纳米粒子堆垛模型及其热喷涂传热数值分析

Stacking model of nano-particles and heat transfer numerical analysis under thermal spraying conditions

将纳米粒子团聚大颗粒进行抽象处理,提出以理想堆垛结构为假设的纳米团聚颗粒模型。以ANSYS有限元软件为平台,模拟Al2O3-13%TiO2(质量分数)团聚纳米颗粒在热喷涂环境下的传热过程,分析传热时间、团聚颗粒直径和孔隙率等对传热的影响,并分析团聚颗粒在热喷涂传热后的组织结构差异。结果表明:在一定传热条件下,纳米团聚颗粒可以保持部分纳米粒子或长大为亚微米晶形态,且团聚颗粒直径越大,这类组织就越容易形成,而团聚颗粒孔隙率在0.48以下时,对组织形态的影响较弱。

According to the agglomerated structure of nano-particles,a novel assumption structure model based on ideal stacking structure was proposed.The temperature field of agglomerated structure Al2O3-13%TiO2（mass fraction） particle under thermal spraying conditions was simulated by using the finite element analysis tool of ANSYS.The influence of heat transfer time,agglomerated particle diameter and porosity were separately analyzed.The differences in microstructure were also experimentally analyzed after heat transfer in the thermal spraying.The results confirm that,under certain heat transfer conditions,the agglomerated nano-particles can be partially maintained or grow into sub-micron crystal.And the larger the diameter of agglomerated particle is,the easier the formation of such organization is.In addition,the influence of the porosity becomes weak when it is below 0.48.