PSI - Issue 24
Maria Rita Ridolfi et al. / Procedia Structural Integrity 24 (2019) 370 – 380 Maria Rita Ridolfi et al. / Structural Integrity Procedia 00 (2019) 000 – 000
375
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In the second stage, height h and are varied with varying laser parameters until fitting measured values of depth and width. In particular, absorptivity increases with increasing the input laser specific energy until reaching a plateau at a value close to unity. Laser efficiency has been kept constant and equal to 0.85. Table 1 resumes the main thermo-physical parameters for the three alloys.
Table 1 . Thermo-physical properties of the three alloys used for the model calibration.
Metal alloy
Ti6Al4V
INC625
Al7050
Density (kg m -3 )
4000 1986 1970
8440 1607 1513
2810
Liquidus temperature: T liq (K) Solidus temperature: T sol (K)
906 787
Specific heat (J kg -1 K -1 )
ambient temperature
550 830 980
440 650 670
860
T sol T liq
1050 1120
Thermal conductivity (W m -1 K -1 )
ambient temperature
5
11 30 30 90
117 156
T sol T liq
32 32 96
87
T>T liq
148
Latent heat of fusion (J m 3 ) Boiling temperature (K) Reflectivity at 1.06 m
1.4 10 9
1.99 10 9
1.05 10 9
3560 0.52
3003 0.71
2793 0.65
5. Results
The comparison between measured and calculated cross sectional data are shown in Fig. 3, in terms of width and depth data concerning the analysis performed on Ti6Al4V (Dilip et al. (2017)) and Al7050 (Qi et al. (2017)), respectively in Fig 3 (a) and (c), and of cross sectional area for Inconel 625 (Montgomery et al. (2015)) in Fig. 3 (b).
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