Author Affiliations
1School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China2Laboratory of Mechanics in Advanced Manufacturing, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China3The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, Chinashow less
Fig. 1. Mechanism for generating hollow-ring laser spot
[21] Fig. 2. Laser deposited specimen. (a) Front view; (b) top view
Fig. 3. Geometrical model and meshing. (a) Geometrical model; (b) local view of mesh
Fig. 4. Measured and simulated residual stresses
Fig. 5. Stress field and deformation of thin-wall part after deposition. (a) S11; (b) S22; (c) S33; (d) Mises stress; (e) schematic of deformation
Fig. 6. Stress component S11 of thin-walled parts with different heights. (a) 1 layer; (b) 11 layers; (c) 21 layers; (d) 31 layers; (e) 41 layers; (f) 50 layers
Fig. 7. S11 distribution. (a) S11 distributions along height of thin-walled part with different heights; (b) schematic of vertical path; (c) critical point position versus height of thin-walled part; (d) boundary stress versus height of thin-walled part
Fig. 8. S33 distributions along path 2 of thin-walled parts with different heights
Fig. 9. S33 distributions at bottom of thin-walled parts with different heights
Fig. 10. Stress analysis of isolated body
Fig. 11. S11 distributions along path 3 of thin-walled parts with different heights
Fig. 12. S11 distributions at top of thin-walled parts with different heights
Parameter | Content |
---|
Powder diameter /μm | 50‒100 | Laser power /W | 800 | Laser beam shape | Ring | Outside diameter of laser beam /mm | 2.0 | Inside diameter of laser beam /mm | 1.3 | Scanning speed /(mm⋅s-1) | 6 | Powder feed rate /(g⋅min-1) | 10.9 | Layer thickness /mm | 0.3 |
|
Table 1. Experimental process parameters
Point No. | 1 | 2 | 3 | 4 |
---|
Residual stress /MPa | 83.2±212 | 242±138 | 298±156 | -290±216 |
|
Table 2. Test results of residual stress
Parameter | Content |
---|
Density ρ /(kg⋅m-3) | 8000 | Specific heat Cp /(J⋅kg-1⋅K-1) | 600 | Conductivity of solid ks/(W⋅m-2⋅K-1) | 30 | Melting point Tm /K | 1673 | Latent heat L /(kJ⋅kg-1) | 300 | Conductivity of liquid kl /(W⋅m-2⋅K-1) | 30+10(T-1300) | Absorptivity A | 0.35 | Coefficient of convection h /(W⋅m-2⋅K-1) | 30 | Emissivity ε0 | 0.8 |
|
Table 3. Thermo-physical parameters of 316L stainless steel
[15, 25] Temperature /℃ | Young's modulus /GPa | Yield strength /MPa | Poisson's ratio | Thermal expansion coefficient /K-1 |
---|
20 | 195.6 | 297 | 0.29 | 1.5×10-5 | 200 | 185.7 | 221 | 0.29 | 1.5×10-5 | 400 | 172.6 | 202 | 0.29 | 1.5×10-5 | 700 | 144.1 | 99 | 0.29 | 1.5×10-5 | 1000 | 100.0 | 89 | 0.29 | 1.5×10-5 | 1200 | 57.0 | 59 | 0.29 | 1.5×10-5 |
|
Table 4. Mechanical performance parameters of 316L stainless steel
[15, 25]