应用于选择性激光烧结的结晶性高分子材料粉末的工艺评述

从3个方面对结晶性高分子材料粉末在选择性激光烧结(SLS)的工艺进行评述,分别为高分子材料粉末的制备工艺、高分子材料粉末的复合改性工艺和高分子材料粉末的SLS工艺。其中在高分子材料粉末的制备工艺中对高分子材料粉末的制备方法和基本要求,以及高分子材料粉末在SLS工艺中的性能表征及使用的仪器设备等进行了介绍;在高分子材料粉末复合工艺中对复合改性方法和改性目的进行了叙述;在高分子材料粉末的SLS工艺中对影响成型件精度的各种参数进行了阐述。     

PS粉末激光烧结快速成型技术及其在铸造中的应用

系统地阐述快速成型技术的工艺方法、常用成型材料及选择性激光烧结技术的原理,介绍聚苯乙烯（PS）粉末的特性及成型工艺参数。指出对PS粉末烧结成型件进行不同的后处理,可将其作为原型件、功能件或精铸模具使用。最后论述了PS粉末选择性激光烧结技术在铸造领域的广泛应用,     

SLS高分子粉末材料的成型工艺参数及质量的比较研究

介绍了选用PS基3种高分子粉末材料,在AFS-320快速成型机上采用正交试验法研究预热温度、激光功率、分层厚度、扫描速度等工艺参数对可烧结性能和烧结件质量的影响,获得了各材料的优化烧结工艺参数。并测试试样拉伸强度,比较了3种粉体的工艺性能、成型质量、优缺点和用途范围,可为合理选用SLS高分子粉末材料提供参考依据。     

基于快速制造新型注塑模具设计的探讨

重点针对快速原型制造技术中的新型塑料水龙头注塑模具结构、冷却系统、浇注系统的位置与尺寸进行了设计，阐述了产品创新开发中的快速原型(RP)技术与CAD／CAE／CAM之间的关系。并就简化模具结构设计的优缺点与前后三次激光选区烧结（SLS)的成型工艺条件和收缩率进行了探讨，提出了SLS技术的现状、发展趋势与方向。     

碳纤维填充聚酰胺基本材料

位于意大利摩德纳的CRP技术公司是一家快速制造机器原型的树脂系统制造商,近来宣布开发出一种品名为WindfromXT2．0的碳纤维填充聚酰胺的基体材料。该材料可选用激光烧结（SLS）而设计的产品,而且表示众所周知的WindfromXT产品线,     

选择性激光烧结用聚合物粉末材料的研究进展

选择性激光烧结是一种增材制造快速成型技术。原材料的结构、组成和特性对激光烧结件的质量起着关键性的作用。聚合物粉末是激光烧结技术中应用最早、最广泛的一类材料。该文重点介绍了多种结晶与非结晶聚合物粉末及其复合材料在SLS中的研究现状和发展,并对其材料的应用前景进行了展望。     

选择性激光烧结用聚合物粉末材料研究进展

选择性激光烧结(SLS)是一项重要的3D打印技术，目前已广泛应用于各个高新技术领域。本文首先介绍了三种聚合物粉末的制备方法及原理，主要包括机械粉碎法、溶剂沉淀法和相分离法，并分析总结了三种制备方法的优缺点。其次，重点论述了聚合物粉末特性对SLS工艺的影响，如粉末材料的粒径大小、表面形貌以及材料的表面张力。最后，分析总结了SLS工艺参数对烧结制件性能的影响因素。本文的研究内容可为从事聚合物粉末SLS技术的相关生产技术人员和科研人员提供参考借鉴。     

选区激光烧结聚丙烯试件翘曲变形研究

选区激光烧结(SLS)是快速成形技术的重要分支,其原料选取范围广.结晶性聚合物在SLS成形过程中存在较大的收缩变形,工艺较难控制,但此类材料韧性和强度很好,因此其SLS制造有巨大的发展潜力.利用HRPS-ⅢA快速成形系统,进行选区激光烧结聚丙烯粉末材料的实验探索,研究了主要工艺参数对样件翘曲变形的影响.结果显示,样件的翘曲变形随激光功率加大而增大;铺粉厚度从0.15mm逐渐增大时,样件翘曲变形随之增大;随扫描速度的变化,样件翘曲量存在极小值.选取激光功率为12.5W,扫描速度为1800mm/s,铺粉厚度为0.15mm的工艺参数组合,成形聚丙烯样件的翘曲量为0.22mm.采用补偿系数方法制备的拉伸试样,其实际尺寸接近设计值.     

鑫达集团聚酰胺3D打印粉末耗材研发成功

正近日,鑫达集团研发团队成功完成了选择性激光烧结(SLS)聚酰胺粉末耗材的中试实验,以及材料的适配性验证。至此,鑫达集团聚酰胺3D打印粉末耗材研发项目取得了圆满成功,为鑫达集团3D打印耗材家族再添一名新成员。选择性激光烧结粉末耗材主要包括金属粉末耗材、覆膜砂粉末耗材、陶瓷粉末耗材以及高分子粉末耗材等一系列产品。其中占据市场主流的是高分子粉末耗材,主要有聚酰胺、聚丙烯、聚苯乙烯粉末耗材等。聚酰胺类材料中的聚酰胺12因其原材料优异的性能非常     

选择性激光烧结聚丙烯工艺-结构-性能的研究

系统地评价了商用选择性激光烧结（SLS）聚丙烯（PP）的加工性能和力学性能，并比较了它和注射成型（IM）样品的差异。结果表明，预热温度、激光功率和能量密度作为选择性激光烧结的3个重要工艺参数，对最终产品的性能有很大影响。在选择工艺参数时，必须同时兼顾制品的力学性能和尺寸精度。本文的独特之处在于定量分析了不同工艺条件下选择性烧结带的结晶形态，建立了工艺条件、结晶晶型和力学性能之间的关系。通过调整选择性激光烧结的工艺参数，可获得不同晶型含量的样品，以便调控制品的力学性能。     

聚合物选择激光烧结成型的研究进展

选择激光烧结是一种新型的快速成型技术。简要论述了选择激光烧结成型原理、研究现状、聚合物成型原料的选择、影响因素、发展前景等。     

用于选择性激光烧结功能件的基体聚合物烧结材料的研究

选取PC、ABS和HIPS三种典型的无定形聚合物粉末材料作为基体聚合物烧结材料，对其烧结及后处理性能进行了研究。经比较，有较好后处理效果的PC和有较好原始力学性能的HIPS均可作为新材料的基体聚合物烧结材料。并提出了进一步提高烧结功能件力学性能的方法，对今后用于制作功能件的SLS粉末材料的开发具有指导意义。     

尼龙6的选择性激光烧结成型工艺实验研究

使用尼龙6(PA6)粉末材料进行选择性激光烧结(SLS)成型实验,以成型件的成型精度和表面粗糙度作为衡量指标,通过控制变量法、正交试验以及极差分析研究了预热温度、激光功率和扫描速度对其成型质量的影响。结果表明,PA6粉末材料SLS成型件的X向和Y向尺寸精度以及侧面表面粗糙度并不会明显受到相关工艺参数的影响,其均存在于-1.26%^-0.99%和-1.96%^-1.29%以及16.91~19.87μm范围内;以成型件的成型精度和上表面粗糙度作为衡量指标,PA6粉末材料SLS成型的最优工艺参数组合为:预热温度115℃,激光功率35 W和扫描速度1800 mm/s;在最优条件下进行烧结验证实验,得出成型件的X向、Y向和Z向的成型尺寸精度分别为-1.13%、-1.48%和0.75%;上表面及侧面的粗糙度分别为14.6和18.55μm。     

High-performance ceramic parts with complex shape prepared by selective laser sintering: a review

ABSTRACT

Selective laser sintering (SLS) is an additive manufacturing technology which has shown great advantages in direct formation of the polymer, metal and their composites. However, ceramic parts prepared by the SLS still exhibit some fatal defects, including low density and poor mechanical properties. In this respect, recent advances for preparing ceramics have improved the final density and performance by adopting post-processing methods. In this review, three commonly used powder preparation approaches (i.e. mechanical mixing, solvent evaporation and dissolution-precipitation process) and two powder sintering mechanisms for the SLS are introduced. Porous ceramic parts are prepared directly through the SLS by virtue of their high porosity. And dense, high-performance Al₂O₃, ZrO₂, kaolin and SiC ceramic parts with complex shape are prepared by introducing CIP technology into the SLS, indicating that the hybrid technology could be the promising route for preparing high-performance ceramic parts used in various fields.     

选择性激光烧结用聚合物基材料制备研究进展

选择性激光烧结（selective laser sintering, SLS）是一种重要的3D打印加工技术,可制备传统加工无法制备的任意复杂形状的制件,广泛应用于航空航天、国防装备、医疗器械以及汽车等高新技术领域。本文介绍了SLS技术的加工原理和优势,综述了SLS技术加工成形用材料种类及聚合物基粉体材料的制备方法,主要包括相分离法、机械粉碎法、溶液法和喷雾干燥法。重点对SLS技术制备聚合物基压电复合材料及制品的国内外研究现状进行总结。虽然SLS打印制造技术面临聚合物原料种类少、功能缺乏、粉体生产成本高以及难以批量制备等瓶颈问题,但经过不断地创新与发展,SLS打印技术将成为高性能多功能高分子复合材料及其大型复杂制件的极佳制造方法。     

聚碳酸酯粉末的选择性激光烧结成型

以聚碳酸酯(PC)粉末为烧结材料,研究了激光功率等工艺参数对PC烧结件的微观形态、密度和力学性能的影响规律。结果表明,PC烧结件的密度、拉伸强度及拉伸弹性模量、冲击强度均随激光功率增加而增大;但过高的激光功率会导致激光扫描区域的粉末过热,使PC烧结件产生颜色变黄、轮廓不清晰等缺陷。     

Research on selective laser sintering of Kaolin–epoxy resin ceramic powders combined with cold isostatic pressing and sintering

In order to fabricate traditional products with complex shapes consisting of Kaolin ceramic, selective laser sintering (SLS) combined with cold isostatic pressing (CIP) process was used to consolidate Kaolin powder with additive of epoxy resin E06. To begin preparing the material, epoxy resin (10 wt%) and Kaolin were combined through mechanical mixing, which provided a good fluidity for SLS. Investigations on the shrinkage and micro topography of Kaolin–epoxy resin SLS samples were conducted to optimize the laser sintering parameters. It was found that SLS samples represented acceptable shrinkage and high density when laser energy density was 0.3300–0.3763 J/mm². Then the SLS samples were processed by CIP to eliminate the pores in green ceramics. Finally, the optimized SLS/CIP Kaolin samples were debinded and sintered to produce crack-free Kaolin ceramics. The “Yellow Duck” Kaolin ceramic product was fabricated by combining SLS/CIP with colored glazing. The study shows a novel and promising approach to fabricate complex traditional ceramic products via SLS combined with CIP and sintering.     

Preparation and indirect selective laser sintering of alumina/PA microspheres

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.