Preparation and indirect selective laser sintering of alumina/PA microspheres
Preparation and indirect selective laser sintering of alumina/PA microspheres
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DOI：
10.1016/j.ceramint.2011.08.055
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发表时间：
2012-03-01
影响因子：
5.2
通讯作者：
Vleugels, Jef
中科院分区：
文献类型：
--
作者：
Shahzad, Khuram;Deckers, Jan;Vleugels, Jef
间接选择性激光烧结（SLS）是一种很有前途的增材制造技术，可以在两步工艺中生产具有复杂形状的陶瓷零件。在第一步中，沉积的聚合物/氧化铝复合微球层中的聚合物相通过扫描激光束局部熔融，导致局部陶瓷颗粒结合。在第二步中，通过缓慢加热从绿色部件中除去粘合剂，随后炉烧结以增加密度。在这项工作中，聚酰胺12和亚微米尺寸的氧化铝。采用一种新型的相转化技术制备了均匀的球形复合粉体。复合粉末具有良好的流动性和成型性。采用差示扫描量热法（DSC）测定了复合粉末的热性能和激光加工窗口。研究了激光功率、扫描速度和扫描间距等激光扫描参数对绿色零件成形的影响。随后将绿色部件脱粘并在炉中烧结以生产无裂纹的氧化铝部件。然而，部件的烧结密度仅限于理论密度的50%，因为在微球沉积期间形成的球间空间和烧结后的SLS。(C)2011 Elsevier Ltd和Techna Group S.r.l. All rights reserved.
Indirect selective laser sintering (SLS) is a promising additive manufacturing technique to produce ceramic parts with complex shapes in a two-step process. In the first step, the polymer phase in a deposited polymer/alumina composite microsphere layer is locally molten by a scanning laser beam, resulting in local ceramic particle bonding. In the second step, the binder is removed from the green parts by slowly heating and subsequently furnace sintered to increase the density. In this work, polyamide 12 and submicrometer sized alumina were used. Homogeneous spherical composite powders in the form of microspheres were prepared by a novel phase inversion technique. The composite powder showed good flowability and formability. Differential scanning calorimetry (DSC) was used to determine the thermal properties and laser processing window of the composite powder. The effect of the laser beam scanning parameters such as laser power, scan speed and scan spacing on the fabrication of green parts was assessed. Green parts were subsequently debinded and furnace sintered to produce crack-free alumina components. The sintered density of the parts however was limited to only 50% of the theoretical density since the intersphere space formed during microsphere deposition and SLS remained after sintering. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.