Nano-scale coating wear measurement by introducing Raman-sensing underlayer

Probing the Tribochemical Impact on Wear Rate Dynamics of Hydrogenated Amorphous Carbon via Raman-Based Profilometry

“…However, the mechanisms about which type of product dominates the wear process are still not fully understood. In this study, for the first time, it is reported that the wear behavior of a-C:H coatings with MoDTC as a lubricating additive accelerates during the test in contrast to the condition lubricated by pure PAO . Based on the above results, a two-stage wear process was proposed to explain the wear acceleration mechanism as shown in Figure .…”

“…Raman-Based Profilometry for Tribofilm Detection. In our previous study, 19 an accurate Raman-based coating thickness quantification method was established by introducing a silicon layer with a strong Raman signal under the target coatings of a-C:H. As shown in Figure S4, the Raman signal intensity of the silicon underlayer will be attenuated in a-C:H due to absorption and reflection. Based on Beer's law, 20 the relationship between the thickness of a-C:H and the Raman intensity of attenuated silicon signal was constructed by eq 5 in Section S1.1.…”

“…Detailed information of the Raman-based coating thickness quantification process can be found in Section S1.1 and our previous study. 19 In this study, this proposed approach was employed to detect the formation and evolution of additive-derived tribofilms on the coating surface in the tribological process. As shown in Figure 2 After removing the oil, the Raman-based approach was first used to quantify the wear depth via the same process as stated in the last section.…”

“…In this study, for the first time, it is reported that the wear behavior of a-C:H coatings with MoDTC as a lubricating additive accelerates during the test in contrast to the condition lubricated by pure PAO. 19 Based on the above results, a two-stage wear process was proposed to explain the wear acceleration mechanism as shown in Figure 6. It is well accepted that MoS 2 is always formed accompanied by MoO 3 formation.…”

“…It has also been demonstrated that the Raman intensity of silicon decreased logarithmically with increasing a-C:H thickness. Detailed information of the Raman-based coating thickness quantification process can be found in Section S1.1 and our previous study …”