Add borate. Borate is a high-temperature solid lubricant, which shows excellent lubrication performance in molten state. When the temperature exceeds 480℃, it has hydrodynamic effect, and when it exceeds 760℃, it acts as boundary lubricant. At high temperature, boric acid reacts with metal oxides to form glass. The low friction of boron sulfide at high temperature is attributed to boric acid. In addition, various glasses, such as lead borate glass, lead borosilicate glass, aluminum silicate glass, etc. , can be used in the temperature range of 500 ~ 800℃, and silicon glass can even be used at high temperature above 1 100℃. The disadvantage of glass lubrication is that it is difficult to remove from the lubricated surface.
As for what you said, "It feels hard when painted by hand, and the drawn silk will not change when burned", it has nothing to do with whether it is high-temperature grease or not, but the thickening agent he uses has a high proportion.