The application of grey theory to the diffusion phenomenon

In the material research we often investigate the mass transport phenomenon. As is known the mass in metals are transferred by diffusion movement. Most of the physical and chemical process is related with the diffusion phenomenon. It is the most important subject for the material science which we call it diffusion theory. Now we usually adopt the experimental method to research the diffusion in the material. But the diffusion velocity of atom in the metal is very slow and it takes us much time to observe it. What´ more the movement usually can not observe directly and we should take many methods to help the researcher to observe it. The grey theory is an effective method to investigate the poor information and can be used to find the data law on the basis of a few known data. It has been extended into many fields. In the paper the authors firstly introduce the grey theory into the material research. Using the step-by-step optimum model GM (1, 1) the authors investigate the law in the diffusion phenomenon. Two examples show the fitting data and predictive result are good. It is a new way for the material scholars to do the research and is deserved to extend to other fields. The model is fit for equal and unequal interval which means it can be easily used in many conditions.