Metal Foam Foam In Basic Theoretical Research

Porous metal is a new structural and functional composite material developed in recent years. Its excellent properties and applied prospects have drawn attention of technologists. But the basic theories producing porous metals in high temperature were not yet fully understood, especially the foaming mechanism, foaming thermo-dynamics study on nucleation, growth, movement and rupture of gas bubble were rarely researched.This paper narrate the latest progress in the foaming theory of metal foams. Acording to the micromechanism, the foaming process consist of decomposition of the foaming agent TiH2, homogeneous and heterogeneous bubble nucleation, bubble growth, bubble merge and rupture. The thermodynamic analysis of decomposition of the foaming agent TiH2, homogeneous and heterogeneous nucleation in high-temperature, growth and movement were achieved to demonstrate the trend of pore evolvement in this paper. Moreover, according to the characteristics of in-situ gas foaming, every stage of foaming kinetics was studied, then comprehensive considering the influence of every stage to the pore structure and property ,we established the foaming kinetics equation of metal foams.From the microscopic view ,the equation can forecast the mean radius of the final pore ,it help to solve some problem in the production.