泡沫金属发泡基础理论研究

【作者】 王茗；

【导师】 史庆南； 左孝青；

【作者基本信息】 昆明理工大学 ， 材料学， 2004， 硕士

【摘要】 多孔泡沫金属是近年来发展起来的一种结构-功能一体化的新型材料。其优异的性能和广泛的应用前景吸引了众多科技研究者的注意。但是对于发泡过程基础理论研究还不够全面，特别是气孔的发泡机制即气孔在基体金属内随外界条件变化而发生的形核、生长、运动和消亡等热、动力学条件的研究很少。 因此，论文在综述了泡沫金属发泡理论的最新研究成果的基础上，从微观机制出发，将发泡过程分为发泡剂分解、气体形核、气泡长大、合并、破裂等阶段，通过大量的热力学分析，得出了发泡过程中发泡剂分解以及气体的均匀形核和非均匀形核、气孔的生长和运动等热力学条件，揭示了气孔演化的趋势；论文根据内生气源发泡的特点，针对发泡过程各个阶段进行了动力学理论的研究，然后综合考虑各个阶段对最终孔结构和性能的影响，初步建立了泡沫金属发泡过程的动力学方程。该方程基本能从微观的角度预测最终气孔的平均半径，这对解决多孔泡沫金属制备中遇到的相关问题有一定指导意义。更多还原

【Abstract】 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.更多还原