【摘要】 本实验首次发现,在振动磨中混合粉磨PbO和TiO₂化学配比的粉体,能合成PbTiO₂化合物。这种机械力化学反应是以表面能为扩散的主要推动力,使PbO扩散至TiO₂颗粒内并在TiO₂颗粒表面形成PbTiO₂,实验证明在PbTiO₂形成以前,PbO及TiO₂二者受机械力的作用,晶型均已发生了变化,锐钛矿转变为金红石,铅黄转变为密陀僧。由铅黄向密陀僧转变的过程中,当密陀僧的容积成分达到75％时即达平衡状态,然而这种机械化学平衡是亚稳的,继续粉磨超过75h后,平衡即遭破坏,密陀僧又重新转变为铅黄。更多还原

【Abstract】 An this study, it is first found that the reaction of PbO+TiO₂→PbTiO₂ can take place during grinding PbO and TiO₂ mixed powders in stoichiometric proportions in vibration mill.It is considered that the surface energy is s major diffusive force making PbO diffuse into Ti₂ particles and forming PbTiO₂ on the TiO₂ particle surface.Experiments show that before forming PbTiO₂, the crystal phasea of both PbO and TiO₂ have been changed during grinding by the effect of mechano-cemical force, i. e., some anatase converts into rutile and massicot into litharge. The mechano-chemical equilibrium is reached when about 75% volume fraction of litharge are formed in the particles of massicot during grinding. However, this equilibrium is metastable, it will be broken when the mechanical force is exerted continuously up to 75h on the particles and the litharge converts back into massicot thereof.更多还原