Formula, preparation method and use method for compound phosphate coating

The invention discloses a formula for a composite phosphate coating. According to the invention, aluminum phosphate, zinc phosphate and lithium phosphate are mixed and reacted in low-concentration phosphoric acid according to a certain proportion to prepare a coating solution, and then a graphite clamp is soaked in the solution and then dried for a certain period of time, so a uniform phosphate coating can be formed on the surface layer of the graphite clamp. According to the prepared composite phosphate coating, it can be guaranteed that the graphite clamp has good stability within 600 DEG Cand cannot be corroded and consumed in a hydrofluoric acid solution, the conductivity of the graphite clamp cannot be damaged, and effective and good protection on the graphite clamp is achieved. 本发明公开了一种复合型磷酸盐涂层配方，用磷酸铝、磷酸锌、磷酸锂按照一定比例在低浓度的磷酸中混合反应制备而成涂层溶液，然后用此溶液对石墨夹具进行一定时间的浸泡烘干，就可在石墨夹具的表层形成一层均匀的磷酸盐涂层。本发明制备的复合型磷酸盐涂层，既能保证石墨夹具在600℃范围内具有良好的稳定性，也不会在氢氟酸溶液中腐蚀消耗掉，并且不会破坏石墨夹具的导电性能，实现了对石墨夹具有效良好保护。