The purpose of this paper is to develop a novel two‐laser beam stereolithography system which has the advantages of low cost, fabrication time reduction and high accuracy.
The wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of the visible‐light curable resin (NAF202) used. The blue light laser is suitable for scanning the contour of objects because of its fast absorbance, thus giving a narrow cured depth. The green light laser is better suited to scanning the internal crosshatch to condense the fabrication time because of its deep penetration and its high power results in a wide cured width. A photoabsorber, carbon powder with an average diameter of 0.1 μm, is adopted to control the cured layer thickness. An adaptive crosshatch technique is introduced and applied to the fabrication process. Two benchmarks are proposed and fabricated using the developed system to evaluate the fabrication capability. Furthermore, a coordinate measuring machine is employed to evaluate the accuracy of the fabricated benchmark parts.
An optimal weight percentage of 1.5 is specified. The technique developed in this study is feasible for the fabrication of highly‐convoluted objects such as fan blades. The inclusion of the adaptive crosshatch technique in the developed system significantly reduces the fabrication time.
The results presented in this paper show that the developed system can fabricate objects quickly with high accuracy.
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