**4. Conclusions**

The effect of the friction pair materials on the antifriction behaviors of a-Si:H films is investigated under high temperature in open air and super-low friction mechanism of a-Si:H films-related friction system under high temperature is also discussed in the present paper. Conclusions can be summarized as follows.


**Author Contributions:** Conceptualization, Q.Z.; methodology, L.Q.; software, Q.Z.; validation, Q.Z.; Formal Analysis, L.Q.; Investigation, Q.Z.; Resources, Q.Z.; Data Curation, Q.Z.; Writing—Original Draft Preparation, Q.Z.; Writing—Review and Editing, Q.Z. Visualization, L.Q.; Supervision, Q.Z.; Project Administration, Q.Z.; Funding Acquisition, Q.Z.

**Funding:** The present work is funded by the National Natural Science Foundation of China (No. 51675409), Natural Science Basic Research Plan in Shaanxi Province of China (No. 2019JM-274), the Fundamental Research Funds for the Central Universities (No. xjj2017163) and the Open Project Program of Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development (No. BIPT2018001), and the key project of Shaanxi province Science and Technology Department (No. 2017ZDXM-GY-115).

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. All authors agree to submit the report for publication.
