Study On Modeling Of Gradient-Porous Metal And The Fabrication Process By Selective Laser Sintering

Industrial waste gas have some characteristics of high temperature, a lot of smoke dust, tiny particles and harmful gases, which causes not only environmental pollution, but also harm our bodies, therefore, we must purify dust. Sintered porous metal filter can filter fine particles, which has some characteristics high temperature resistance, corrosion resistance, high porosity, high permeability, but gradient porous metal materials can satisfy filter requirements of high accuracy of the filter and the good permeability.However, it is the still in a preliminary stage in study on the gradient porous metals, especially in study on preparative technique of gradient porous metal materials. The thesis study on pore structure design of gradient porous metal materials and preparation of selective laser sintering process parameters infection on the properties of metals, which provided important scientific meaning and utility value for research of filtering quality of gradient porous metal materials in high temperature gas dust.Based on the UG, this thesis had designed the pore size, shape, position distribution and the internal pore structure of gradient porous metal materials, and had achieved the parametric design to use the UG secondary development language Open/GRIP, had developed GRIP procedure of gradient porous metal materials modeling,so as to realize the automatic modeling of gradient porous metal materials.This method greatly improves the design efficiency, shorten the design cycle, and reduce the cost.It is studied to molding character of316L stainless steel powder by selective laser sintering.The experimental results show:Single tracks channel experiment shows that is obtained to the continuous and stable single channel scan lines in the range of laser power80-98W, scanning speed70-120mm/s, P/V0.8-1.4; layer canning experiment shows that the overlap rate of tracks decreases with the increase of scanning interval under the same laser powder and scanning speed; block experiment shows that the density decreases and the porosity increase with the increase of the powder thickness,scanning interval and scanning speed under the same laser powder and scanning speed, the density in creases with the increase of the laser powder.It is studied to fabrication process of gradient porous metal by selective laser sintering. SLS fabrication technological parameter of gradient porous metal was optimized by orthogonal experiment, the optimum technics parameters were: laser power80W, scanning speed80mm/s, scanning path of skip turing, scanning distance0.05mm, powder thickness0.05mm, the porosity, the maximum pore diameter, the biggest permeability coefficient were15.62%,9.86μm,24.5m3/m2hKPa, the pore interconnection and the filtering performance is good, it can reach the purpose of purification to less than10microns particles in air. At same time, the technological parameter which influence surface microtopography and shape were studied in this thesis, the result show that the quality of part is good by the optimum technics parameter, such as smooth surface, appropriate aperture size, uniform pore-size distribution, small surface roughness, high porosity, bigger relative porosity.