Study On Dynamics And Process Of Fe-based Porous Materials By Transient Liquid Phase Sintering

As functional and structural materials with excellent properties, porous metal materials are widely used in many occasions such as filtration, separation, gas transport, catalyst carrier and etc. because of their unique advantages like light weight, high specific surface area, easy shaping and etc..In this article, Fe-based porous material was prepared by transient liquid phase sintering. The kinetics of sintering process and process parameters were studied.The author studied the solid-state diffusion of the sintering system by means of DSC thermal analysis and found that obvious solid diffusion occured between Fe and Ni-P powders, and the size of Ni-P powder played a decisive role in the solid diffusion rate.Solid diffusion can increase total liquid amount while the size of Fe and Ni-P powder has no significant impact on it. Solid diffusion model was also established to predict the pattern in which Fe particle size, Ni-P particle size and heating rate effected diffusion of elements.By the means of SEM surface analysis, XRD-ray diffraction analysis and spectrum analysis, morphology, phase composition and element distribution evolution in isothermal solidification process were studied. Fe has a faster dissolution-diffusion rate in the liquid phase sintering. P has a high homogenization speed in solid and liquid area, but for a long holding time P will segregate in the local area as a new phase (FeNi) 3P.Holding time has no obvious impact on the most probable pore diameter and porosity, but can significantly increase uniformity of pore size distribution in porous materials. A reliable diffusion model of transient liquid phase sintering was established, and can help set an effective theory basis for establishment of sintering process.Orthogonal experiment results show the order of parameters which effect porosity and compressive strength respectively is alloy powder content> Fe powder particle size> sintering temperature> alloy powder particle size and sintering temperature> alloy powder content> alloy powder particle size> Fe powder particle size.On the basis of a comprehensive representation of Fe-based powder transient liquid phase sintering process, the paper provides a theory base on controllable preparation of porous materials through selection of process parameter, and possesses a great practical value.