An Evaluation Method Of Three-dimensional Grain Size Distribution In Polycrystalline Materials On The Base Of Emulation Slicing

The random linear intercept distribution of its three-dimensional size distribution can be obtained by the way of emulation slicing on its grain system. On the base of Mendelson's study, by which the three-dimensional size can be evaluated, the data of three-dimensional size distribution of equiaxed grain which is fitted to lognormal distribution and with the different value ofσandμis processed after partitioned into equal parts, then the random section is obtained by using emulation slicing, and then the random linear intercept length and its probability is calculated, from which the random linear intercept distribution is obtained, and then the data-base of size distribution is obtained as well. In practical application, through measuring the crystals random linear intercept of some material section, its random linear intercept distribution can be drawn, and through searching the data-base of size distribution, the matching random linear intercept distribution of actual measuring random linear intercept distribution and itsσandμof three-dimensional size distribution can be found, therefore the crystals three-dimensional size distribution of this material is obtained.Results show that three-dimensional size distribution of equiaxed grain which is fitted to lognormal distribution and with the different value ofσandμ, becomes more stable as the slicing number n increases. When n became some value, the shape, peak value and velvet of the random linear intercept distribution did not obviously change. That is because as the number of tetrakaidecahedron(the slicing number n) with different volume is big enough, the range of its random linear intercept and the sum of its random linear intercept probability which belonged to the different h, became some constant, so the random linear intercept distribution of whole grain system that obtained by pulsing the random linear intercept distribution of tetrakaidecahedron with different volume, became stable as well. This also proves that the relationship between three-dimensional size distribution of equiaxed grain and its random linear intercept distribution is correlative, and basing on this a new way , the three-dimensional size distribution of polycrystalline is obtained.For the data-base of size distribution which is established on the curve drawing and peak value calculation of three-dimensional size distribution of equiaxed grain and its random linear intercept distribution, the precision ofτ,μand h can directly influence the precision of calculating the practical polycrystalline's three-dimensional size distribution. Considering the quantity of practical calculated grain sections, the value of h should be adjusted to get the smooth practical random linear intercept distribution, so the error which caused by unsmooth distribution can be reduced when checking the data-base of size distribution.Through measuring the practical polycrystalline material, its grain three-dimensional size distribution can be obtained, and feasibility of this new measurement in this paper is also proved.