The invention relates to a method for preparing a low-temperature lead-free near zero expansion
microcrystalline ceramic coating, belonging to the technical field of specific and functional
ceramic. The method comprises the following steps: uniformly performing
dry mixing on one or two of low temperature clinker 2,
spodumene melt or eucryptite melt in an arbitrary proportion, one or two or three of low temperature clinker I,
zirconium tungstate powder, an additive I or an additive 2 in an arbitrary proportion and a nucleating agent; melting the mixture in a
Muffle furnace, and preserving the temperature of between 950 and 1,200 DEG C for 0.5 to 1h; pouring the
molten glass fluid on a preheated stainless steel plate; continuously heating the
molten glass fluid to 750 DEG C in the
Muffle furnace at the temperature of between 560 and 650 DEG C, and preserving the temperature for 1 to 4h; naturally cooling the glass fluid to
room temperature, crushing to obtain
composite ceramic powder; adding a plasticizing agent and deionized water into the
composite ceramic powder to prepare
slurry; and
coating the
slurry on the surface of a matrix to sinter at the temperature of between 600 and 650 DEG C to obtain a composite inorganic
microcrystalline ceramic coating. The method is scientific and reasonable, simple and practicable, and is convenient to implement; and the prepared coating material is water proof, is lead free, can be used at low temperature, and has near zero
linear expansion coefficient.