Properties of the Ti and Ti-6Al-4V plates treated with laser pulses in various atmospheres.
| Sample | Condition | Surface composition (atom%) | Contact angle (°) | Emissivitye (%) | Absorptivityf (%) | Surface RoughnessgRa (μm) | |
|---|---|---|---|---|---|---|---|
| X (=Cl, Br, I) | O | ||||||
| Ti | Untreated | — | 19.5 ± 1.2 | 45 ± 3 | 21 ± 1 | 67 | 0.34 |
| TiAlV | Untreated | — | 17.4 ± 2.0 | 32 ± 3 | 20 ± 1 | 67 | 0.58 |
| Ti–refa | N2a | — | 12.4 ± 0.7c | →0d | 67 ± 2 | 98 | 1.88 |
| Ti–air | Air | — | 63.2 ± 3.7 | 55 ± 3 | 46 ± 4 | 95 | 1.56 |
| TiAlV–air | Air | — | 50.8 ± 2.4 | 58 ± 3 | 54 ± 2 | 96 | 1.69 |
| Ti–I2 | Air + I2 | 0.0 | 65.8 ± 3.0 | 54 ± 3 | 47 ± 2 | 95 | 1.12 |
| TiAlV–I2 | Air + I2 | 0.0 | 50.2 ± 2.3 | 56 ± 3 | 54 ± 2 | 96 | 1.24 |
| Ti–vac | 3 mbar | — | 57.0 ± 3.1 | 17 ± 3 | — | — | 1.25 |
| Ti–vac–I2 | 3 mbar + I2 | 0.7 ± 0.05 | 63.5 ± 3.6 | →0 | — | — | 1.23 |
| Ti–Br2 | Air + Br2 | 0.2 ± 0.02 | 71.1 ± 3.8 | →0 | 75 ± 5 | 96 | 2.34 |
| TiAlV–Br2 | Air + Br2 | 0.0 | 68.2 ± 3.6 | →0 | 71 ± 5 | 97 | 2.55 |
| TiAlV–Cl2 | Air + Cl2b | 0.4 ± 0.03 | 16.0 ± 1.4 | 34 ± 3 | 24 ± 4 | 59 | 0.74 |
| Ti–CHCl3 | Air + CHCl3 | <0.1 | 63.9 ± 3.9 | 66 ± 3 | 56 ± 9 | 82 | 0.78 |
| TiAlV–CHCl3 | Air + CHCl3 | <0.1 | 63.1 ± 3.7 | 72 ± 3 | 55 ± 8 | 87 | 0.57 |
a
Processed on a Ti:sapphire laser setup under N2 for comparison (see Fig. 1g).
b
600 mbar air/400 mbar Cl2.
c
N2: 16.1%.
d
Increases to >140° after some days.
e
Measured at 100 °C.
f
At 600 nm; calcd from diffuse reflectance spectra.
g
From LSM.