选区激光烧结用覆膜锆砂的制备及其SLS成形工艺研究

Preparation of Coated Zircon Sand Used for Selective Laser Sintering and Study on the Forming Process of SLS

采用冷、热法制备了覆膜锆砂,并进行了选区激光烧结成形工艺研究,着重探讨了单层扫描面积和激光功率对SLS覆膜锆砂砂型抗拉强度的影响。结果表明:在树脂含量相等条件下,相对于冷法,热法制备的覆膜锆砂的SLS成形砂型抗拉强度明显更高;单层扫描面积对覆膜锆砂砂型抗拉强度影响显著,随着扫描面积的增大,在同样烧结参数下,其成形初强度由0.27 MPa迅速下降到0.04 MPa;而激光功率是决定覆膜锆砂砂型抗拉强度的关键因素,115/170目覆膜锆砂粘结剂含量为2%的条件下,扫描面积约1 900 mm^2,合适的激光功率为35 W,成功制备覆膜锆砂砂型,并浇注出轮廓清晰、表面光亮的钛合金铸件。

The coated zircon sand was prepared by cold and hot method, and the forming technology of selective laser sintering of zircon coated sand was studied, and the influence of the single scanning area and the laser power of SLS on coated zircon sand tensile strength were discussed. The results show that with the same resin content, the tensile strength of the SLS formed by the hot method was higher than that of the cold method, the effect of single scanning area on the tensile strength of the coated zircon sand mold is significant, under the same sintering parameters, the initial strength decreased from 0.27 MPa to 0.04 MPa. The laser power is the key factor to determine the tensile strength of the coated zircon sand, binder content of 115/170 mesh coated zircon sand is 2%, the scan area is about 1 900 mm2, appropriate laser power is 35 W, the zircon coated sand molds were successfully prepared and the titanium castings with clear outline and bright surface were cast.