Defect formation mechanism and suppression strategy in additively manufactured tungsten grid thin-wall structures via laser powder bed fusion

Jiang，Menglong1; Yang，Yongqiang1; Han，Changjun1; Liu，Jian2; Yan，Ming3; Yang，Chao1; Wei，Shaochong4,5; Lu，Haifeng4,5; Wang，Di1

2024-06-30

10.1016/j.jmapro.2024.04.042

Journal of Manufacturing Processes   影响因子和分区

1526-6125

Tungsten grid thin-wall structures are extensively utilized as ray filtering parts in medical equipment and nuclear industries. In this work, tungsten grid thin-wall structures with a wall thickness of approximately 100 μm were fabricated via laser powder bed fusion (LPBF) additive manufacturing technology. Post-treatments were employed to suppress the defects generated in LPBF-printed tungsten grid thin-wall structures, and the mechanisms of the defect formation and suppression were discussed. The adhesions attached to the wall surface were effectively eliminated by employing chemical corrosion and sandblasting, resulting in improved values of top and lateral surface roughness at 6.4 μm and 1.65 μm, respectively. The thin-wall structure annealed at 1400 °C presented the highest relative density of 98.28 % and unique microstructure with its lateral surface exhibiting elongated columnar grains in thin wall areas. Micro-defects including pores and cracks were observed around grain boundaries. The micro-defects deteriorated when annealed below the recrystallization temperature of 1300 °C, whereas they were effectively suppressed when annealed at 1400 °C. Consequently, this sample group exhibited exceptional mechanical properties. The stress experienced during the initial collapse in compression testing of the thin-wall structures annealed at 1400 °C was calculated to be 100.61 MPa. Subsequently, through a nano-indentation testing, the hardness and Young's modulus were measured as 9.15 GPa and 153.41 GPa respectively in thin-wall area, while in intersection area they were measured as 9.96 GPa and 381.44 GPa. The enhancement in mechanical properties of annealed tungsten grid thin-wall structures was attributed to gas pore release, diffusion densification and reduced residual stress.

Laser powder bed fusion Suppression of defects Tungsten grid thin-wall structure

SCI ; EI

英语

其他

20241615939306

Additives ; Compression testing ; Corrosion ; Elastic moduli ; Grain boundaries ; Hardness ; Indentation ; Nuclear industry ; Surface roughness

Heat Treatment Processes:537.1 ; Chemical Agents and Basic Industrial Chemicals:803 ; Physical Properties of Gases, Liquids and Solids:931.2 ; Materials Science:951

2-s2.0-85190451277

Scopus

1.School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou,510641,China
2.Guangzhou Laseradd Technology Co.,LTD,Guangzhou,511300,China
3.Department of Materials Science and Engineering,Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials,Southern University of Science and Technology,Shenzhen,518055,China
4.Suzhou Nuclear Power Research Institute,Suzhou,215004,China
5.National Engineering Research Center for Nuclear Power Plant Safety & Reliability,Suzhou,215004,China

Jiang，Menglong,Yang，Yongqiang,Han，Changjun,et al. Defect formation mechanism and suppression strategy in additively manufactured tungsten grid thin-wall structures via laser powder bed fusion[J]. Journal of Manufacturing Processes,2024,120:222-233.

Jiang，Menglong.,Yang，Yongqiang.,Han，Changjun.,Liu，Jian.,Yan，Ming.,...&Wang，Di.(2024).Defect formation mechanism and suppression strategy in additively manufactured tungsten grid thin-wall structures via laser powder bed fusion.Journal of Manufacturing Processes,120,222-233.

Jiang，Menglong,et al."Defect formation mechanism and suppression strategy in additively manufactured tungsten grid thin-wall structures via laser powder bed fusion".Journal of Manufacturing Processes 120(2024):222-233.