在着火热自燃理论基础上,通过分析钛颗粒表面氧化膜与基体之间的应力状态,结合实验事实,提出氧化膜最外层首先发生破裂但不形成贯穿裂纹的观点,基于该观点建立模型理论研究外层氧化膜的破裂行为对钛颗粒着火过程的影响,并对钛的着火过程进行物理模拟实验研究.结果表明:在673 ～1373K范围,当环境温度较低时,钛颗粒发生恒温氧化,氧化膜破裂导致氧化动力学曲线由抛物线向直线转化,当处于高温时,氧化膜的破裂使着火温度降低45K,不会对钛颗粒的着火过程产生强烈影响;当钛颗粒尺寸增大时,钛颗粒的着火温度未出现明显升高,与铝颗粒着火过程氧化膜的完全破裂机制不同;氧化膜内应力的变化使由外而内的裂纹扩展到一定程度后停止,即外层氧化膜不完全破裂,从而加速氧在内层氧化膜内扩散,增大了钛颗粒发生着火的敏感性;非等温氧化实验间接验证了外层氧化膜非贯穿破裂对钛着火过程影响的理论研究.%Based on thermal self-ignition theory, in combination with theoretical analysis of the stress between oxide film and matrix with experiment fact, the viewpoint that outermost oxide film fractured first without penetrating crack was put forward, and based on this viewpoint, the model, studying the effect of outer oxide film fracture behavior on titanium particles ignition was established. Further, the physical analogue experiments about titanium ignition were carried out. Research results showed that in lower temperature during 673 -1373K, titanium particles oxidized thermostatically, and oxidation kinetics curve changed into straight line from parabola due to oxide film fracture. While in higher temperature, ignition temperature was reduced by 45K due to oxide film fracture, which had no obvious effect on ignition process of titanium particles. With increasing in size of titanium particle, there was no obvious change for ignition temperature of titanium particles, which was different from complete fracture of oxide film of aluminum particles. Change of stress in oxide film made crack extension stop after the crack extended to some extent, which accelerated oxygen diffusion in inner layer oxide film and increased ignition sensitivity of Litaniurn particles. Non-isothermal oxidation experiments proved the theoretical research on the effect of nonpenerative crack of outer layer oxide film on titanium ignition indirectly.
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