Investigation of Low Cycle Fatigue Behaviors of Inertia-Friction-Welded Joints of the TC21 Titanium Alloy

Round 1

Reviewer 1 Report

Fig. 1 No phase markings in the photo

Line 84 - unclear description. Was the joint 70mm long? How was it determined?

The relations 1 and 2 for true stress and strain shown in lines 149 and 151 are generally known and presented in most academic textbooks. It seems that it is not necessary to present them in a scientific publication.

The work does not present the microstructural structure of the joint. The results of nanohardness measurements are important, however, to fully understand the cracking process, it is necessary to analyze the joint structure. It seems that the authors have omitted an important area of ​​joint microstructural research. It would be extremely interesting to assess the size of the grain, the way of arranging the phases, this information is missing in the presented work. The assessment of the structure would allow to explain the phenomena occurring during the stretching of the samples and the location of the plastic deformation outside the joint area.

The work is interesting and developmental, but it should be extended to include microstructural studies of the joint. This would allow for a better understanding of the mechanism of nucleation and development of fatigue cracks as well as the decohesion process in the analyzed alloy.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper discusses about the Investigation of Low Cycle Fatigue Behaviors of Inertia-Friction-Welded Joints of TC21 Titanium Alloy. In this experimental study, microhardness, tensile properties, and low cycle fatigue (LCF) behaviors were evaluated on TC21 Titanium Alloy based welded joint. Overall, the manuscript seems good to publish but some minor revisions need to be addressed in the current form of the manuscript. These are:

·       Explain the reason for choosing the range of strain between 0.9% amplitude to 0.6% amplitude?

·       In Fig. 5 (a), change the spelling mistake ‘ture’ to ‘true’

·       Improve the Fig. 7 quality as the figure is blurry.

 

Hence, reframing of the manuscript should be done.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for considering the comments. I wish you further success.