Effect Of Carbon Fibers Content On Microstructure And Properties Of Vacuum Counter-pressure Casting Aluminium Alloy By Selective Laser Sintering Resin Coated Sand Mold

Combining with Selective laser sintering(SLS) and vacuum Counter-pressure casting technology quickly casting no margin, complex thin-walled castings. Carbon fibers have been added to coated sand, improving SLS coated sand mold strength and thermal conductivity, has a great advantage in the formation of complex thin- walled parts in the field of aviation, aerospace and national defense. Study Effect of Carbon fibers content on microstructure and properties of Vacuum Counter-pressure casting aluminium alloy by selective laser sintering resin coated sand mold, for SLS coated sand mold vacuum Counter-pressure casting aluminum alloys lay a certain theoretical and technical support.In this paper, taking ZL205 A aluminum alloy as research object. By the different proportion of carbon fibers has been added into coated sand mold, using Vacuum Counter-pressure ZL205 A alloy casting ZL205 A, Study the influence of carbon fibers content on ZL205 A alloy density, microstructure, mechanical properties. The experiment results indicate that the influence of carbon fibers content on microstructure and properties of aluminum alloy is significant, When carbon fiber content of less than 3wt%, with increase of carbon fibers content,density increases, the microstructure refinement, tensile strength and elongation rate increase, when the carbon fibers content of more than 3wt%, with the increase of carbon fibers content, ZL205 A density decreases, microstructure coarsening, tensile strength and elongation decreased;. When carbon fibers content is the same, with wall thickness increase, higher the density, strength decreases, the grain size increases, microstructure morphology is basically the same, are equiaxed grain.The changing trend of density decrease first and the rose just like V shape from gate to top, near the gate, the density reach the peak, in addition, with increase of carbon fibers content,V-type gradual change significantly;When carbon fiber content is 3wt%, a wall thickness of 3mm, the minimum grain size is 38μm, the tensile strength and elongation reached the peak, were respectively 496.42 MPa 10.23%.Carbon fiber was added into SLS coated sand mold, the research obtain the influence law on microstructure and mechanical properties of complex thin-walled ZL205 A aluminum alloy castings castings by vacuum counter-pressure. It can provide SLS coated sand mold vacuum differential pressure forming aluminum a certain theoretical basis and practical application value.