Preparation Of Blue Pigment And The Application In The Laser Marking On Ceramic Glaze

Laser marking on a smooth glazed ceramic is a new application of laser. It is also a major breakthrough in ceramic decorating, which subverting the traditional understanding of laser marking. In the conventional laser marking process, the high energy density of laser is directly irradiating on the article, leaving the scanning path of the laser engraved into the surface of article. This direct way of marking imprinted on a ceramic glaze, could make the integrity and aesthetics of ceramic products to be seriously undermined. Thus the decoration method of over-glaze color and laser cladding technology can be combined. In this way, the ceramic pigment is uniformly sprayed on the ceramic glaze, irradiated by high-energy laser, and the pigment scanned by laser will attach on the glaze. Then rinse off the no-scanned part, and the pigment scanned by laser will stay. This new method of marking on glaze, make it possible to ensure that the glaze is not destroyed and the beautiful logo can be printed on glaze. This new way of laser marking is rarely reported at home and abroad. In order to confirm this new manner, the related ceramic pigment and flux that is suitable for low-temperature over-glaze color will be prepared under laboratory conditions, and then be applied in laser marking on ceramic glaze.Blue is one of the most widely used colors in the marks on ceramic glaze. According to specific electron configuration of the element in transition zone, blue colorants which containing vanadium or cobalt or copper will be prepared under laboratory conditions. And the optimum temperature and material ratio in the procedure of preparing the pigment will be determined. And experiments of XRD analysis and differential thermal analysis and color identification will be carried on. Two types of low flux – “low temperature boron-glaze and low temperature lead-glaze” that is suitable for over-glaze color is prepared. Then the new paint made by mixing the pigment and the low temperature glaze is used for marking on glaze by laser. The glaze's firing temperature and the kind of pigment are taken into account whether is suitable for laser marking on glaze. Besides, it is investigated how laser marking on glaze is affected by the parameters of laser such as the scanning speed, the power of laser and the frequency of laser.Studies have shown that : the optimal synthesis temperatures of the V-Zr Si O4 pigment, the xCoO?2-x?MgO1 SnO₂ pigment and the?CoOSiO₂? pigment are 1000 ?,1300? and 1200? respectively, the best contents of V₂O₅ is 6%wt for V-ZrSiO₄, the optimal ratio is 0.3CoO_1.7MgO1SnO₂ for x CoO?2-x?MgO1SnO₂ and the suitable proportion of Co₃O₄:SiO₂ is 30:70 in weight for the CoOSiO₂ pigment. The V-Zr SiO₄ pigment is not suitable for laser marking on glaze for its poor ability of coloring. It is better that the relationship between the low flux's firing temperature?T1? and the to be decorated glaze's firing temperature?T2? satisfies that T2- T1 > 300?. And the most appropriate scanning speed of laser is 100²00mm/s for its high efficiency and high quality. Different pigments match the different powers and frequencies of laser. The lower power and smaller frequency performs better, But only on condition that the laser can mark on glaze successfully.