文章信息/Info

Title:

Aging and Microstructure Evolution of Polyamide-12 during Selective Laser Sintering

文章編號:

16743962(2019)11105308

作者:

唐明晨1; 陳鵬1; 傅華1; 詹軍2; 佘勇2; 閆春澤1

（1�比A中科技大學(xué)材料科學(xué)與工程學(xué)院 材料成形及模具技術(shù)國家重點實驗室，湖北 武漢 430074）（2�焙�北三環(huán)智能科技有限公司，湖北 武漢 430074）

Author(s):

TANG Mingchen1;  CHEN Peng1;  FU Hua1;  ZHAN Jun2;  SHE Yong2;  YAN Chunze1

(1�盨tate Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China) (2�盚ubei Sanhuan Intelligent Technology Co., Ltd., Wuhan 430074, China)

關(guān)鍵詞:

增材制造; 激光選區(qū)燒結(jié); 尼龍12; 老化; 微觀結(jié)構(gòu)演變

Keywords:

additive manufacturing;  selective laser sintering;  PA12;  aging;  microstructure evolution

分類號:

TQ342+1；TG665

DOI:

10.7502/j.issn.1674-3962.201904009

文獻(xiàn)標(biāo)志碼:

A

摘要:

材料的老化是影響激光選區(qū)燒結(jié)（SLS）制件性能與精度的重要因素，其本質(zhì)原因與材料內(nèi)部的微觀結(jié)構(gòu)變化有重要關(guān)系。因此，著重探討尼龍12（PA12）的老化機(jī)制及經(jīng)過不同次SLS工藝處理后的粉末及其對應(yīng)制件的晶體結(jié)構(gòu)、元素化學(xué)狀態(tài)及性能變化。結(jié)果表明，老化的PA12粉末的XRD圖譜呈現(xiàn)類似Brill轉(zhuǎn)變的峰值合并現(xiàn)象，由此導(dǎo)致了老化粉末熔點的提高，且經(jīng)過3次重復(fù)利用的粉末的燒結(jié)窗口擴(kuò)大至31��00 ℃。X射線光電子能譜分析證實了固態(tài)和熔態(tài)縮聚反應(yīng)的存在，其使得老化粉末具有較高的成核溫度。差示掃描量熱實驗的結(jié)果表明，采用PA12老化粉末制備的制件出現(xiàn)了結(jié)晶延遲現(xiàn)象，而且隨著PA粉末老化程度的增加，固態(tài)縮聚使其結(jié)晶度不斷降低。

Abstract:

Materials aging is an important factor influencing the properties and surface accuracy of components fabricated by selective laser sintering (SLS) technology, the underlying cause is the microstructure changes of materials. Therefore, this work emphatically studied the mechanism of polyamide-12 (PA12) aging, and the changes of crystal structure, chemical states of elements and properties of the aged powders and the corresponded components after SLS process. The results show that the XRD patterns of the aged powders appear the peaks like Brill transition, resulting in the improvement of melting temperature of the aged powder. Moreover, the sintering window of the PA12 powder recycled for three times is expanded to 31��00 ℃. X�瞨ay photoelectron spectroscopy spectra demonstrates the presence of solid and melt state polycondensation, which results in higher nucleation temperatures of aged powders. Meanwhile, the crystallization delay phenomenon of components fabricated with aged powders is observed by differential scanning calorimetry. With the increase of aging level of PA12 powder, its crystallinity is generally reduced by solid state polycondensation.