Article Details

Abstract

As heterogeneous metal composites are increasingly adopted in integrated structural–functional applications, controlling porosity and improving interfacial quality during SLM fabrication has become essential for ensuring material performance. In this study, based on Selective Laser Melting (SLM), the effects of gradient layer thickness on the porosity distribution and interfacial microstructure of CuSn10–316L stainless steel composites were systematically investigated. Several linear gradient deposition schemes are fabricated to clarify how layer thickness variation influences densification behavior, pore evolution, and structural features within the fusion zone. The results indicate that thinner layers help stabilize the melt pool, significantly reducing porosity and enhancing interfacial bonding, whereas thicker layers are more susceptible to differences in melting characteristics between the two alloys, leading to increased porosity and interfacial defects. Microstructural observations further demonstrate that gradient structuring modifies the transition-zone morphology and the pattern of microcrack distribution. These findings highlight the critical role of gradient layer thickness in controlling the forming quality of SLM-fabricated composites and provide valuable insight for optimizing the design and processing of multi-material gradient structures.

Keywords

selective laser melting; gradient layer thickness; composite material; porosity

References

1. [1] Bian Yuchao, Peng Yingbo, Song Lingfeng, etc Research on Laser Selective Melting of 316L/IN718 Heterogeneity Based on Laser Remelting Optimization Process [J]. China Laser, 2021, 48 (18): 80-91
2. [2] PANDEY V，SEETHARAM R，CHELLADURAI H. A Comprehensive Review: Discussed the Effect of High-entropy Alloys as Reinforcement on Metal Matrix Composite Properties, Fabrication Techniques, and Applications [J/OL].Journal of Alloys and Compounds，2024：175095[2025-11-03].https://doi.org/10.1016/j.jallcom.2024.175095.
3. [3] He Xin, Luo Xia, Tang Jingang, etc Microstructure evolution and crack generation mechanism of CuSn10/AlSi10Mg functionally graded materials prepared by laser selective melting [J]. China Laser, 2024, 51 (20): 220-231
4. [4] Gao Ruize, Wang Yaqiang, Zhang Jinyu, etc Research progress on preparation methods and mechanical properties of gradient structured metal materials [J]. Materials Review, 2024, 38 (15): 17-28
5. [5] HASANOV S，ALKUNTE S，MITHILA R，et al. Review on Additive Manufacturing of Multi-Material Parts: Progress and Challenges [J].Journal of Manufacturing and Materials Processing，2021，6（1）：4.
6. [6] Li Xueyong, Jiang Wei, Zhai Haifeng, etc Study on fatigue crack propagation behavior of 316L stainless steel specimens melted by selective laser [J]. Mechanical Design and Manufacturing Engineering, 2025, 54 (10): 1-6
7. [7] Zhang Xuanming, Sun Kun, Zhang Liang, etc Laser selective melting and interface control of β - calcium phosphate enhanced zinc alloy [J]. Journal of Xi'an Jiaotong University, 2025, 59 (6): 73-81
8. [8] Han Yusheng, Yang Jianjun, Zheng Ying, et al. Interface structure design of 3D printed flexible stretchable discrete functional gradient substrates [J]. China Plastics, 2025, 39 (9): 68-74
9. [9] CADMAN J E，ZHOU S W，CHEN Y H，et al. On Design of Multi-functional Microstructural Materials [J].Journal of Materials Science，2013，48（1）：51-66.
10. [10] GUO S，LI Y N，GU J R，et al. Microstructure and Mechanical Properties of Ti6Al4V/ B4C Titanium Matrix Composite Fabricated by Selective Laser Melting (SLM) [J].Journal of Materials Research and Technology，2023，23：1934-1946.
11. [11] Chen Hui, Dong Jing, Zi Xuhui, etc Comparative study on microstructure and defects of SLM and SEBM formed pure tungsten [J]. Rare Metal Materials and Engineering, 2022, 51 (9): 3282-3288
12. [12] YUAN X J，CHEN M J，YAO Y，et al. Recent Progress in the Design And Fabrication of Multifunctional Structures Based on Metamaterials [J/OL].Current Opinion in Solid State & Materials Science，2021，25（1）：100883[2025-10-28].https://doi.org/10.1016/j.cossms.2020.100883.
13. [13]Ferreira A D B L， Nóvoa P R O， Marques A T. Multifunctional Material Systems: A State-of-the-art Review [J].Composite Structures，2016，151：3-35.
14. [14] YAN C F，LI S J，YANG L P，et al.Investigation of FEF process liquid phase migration using orthogonal design of experiments [J].Rapid Prototyping Journal，2019，25（2）：388-396.
15. [15] MARATTUKALAM J J，KARLSSON D，PACHECO V，et al. The Effect of Laser Scanning Strategies on Texture, Mechanical Properties, and Site-Specific Grain Orientation in Selective Laser Melted 316L SS [J/OL].Materials & Design，2020，193：108852[2025-10-23].https://www.sciencedirect.com/science/article/pii/S0264127520303865.

Funding

National Natural Science Foundation of China Project (52066006)

About the authors

Wang Yaoqian (August 1998-), male, Han ethnicity, from Zhoukou, Henan Province, is currently pursuing a master's degree in SLM additive manufacturing and material design characterization.