Microstructural evolution grain growth

The ratio of additive combinations also influences the microstructural evolution. For instance, with decreasing ratio of Y203/Al203 the microstructure becomes finer and the aspect ratio lower [301, 302]. MgO as well as CaO additives accelerate the grain growth and increase the aspect ratio [303, 304]. 

Chen KN, Fan A, Tan CS, Reif R. Microstructure evolution and abnormal grain growth during copper wafer bonding. Appl Phys Lett 2002 81(20) 3774-3776. 

The discussion will be rounded out by our taking stock of microstructural evolution as seen from the more traditional metallurgical viewpoint. In particular, grain growth will be taken up from a theoretical perspective. This discussion should be seen as a continuation of those given in the previous chapter since the attempt to understand these phenomena rests heavily on a synthetic understanding of point, line and interfacial defects in concert. Our contention will be that despite the exertion of Herculean efforts, a number of key difficulties remain. 

Since grain growth in the HPT-processed Ti starts at temperature 350 °C and higher [4], the investigation was focused on microstructure evolution after heating below this temperature. 

Figure 18.20 Schematic of the microstructure evolution with heating for the templated grain growth process. From Ref [49].

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