Fig. 1. Gaussian heat source model
Fig. 2. Parameters of thermophysical properties for Ti6Al4V at different temperatures. (a) Conductivity; (b) specific heat; (c) density; (d) emissivity
Fig. 3. Finite element model
Fig. 4. Laser scanning path. (a) Long-side scanning; (b) short-side scanning
Fig. 5. Distribution of the temperature field. (a) Long-side scanning; (b) short-side scanning
Fig. 6. Comparison of temperature results. (a) Temperature standard deviation; (b) temperature gradient
Fig. 7. Change of temperature gradient with time at points A, B, and C. (a) Long-side scanning; (b) short-side scanning
Fig. 8. Comparison of scanning results of temperature. (a) Temperature standard deviation of long-side scanning; (b) temperature gradient of long-side scanning; (c) temperature standard deviation of short-side scanning; (d) temperature gradient of short-side scanning
Fig. 9. Experimental samples. (a) Experimental sample of long-side scanning; (b) experimental sample of short-side scanning
Fig. 10. Distribution of residual stress
Fig. 11. Residual stress value under preheating conditions. (a) Long-side scanning; (b) short-side scanning
Fig. 12. Metallographic diagrams of the formed part. (a) Long-side scanning at 20 ℃; (b) long-side scanning at 300 ℃; (c) short-side scanning at 20 ℃; (d) short-side scanning at 300 ℃
Parameter | Value |
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Laser power P /WLaser velocity V /(m·s-1)Spot size D /μmHatch spacing δ /μmPowder layer thickness θ /μm | 160100020020040 | Powder initial temperature T0/℃ | 25 |
|
Table 1. Finite element analysis parameters