The Preparation Of Composite Wax Powder And Its Study On The Technology Of Selective Laser Sintering

There are many shortcomings for precision casting wax powder, such as shrinkage oflarge, serious warp deformation and the immature molding process. These shortcomingsseriously affect their promotion. The purpose of this paper is prepared composite-waxpowder material. The material is suitable for selective laser sintering. The wax castingpowder selective laser burn technology is currently research hotspot in the world, it is notonly the product with high precision and surface is smooth.According to the requirement of the sintering of powder and the characteristics ofmaterial itself performance, the preparation process of composite-wax powder is studied.The composite-wax powder is modified by orthogonal. The optimum component ofcomposite-wax powder include that wax mixture is98.8%, antistatic agent is0.05%, rayabsorbent is0.3%, surfactant is0.7%. The capability of powder include that mean particlesize is30μm, absorbent is0.059%, vicat softening point is65℃, ash is0.32%, packeddensity is0.15g·cm-3and melt index is5.2g·10min-1.The technical parameters of sintering Composite-wax powder were optimized on thebases of experiments, with the dimension precision and the sintered density being guideline.The best processing parameters is got by the using of square error analysis method. Thesintering parameters include that power is16W, scanning speed is1400mm·s-1, powerbed depth is0.15mm and preheating temperature is60℃.The major effect factors on part’s precision are analyzed. Shrinkage of large andserious warp deformation during SLS are discussed. Composition of shrinkage, themechanisms of shrinkage and the relationshs between shrinkage and parameters arediscussed. After the fundamental reason and developing trend of warp deformation areillustrated, its solving measurements are proposed. The sample of wax powder is used to make immersion test. Experimental results showthat the precision of the SLS post-processing of mechanical properties and got obviousimprovement. Through the microscope scanning for sintering section microscopicanalyses from the organization and post-treatment, finished product after that few innumber, pore size is small, compactions density.