Study On Selective Laser Sintering Of Aumina Parts And Post Pocess

Selective laser sintering (SLS) is a kind of mature rapid prototyping (RP). At present it is a hot issue and difficult problem that SLS is applied to manufacture complex functional moulds and alumina parts rapidly, which has wide application in mechanical industry. But based on the worldwide research, there are some problems in manufacturing alumina parts by SLS, such as incomplete process, low strength and unable to satisfy commercial need. The purpose of this paper is focus on indirect selective laser sintering alumina parts and its post processing technology. The main research contents and results are as follows:Epoxy resin E-06 and alumina powder with the granularity 80-100um are averagely mixed as SLS material which is very easy to produce with low cost and good forming property. The proportion of the binder and the preparation methods are also determined.The mechanism of laser sintering for SLS material has been discussed. The effect of sintering parameters on strength and accuracy of green part is analysed theoretically. Sintering parameters which include laser power, scanning speed, scanning space and layer thickness are optimized as follows: P=14w, v=2000mm/s, d=0.1mm, h=0.1mm.Post-processing of green part has been investigated too. A series of method is summarized for removing powder. Infiltrator and infiltration process are determined by the selection principles and infiltration efforts. Debinding temperature, keeping time and protection atmosphere are analysed for removal of binder. High temperature sintering study focus on mechanism and process of sintering, effect of sintering parameter on property of sinter. The quality and performance of alumina pars are researched by the measurement of bending strength and density, the phase and microstructure are also analyzed by XRD,SEM. The bending strength of alumina parts is 32.62MPa and the density is 2.12g/cm~3 which can satisfy the use requirement of complex functional moulds.Improving strength of alumina parts by SLS has been researched. The brittleness root of alumina is analyzed from crystal structure. Improving methods are put forward. Based on the improving mechanism of additives, influence on strength and quality of alumina parts are investigated by inducing composite additive. The results show that bending strength can up to 58.65MPa and the density is 2.82g/cm~3 which have better improving effect and satisfy the rapid manufacture of complex alumina parts.Therefore, based on the study of indirect selective laser sintering alumina parts and post process, complex functional moulds and alumina parts can be manufactured through this method successfully, which is very meaningful for widening application area and commercialization in ceramics.