选区激光烧结聚醚醚酮成形缺陷及对力学性能的影响研究  

Forming Defects and Its Influence on Mechanical Properties of Polyetheretherketone Manufactured by Selective Laser Sintering

作　　者：刘禹 侯娟[1] Liu Yu;Hou Juan(School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学材料与化学学院,上海200093

出　　处：《中国激光》2023年第20期157-168,共12页Chinese Journal of Lasers

基　　金：国家自然科学基金(52073176);上海市自然科学基金(22ZR1443000)。

摘　　要：将选区激光烧结(SLS)技术应用于聚醚醚酮(PEEK)等高性能聚合物的制备,为严苛使用条件下复杂构件的制造提供了一种新的选择。研究了SLS制备PEEK材料的微观结构、成形缺陷与力学性能之间的关系。采用光学显微镜(OM)、扫描电子显微镜(SEM)和微计算机断层扫描(Micro-CT)对SLS制备的PEEK样品进行微观结构和成形缺陷的分析表征,包括结晶程度、孔隙、未熔合缺陷等。使用万能材料试验机进行室温力学性能测试,并与传统注塑(IM)样品对比。研究结果表明,SLS制备的PEEK样品具有较高的结晶度,其弹性模量和耐热性皆优于IM PEEK,但SLS PEEK样品的强度和塑性较IM PEEK低,拉伸强度为(86.5±3.3)MPa,弯曲强度为(161.9±23.7)MPa,断裂伸长率仅为(2.1±0.2)%。结合断口形貌观察和Micro-CT缺陷分析,对SLS制备过程中缺陷的形成机理及其对力学性能的影响作用进行了讨论,SLS成形过程中产生的层间大尺寸缺陷是导致强度较低和延展性较差的主要原因。Objective Selective laser sintering(SLS)is a promising technology in polymer additive manufacturing(AM).It enables the selective melting and solidification of powders using a laser based on computer-aided design(CAD)data and production of threedimensional prototypes or parts in a layer-by-layer sintering manner.SLS technology is increasingly used for the fabrication of complex structural components in many manufacturing areas owing to its short manufacturing cycle time,high geometric freedom,and possibility of low-cost customization.Polyetheretherketone(PEEK)is a semi-crystalline polymer with high-temperature resistance and excellent mechanical properties;therefore,researchers have been experimenting with its use in SLS technology to meet the demands of complex structural components designed to function in harsh environments.However,the high melting point and viscosity of polyetheretherketone cause significant equipment requirements;accordingly,only low-density parts can be manufactured using thismaterial.Recently,the developments in PEEK for SLS technology and high-temperature laser sintering equipment have solved thisproblem,allowing to produce reliable parts.The tendency to form defects in SLS-prepared parts is an inherent feature of thistechnology,which can have a negative impact on the mechanical properties of the produced part.Therefore,studying the relationshipbetween the porosity and processing parameters is a popular topic.Despite the importance of the mechanical properties of sinteredmaterials,one of the research gaps that remains to be investigated is the lack of quantitative characterization of defects in laser-sinteredPEEK.Accordingly,previous research has only focused on analyzing the microstructure of a small number of samples to improve theprocessing parameters.In this study,an attempt to address this issue is made by analyzing the microcomputed tomography(Micro-CT)results of sintered PEEK components.The main causes of defect formation during SLS forming are also explored,and the impacton the mech

关 键 词：激光技术 选区激光烧结 聚醚醚酮 缺陷 力学性能 微计算机断层扫描 

分 类 号：TQ326.5[化学工程—合成树脂塑料工业] TG665[金属学及工艺—金属切削加工及机床]