Optimization of Selective Laser Melting Process Parameters Via Taguchi's Methods and Gray Relational Analysis for 3D Printing of 18Ni‐300 Maraging Steel. Issue 5 (30th November 2022)

• Record Type: Journal Article
• Authors: Law, Wee King; Wu, Ziyang; Song, Chenghao; Wang, Haoliang; Wong, Kok-Cheong; Lim, Chin Seong; Sun, Zhenzhong
• Is Part Of: Steel research international. Volume 94:Issue 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-30
• Subjects: additive manufacturing -- digital image correlation -- gray relational analysis -- maraging steels -- Taguchi methods; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.202200203
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract : Taguchi methods and gray relational analysis are used to determine optimal processing conditions for the selective laser melting (SLM) of 18Ni‐300 maraging steel. The following SLM process parameters are selected for optimization: laser power ( P ), scanning speed ( v ), and hatch spacing ( h ). Statistical analysis indicates that SLM parameter configuration no. 5 (275 W, 700 mm s −1, 0.08 mm) as most suitable for the simultaneous improvement of tensile strength, elongation (or ductility), hardness, and impact toughness. The order of influence of SLM parameters is identified as follows: P ≈ v > h . Samples with improved mechanical properties can be produced using configurations with higher linear energy density ( E L ). This is because the increased laser energy input facilitates complete melting of metal powder, as well as better interlayer bonding between melt pools. Higher E L can be achieved by either increasing P or decreasing v . Digital image correlation analysis indicates that tensile test samples with higher porosity exhibit lower ductility due to its inability to accommodate plastic strain accumulation for prolonged durations. Fractography analysis indicates that during tensile loading, cracks will nucleate around the pore perimeter and propagate via microvoid coalescence. Fracture will occur at regions with higher porosity due to it having multiple crack initiation sites. Abstract : Statistical analysis indicates that configuration no. 5 (275 W, 700 mm s −1, 0.08 mm) is the most optimal. The order of influence of selective laser melting parameters is determined as P ≈ v > h . Digital image correlation and fractography analyses indicate that regions with higher porosity exhibit high strain accumulation during tensile loading, resulting in an earlier fracture at that region.