and show how to process or treat them to get the structures (really, in the end, the properties) that we want. Each group of chapters is illustrated by Case Studies designed to help you... 

The type of manufacturing process, reaction conditions, and catalyst are the controlling factors for the molecular structure of the polymers [4-8]. The molecular features govern the melt processability and microstructure of the solids. The formation of the microstructure is also affected by the melt-processing conditions set for shaping the polymeric resin [9]. The ultimate properties are, thus, directly related to the microstructural features of the polymeric solid. 

Finally, it should be noted that in both cases the effect of crystal defects and microstructural features must, in general, be to tend to make the corrosion less uniform and more localised. 

The physico-chemical microstructural features leading to common classification... 

Favorable rheological properties are an essential requirement for the commercialization of polyolefins like polyethylene. The ease of processability of the polymer melt, obtained through modifications in the microstructural features, is as important as the end use mechanical properties of these polymers. Presence of long-chain as well as short-chain branching, LCB and SCB, respectively, more or less dictates the rheological behavior of most commercial... 

S. Sumiya, T. Irifune, A. Kurio, S. Sakamoto, and T. Inoue, Microstructure Features of Polycrystalline Diamond Synthesized Directly from Graphite under Static High Pressure , Jour. Mater. Sci., 39,445 (2004). 

La O GJ, Hertz J, Tuller H, and Shao-Hom Y. Microstructural features of RF-sputtered SOFC anode and electrolyte materials. J. Electroceram. 2004 13 691-695. 

V-Ti-Ni alloys and Fe- /Co-Based metallic glasses have been evaluated with respect to hydrogen permeability for potential use in hydrogen purification membrane reactor application. Microstructural characterization of the V-Ti-Ni alloy using SEM has shown similar microstructural features to a previously evaluated Nb-Ti-Ni alloy namely, the occurrence of a primary phase surrounded by interdendritic eutectic. 

The separation efficiency (e.g. permselectivity and permeability) of inorganic membranes depends, to a large extent, on the microstructural features of the membrane/support composites such as pore size and its distribution, pore shape, porosity and tortuosity. The microstructures (as a result of the various preparation methods and the processing conditions discussed in Chapter 2) and the membrane/support geometry will be described in some detail, particularly for commercial inorganic membranes. Other material-related membrane properties will be taken into consideration for specific separation applications. For example, the issues of chemical resistance and surface interaction of the membrane material and the physical nature of the module packing materials in relation to the membranes will be addressed. 

---