High-magnification photomicrographs of the M0S2 film wear track after one kilocycle sliding in dry argon. On the polished and sandblasted substrates, the MoS2 film was not continuous; however, on the sanded substrate, a more continuous film was produced. Because the longest lives were obtained on the sandblasted substrate, film continuity was not the most important factor in determining wear life. In the first part of this investigation, it was found that the failure mechanism for M0S2 films applied to sanded substrates was the cracking and spalling of the continuous, metallic-colored MoS2 films. This, coupled with the tendency of the MoS2 to flow transversely outward on the film wear track, gradually depleted the films. Very little cracking or spalling was observed for films applied to polished substrates. The failure mechanism seemed to be solely the transverse flow's depletion of the coalesced MoS2 films. Figure 14 gives high-magnification photomicrographs of the wear tracks on the M0S2 films applied to a polished substrate after 60, 700, and 940 kilocycles of sliding. The thinning and gradual depletion of the films can be seen by comparing the surfaces at 60 and 700 kilocycles of sliding. When the films became too thin, metal-to-metal contact occurred, producing fine, powdery metallic debris. If only a small amount of debris was produced, the films could reheal, and only a spike in the friction coefficient trace resulted. However, at some point, the production of fine metallic debris became too great, causing the friction to increase and bands of powdery material to be created around the wear track—this powdery buildup on the wear track at failure. If you are looking for high quality, high purity, and cost-effective Molybdenum disulfide or the latest price, please email contact mis-asia.