Sintering anisotropy of binder jetted 316L stainless steel: part II – microstructure evolution during sintering

IF 1.9 4区材料科学 Q2 METALLURGY & METALLURGICAL ENGINEERING

Powder Metallurgy Pub Date : 2022-01-03 DOI:10.1080/00325899.2021.2020486

Alberto Cabo Rios, E. Hryha, E. Olevsky, P. Harlin

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引用次数: 8

Abstract

ABSTRACT Green density of binder jetted parts are typically equal or lower than the powder tap density. Also, anisotropic green porosity distribution is expected because of the characteristics of the binder jetting (BJ) printing process. In this study, the microstructure evolution in terms of phases and porosity characteristics was studied. A transition from irregular-shape interconnected porosity in pre-sintered samples to closed quasi-spherical porosity for samples sintered at 1370°C was observed. EBSD phase map showed ∼2.73% of δ-ferrite in sample sintered at 1370°C. The anisotropic porosity distribution was revealed by a higher area fraction of aligned large pores (>35 µm), within the cross-section perpendicular to the building direction. Chemical analysis showed an increase of C, O and N on the green sample, while a strong decrease was found after sintering when compared with the powder chemistry. δ-ferrite onset, from phase equilibrium calculations, varies from ∼1250°C (sintered sample chemistry) to ∼1350°C (powder chemistry).

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粘结剂喷射316L不锈钢的烧结各向异性：第二部分——烧结过程中的微观结构演变

粘结剂喷射零件的生坯密度通常等于或低于粉末振实密度。此外，由于粘结剂喷射（BJ）印刷工艺的特性，预计会出现各向异性的生坯孔隙率分布。在本研究中，研究了微观结构在相和孔隙率特征方面的演变。观察到预烧结样品中的不规则形状互连孔隙向1370°C烧结样品的闭合准球形孔隙的转变。EBSD相位图显示，在1370°C下烧结的样品中，约2.73%的δ-铁氧体。各向异性孔隙率分布通过排列的大孔隙的较高面积分数（>35 µm），在垂直于建筑方向的横截面内。化学分析显示，与粉末化学相比，生坯样品上的C、O和N增加，而烧结后发现显著降低。根据相平衡计算，δ-铁素体的起始温度从～1250°C（烧结样品化学）到～1350°C（粉末化学）不等。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Powder Metallurgy 工程技术-冶金工程

CiteScore

2.90

自引率

7.10%

发文量

审稿时长

3 months

期刊介绍： Powder Metallurgy is an international journal publishing peer-reviewed original research on the science and practice of powder metallurgy and particulate technology. Coverage includes metallic particulate materials, PM tool materials, hard materials, composites, and novel powder based materials.