Frequency Dependence of a Piezo-Resistive Method for Pressure Measurements of Laser-Induced Shock Waves in Solids

Round 1

Reviewer 1 Report

This paper presents a pressure measurements of laser-induced shock wave in two different aluminium plates using the frequency dependent Piezo-Resistive method. The experimental setup and the correction are sufficient. However, only Fig. 6 and Fig. 7 show the significant results, which is still not enough in my personal opinion. The authors should complement some more experiment data and analysis. My recommendation for this paper is it can be accepted after a major revision. The following aspect for revision can be considered:

• In the manuscript, the authors employed two different thickness plates (1.3 mm 6063-T5 and 5 mm 6061-T6). However, the mechanical properties such as yield strength, Young’s modulus are different, which can cause unknown factors for the pressure measurements. I suggest the authors use the same material with different thickness to repeat the experiment again.
• The authors should compare the measured pressure value with the Fabbro equation theoretically calculated results to verify its accuracy. I carried a rough calculation using the Fabbro equation, the pressure is around 7 GPa (The parameter I employed from the authors are I=0.77 GWcm-2, d=10 mm, t=6 ns, which corresponds to a laser energy of 3.6 J, then employed this 3.6 J laser energy and a d=1.2 mm for the pressure calculation). Please verify your work and add this analysis.
• In Fig. 6 and Fig. 7, the first pressure peak value for 5 mm thick specimen is lower than that of the 1.3 mm ( Peak pressure for the 1.3-mm thick sample is 3.8 GPa, and the 5-mm thick sample is 1.68 GPa), please give a detailed explanation for it.
• In Fig. 6 and Fig. 7, there is a compressive pressure in the loading process, can the authors give an explanation for it.
• The Table 2 should be placed near its own contents (above the2.1 Experimental setup in the section of Materials and Methods).

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript by Gonzalez-Gomero et al. reported a study of frequency dependence of a piezo-resistive method for pressure measurements of Laser-Induced Shock  waves in solids. These results are interesting and it will be helpful for researchers interested in measuring any pressure/shock wave induced by a laser. However, several problems were found in the text and had to be clarified before possible publication.

 

176:"We chose in this study aluminum blocks"

Al has relatively high reflectivity at the wavelength of 1064 nm. Generally, black coating can be applied on the Al surface for laser shock peening. Please discuss or specify this effect.

 

187:"to focus the laser beam onto a spot diameter of about 1.2 mm on the sample surface." Provide the laser fluence on the sample.

 

199:"We measure the pressure induced by the shock wave embedding a manganin piezo-resistive

sensor (VISHAY LM-SS-125CH-048), in the back of the sample probe at a distance d = 3 mm below the laser ..." -> How to attach the piezo sensor to the backside of the Al sample? If you use a material to attach the sample, it can distort the pressure signals as well as any internal reflection of the wave. Please discuss this issue.

 

284: "We refer to the positive peak as a 284 pressure peak, and a negative peak is a compression peak." -> What is the difference between the pressure peak and the compression peak?

 

311: Table 2 can be moved to "2. Materials and Methods".

 

End of file.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This paper can be accepted, and there is no more comments.