The theory of dimensions has been subject of considerable controversy and only in the last few decades has it been agreed that dimensional methods can serve as a powerful tool m experimental investigations of physical phenomena Its effectiveness becomes especially noticeable when the number of factors involved is large and the theoretical knowledge is insufficient However, like any other mathematical tool, the theory of dimensions can supply correct and useful results only if it is properly applied One example of improper application is the introduction of an exaggerated and sometimes simply of a nonexistent correlation between the experimental results The purpose of the present paper is to analyse these kinds of spurious correlation.
The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.
DIMENSIONAL ANALYSIS - SPURIOUS CORRELATION
