Kinetics of the early-stage gas porosity development caused by bubble coalescence

As a function of time bubble size distributions are calculated taking into account nonideal gas behaviour in small bubbles and the dependence of the surface diffusion coefficient on surface curvature. Comparison with available experimental results at the early stages of bubble development in uranium dioxide and aluminium reveals a better agreement with the calculations carried out, assuming that the motion of small bubbles in uranium dioxide is caused by surface diffusion and in aluminium by volume diffusion. [Russian Text Ignored]