Authors are strongly recommended to review the whole manuscript carefully as stated below.
1. The abbreviations should be removed from the abstract.
2. The abstract does not have any significant values for the most important findings of the research.
3. The research gap and problem isn't obtained in the abstract.
4. The testing conditions and investigated parameters were not specified in the abstract.
5. The keywords are limited to six only.
6. The authors should write the details of the investigated parameters in this novelty paragraph.
7. A composition between the results of this article and other published works should be included.
8. The composition of the matrix investigated should be included.
9. What is the basis for choosing the counterpart of the tribological system?
10. The wear and friction reduction mechanisms were not well discussed. The authors did good amount of experiments to characterize the sliding surface using different experimental tools, and those results could be better discussed and linked to the underlying mechanism. The authors are encouraged to read and use of the well explained wear mechanisms in these papers;
a. F.A. Essa, Jingui Yu, Ammar H. Elsheikh, M.M. Tawfik. A New M50 Matrix Composite Sintered with a Hybrid Sns/Zno Nanoscale Solid Lubricants: An Experimental Investigation. Materials Research Express. 6 (2019) 116523.
b. Ammar H. Elsheikh, Jingui Yu, Ravishankar Sathyamurthy, M.M. Tawfik, S. Shanmugan, F.A. Essa. Improving the tribological properties of AISI M50 steel using Sns/Zno solid lubricants. Journal of Alloys and Compounds. 821 (2020) 153494.
c. F.A. Essa, Qiaoxin Zhang, Xingjiu Huang, Ahmed Mohamed Mahmoud Ibrahim, Mohamed Kamal Ahmed Ali, Mohamed A. A. Abdelkareem, Ahmed Elagouz. Improved friction and wear of M50 steel composites incorporated with ZnO as a solid lubricant with different concentrations under different loads. Journal of Materials Engineering and Performance; 26(10), October 2017. 4855–4866.
11. Grammatical errors make the manuscript a little challenging to read.

Accept.