Fatigue and fracture behaviour of laser powder bed fusion stainless steel 316L: Influence of processing parameters

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:703

Article

Zhang, Meng^1,2  Sun, Chen-Nan³  Zhang, Xiang⁴  Goh, Phoi Chin²  Wei, Jun³  Hardacre, David²  Li, Hua¹ 

[1] Nanyang Technol Univ, Sch Mech & Aerosp Engn, Singapore Ctr Printing 3D, 50 Nanyang Ave, Singapore 639798, Singapore

[2] Lloyds Register Global Technol Ctr, 1 Fusionopolis Pl,09-11 Galaxis, Singapore 13852, Singapore

[3] Singapore Inst Mfg Technol, 73 Nanyang Dr, Singapore 637662, Singapore

[4] Coventry Univ, Fac Engn & Comp, Coventry CV1 5FB, W Midlands, England

关键词: Selective laser melting;    Laser powder bed fusion;    Stainless steel 316L;    Porosity;    Fatigue property;    Process window;   

DOI  :  10.1016/j.msea.2017.07.071

来源: Elsevier

【 摘 要 】

The laser powder bed fusion (L-PBF) process involves a large number of processing parameters. Extending the intricate relationship between processing and structure to mechanical performance is essential for structural L-PBF materials. The high cycle fatigue properties of L-PBF parts are very sensitive to process-induced porosities which promote premature failure through the crack initiation mechanisms. Results from this work show that for stainless steel 316 L, porosity does not impinge on the high cycle fatigue properties when processing is kept within a +/- 30% tolerance band. In this 'optimum' processing region, crack initiation takes place due to defects at the solidification microstructure level. Beyond the 'optimum' processing region, over-melting and under-melting can lead to porosity-driven cracking and inferior fatigue resistance. In addition, regardless of the processing condition, fatigue resistance was found to follow a direct linear relationship with ductility and tensile strength in the low and high stress fatigue regimes respectively.

【 授权许可】

Free